use super::activity::ACTIVITY_KEEP;
use super::migrations::SCHEMA_VERSION;
use super::*;
use crate::control::{ActivityEntry, ActivityKind};
use crate::localindex::LocalEntry;
use proton_drive_rs::proton_sdk::ids::NodeUid;
use proton_drive_rs::{Node, NodeKind};
use serde_json::json;

/// `Db::open` applies the pragmas that `open_in_memory` skips, so the WAL
/// settings can only be checked against a real file.
#[test]
fn open_bounds_the_wal_size() {
    let path = std::env::temp_dir().join(format!("pdfs-db-wal-{}.db", std::process::id()));
    let _ = std::fs::remove_file(&path);
    let db = Db::open(&path).unwrap();
    let conn = db.conn.lock();

    let mode: String = conn
        .query_row("PRAGMA journal_mode", [], |r| r.get(0))
        .unwrap();
    assert_eq!(mode, "wal");
    // Without this the WAL is reused in place but never shrinks, so one
    // oversized transaction strands its high-water mark on disk forever.
    let limit: i64 = conn
        .query_row("PRAGMA journal_size_limit", [], |r| r.get(0))
        .unwrap();
    assert_eq!(limit, WAL_SIZE_LIMIT);

    // Without a busy timeout the default is 0: a lock held by anyone else fails
    // the statement instantly instead of waiting for it to clear.
    let busy: i64 = conn
        .query_row("PRAGMA busy_timeout", [], |r| r.get(0))
        .unwrap();
    assert_eq!(busy, BUSY_TIMEOUT.as_millis() as i64);

    drop(conn);
    drop(db);
    let _ = std::fs::remove_file(&path);
}

/// A second connection to the same file — a hand-started `pdfs mount` alongside
/// the systemd service, a backup tool, a stray `sqlite3` session — holds a write
/// lock briefly. Our write must wait for it rather than failing on the spot.
///
/// **This passed before the busy timeout was set explicitly**, because rusqlite
/// already applies one. It is kept as a characterisation test, not as evidence
/// of a fix: it states the behaviour the daemon relies on, so that losing it
/// (dropping the pragma, or a dependency changing its default) fails here rather
/// than in front of a user.
#[test]
fn a_write_waits_for_a_competing_writer() {
    use std::time::Duration;

    let path = std::env::temp_dir().join(format!("pdfs-db-busy-{}.db", std::process::id()));
    let _ = std::fs::remove_file(&path);
    let db = Db::open(&path).unwrap();

    // A second process's connection takes an exclusive write lock and holds it
    // for a moment, as any real transaction would.
    let holder = {
        let path = path.clone();
        std::thread::spawn(move || {
            let other = rusqlite::Connection::open(&path).unwrap();
            other.busy_timeout(Duration::from_secs(5)).unwrap();
            other.execute_batch("BEGIN IMMEDIATE").unwrap();
            std::thread::sleep(Duration::from_millis(300));
            other.execute_batch("COMMIT").unwrap();
        })
    };
    // Let the holder actually acquire the lock before we contend for it.
    std::thread::sleep(Duration::from_millis(50));

    // This is the assertion: it blocks until the holder commits, rather than
    // returning SQLITE_BUSY.
    db.set_state_i64("busy_probe", 7).unwrap();

    holder.join().unwrap();
    assert_eq!(db.state_i64("busy_probe").unwrap(), Some(7));

    drop(db);
    let _ = std::fs::remove_file(&path);
}
use proton_drive_rs::proton_sdk::ids::{LinkId, VolumeId};

fn uid(link: &str) -> NodeUid {
    NodeUid::new(VolumeId::from("vol"), LinkId::from(link))
}

fn now_test_id() -> u64 {
    use std::sync::atomic::{AtomicU64, Ordering};
    static NEXT: AtomicU64 = AtomicU64::new(0);
    NEXT.fetch_add(1, Ordering::Relaxed)
}

// `NodeVerification` is not re-exported, so build test nodes by
// deserializing JSON (the field has a serde default and can be omitted).
fn node_from(parent: serde_json::Value, link: &str, name: &str, kind: serde_json::Value) -> Node {
    let v = serde_json::json!({
        "uid": {"volume_id": "vol", "link_id": link},
        "parent_uid": parent,
        "kind": kind,
        "name": name,
        "creation_time": 100,
        "modification_time": 200,
        "trashed": false,
        "signature_email": null,
    });
    serde_json::from_value(v).unwrap()
}

#[test]
fn photos_replace_keeps_what_was_learned_and_drops_what_left() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow {
            media_type: Some("video/mp4".into()),
            favorite: Some(true),
            ..TimelineRow::new("p1", 300)
        },
        TimelineRow::new("p2", 200),
        TimelineRow::new("p3", 100),
    ])
    .unwrap();

    // A thumbnail attempt teaches us p1's ratio and that p2 can never have one.
    db.photo_set_thumb("p1", THUMB_HAVE, Some(1.5)).unwrap();
    db.photo_set_thumb("p2", THUMB_NONE, None).unwrap();

    // The next refresh brings a new photo, keeps p1 and p2, and loses p3.
    // p1's media type arrives as `None` this time and must not be forgotten.
    db.photos_replace(&[
        TimelineRow {
            name: Some("new.jpg".into()),
            favorite: Some(false),
            ..TimelineRow::new("p0", 400)
        },
        TimelineRow::new("p1", 300),
        TimelineRow::new("p2", 200),
    ])
    .unwrap();

    let page = db.photos_page(0, 10, None, None, false, false).unwrap();
    assert_eq!(
        page.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["p0", "p1", "p2"],
        "server order is preserved, and the dropped photo is gone"
    );
    assert_eq!(page[0].name.as_deref(), Some("new.jpg"));
    // Ratios and verdicts cost a download to rediscover: they survive a refresh.
    assert_eq!(page[1].ratio, Some(1.5));
    assert_eq!(page[1].thumb_state, THUMB_HAVE);
    assert_eq!(page[2].thumb_state, THUMB_NONE);
    // A photo we know nothing about yet starts blank.
    assert_eq!(page[0].ratio, None);
    assert_eq!(page[0].thumb_state, THUMB_UNKNOWN);
    // Media type is learned-and-kept like the ratio: p1 keeps the video type
    // it was first seen with even though the later refresh carried `None`, so
    // it stays classified as a video.
    assert_eq!(page[1].kind, crate::control::PhotoKind::Video);

    assert_eq!(db.photos_count().unwrap(), 3);
    // The counts break down by tab, and a filtered page returns only its tab.
    assert_eq!(db.photos_counts().unwrap(), (2, 1, 0));
    let videos = db
        .photos_page(
            0,
            10,
            Some(crate::control::PhotoKind::Video),
            None,
            false,
            false,
        )
        .unwrap();
    assert_eq!(
        videos.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["p1"]
    );
    let by_uid = db.photos_by_uid(&["p2".into()]).unwrap();
    assert_eq!(by_uid.len(), 1);
    assert_eq!(by_uid[0].capture_time, 200);

    // A date-range page keeps only the window's photos: [150, 350) is p1+p2,
    // not p0 at 400. Combined with a kind filter both conditions apply.
    let ranged = db
        .photos_page(0, 10, None, Some((150, 350)), false, false)
        .unwrap();
    assert_eq!(
        ranged.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["p1", "p2"]
    );
    let ranged_video = db
        .photos_page(
            0,
            10,
            Some(crate::control::PhotoKind::Video),
            Some((150, 350)),
            false,
            false,
        )
        .unwrap();
    assert_eq!(
        ranged_video
            .iter()
            .map(|p| p.uid.as_str())
            .collect::<Vec<_>>(),
        ["p1"]
    );
    // All three surviving photos sit in the same (1970-01) local month.
    let months = db.photos_months(None).unwrap();
    assert_eq!(months.len(), 1);
    assert_eq!(months[0].2, 3);
}

#[test]
fn favorites_are_remembered_across_refreshes_and_filter_a_page() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow {
            favorite: Some(true),
            ..TimelineRow::new("p1", 300)
        },
        TimelineRow {
            favorite: Some(false),
            ..TimelineRow::new("p2", 200)
        },
    ])
    .unwrap();
    let favorites = db.photos_page(0, 10, None, None, true, false).unwrap();
    assert_eq!(
        favorites.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["p1"],
        "only the favorited photo is in a favorites page"
    );

    // A local toggle survives a refresh that could not resolve the photo's node
    // (`None`), and loses to one that could.
    db.photos_set_favorite("p2", true).unwrap();
    db.photos_replace(&[
        TimelineRow {
            favorite: Some(false),
            ..TimelineRow::new("p1", 300)
        },
        TimelineRow::new("p2", 200),
    ])
    .unwrap();
    let favorites = db.photos_page(0, 10, None, None, true, false).unwrap();
    assert_eq!(
        favorites.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["p2"],
        "the server's answer wins where it has one; the local flag holds where it doesn't"
    );
    assert!(db.photos_by_uid(&["p2".into()]).unwrap()[0].favorite);
}

/// The strip shows the same calendar day in earlier years only: not today's
/// own photos, not the day before, and one tile per RAW+JPEG shot.
#[test]
fn on_this_day_finds_the_same_date_in_earlier_years() {
    const DAY: i64 = 86_400;
    // Noon UTC, so the local date is the same in every common time zone.
    let today = 1_781_524_800; // 2026-06-15 12:00 UTC
    let year_ago = today - 365 * DAY; // 2025-06-15
    let three_years_ago = today - (365 * 3 + 1) * DAY; // 2023-06-15, past a 29 February
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow::new("today", today),
        TimelineRow {
            name: Some("IMG_1.JPG".into()),
            ..TimelineRow::new("jpeg", year_ago)
        },
        TimelineRow {
            name: Some("IMG_1.CR2".into()),
            ..TimelineRow::new("raw", year_ago)
        },
        TimelineRow::new("day-before", year_ago - DAY),
        TimelineRow::new("older", three_years_ago),
    ])
    .unwrap();

    let found = db.photos_on_this_day(today, 10).unwrap();
    assert_eq!(
        found.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["jpeg", "older"]
    );
}

fn hashed(uid: &str, capture_time: i64, name: &str, hash: &str) -> TimelineRow {
    TimelineRow {
        name: Some(name.into()),
        content_hash: Some(hash.into()),
        ..TimelineRow::new(uid, capture_time)
    }
}

fn located(uid: &str, capture_time: i64, name: &str, at: (f64, f64)) -> TimelineRow {
    TimelineRow {
        name: Some(name.into()),
        location: Some(at),
        resolved_at: Some(1),
        ..TimelineRow::new(uid, capture_time)
    }
}

const BERLIN: (f64, f64) = (52.52, 13.405);
const PARIS: (f64, f64) = (48.857, 2.352);

/// Places count shots, not files, lead with the most photographed town, and
/// leave out photos with no location or taken far from any town.
#[test]
fn places_group_photos_by_the_nearest_town() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        located("b2", 500, "IMG_5.JPG", BERLIN),
        located("p1", 400, "IMG_4.JPG", PARIS),
        located("b1-jpeg", 300, "IMG_3.JPG", BERLIN),
        located("b1-raw", 300, "IMG_3.CR2", BERLIN),
        located("sea", 200, "IMG_2.JPG", (0.0, -30.0)),
        TimelineRow::new("nowhere", 100),
    ])
    .unwrap();

    let places = db.photo_places().unwrap();
    let summary: Vec<(&str, usize, &str)> = places
        .iter()
        .map(|place| {
            let city = crate::places::city(place.id).expect("a known town");
            (city.name, place.count, place.cover.uid.as_str())
        })
        .collect();
    assert_eq!(summary, [("Berlin", 2, "b2"), ("Paris", 1, "p1")]);

    let berlin: Vec<String> = db
        .photos_at_place(places[0].id, 0, 10)
        .unwrap()
        .into_iter()
        .map(|p| p.uid)
        .collect();
    assert_eq!(berlin, ["b2", "b1-jpeg"]);
}

/// A town's photos come with where each was taken, one per RAW+JPEG shot.
#[test]
fn place_photos_carry_their_own_location() {
    let db = Db::open_in_memory().unwrap();
    let kreuzberg = (52.497, 13.411);
    db.photos_replace(&[
        located("b2", 500, "IMG_5.JPG", BERLIN),
        located("b1-jpeg", 300, "IMG_3.JPG", kreuzberg),
        located("b1-raw", 300, "IMG_3.CR2", kreuzberg),
    ])
    .unwrap();
    let id = db.photo_places().unwrap()[0].id;
    let located: Vec<(String, (f64, f64))> = db
        .photo_locations_at_place(id)
        .unwrap()
        .into_iter()
        .map(|(photo, at)| (photo.uid, at))
        .collect();
    assert_eq!(
        located,
        [("b2".to_owned(), BERLIN), ("b1-jpeg".to_owned(), kreuzberg)]
    );
}

/// A refresh that skips an already-resolved photo keeps where it was taken; one
/// that reads the node again takes what the node now says.
#[test]
fn a_skipped_refresh_keeps_a_photos_location() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[located("a", 100, "IMG_1.JPG", BERLIN)])
        .unwrap();
    db.photos_replace(&[TimelineRow::new("a", 100)]).unwrap();
    assert_eq!(db.photo_places().unwrap().len(), 1);

    db.photos_replace(&[TimelineRow {
        resolved_at: Some(2),
        ..TimelineRow::new("a", 100)
    }])
    .unwrap();
    assert!(db.photo_places().unwrap().is_empty());
}

/// A copy an album holds is the one kept; the files of one RAW+JPEG shot are
/// never copies of each other; a hash only one file carries is no set.
#[test]
fn duplicates_list_the_copy_to_keep_first() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        hashed("copy", 500, "IMG_2.JPG", "h2"),
        hashed("filed", 400, "IMG_2(1).JPG", "h2"),
        hashed("jpeg", 300, "IMG_1.JPG", "h1"),
        hashed("raw", 300, "IMG_1.CR2", "h1"),
        hashed("stray", 200, "IMG_1(1).CR2", "h1"),
        hashed("alone", 100, "IMG_3.JPG", "h3"),
    ])
    .unwrap();
    db.album_photos_replace("a1", &[("filed".into(), 400, None, None)])
        .unwrap();

    let sets = db.photo_duplicates().unwrap();
    let uids: Vec<Vec<&str>> = sets
        .iter()
        .map(|set| set.iter().map(|p| p.uid.as_str()).collect())
        .collect();
    assert_eq!(uids, [vec!["filed", "copy"], vec!["jpeg", "stray"]]);
}

/// Shots that look alike form a set, one photo per shot, while a set of
/// byte-identical copies is left to the duplicate finder.
#[test]
fn similar_photos_group_by_look_and_skip_exact_copies() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        hashed("big", 500, "IMG_1.JPG", "h1"),
        hashed("small", 400, "IMG_1-small.JPG", "h2"),
        hashed("copy", 300, "IMG_2.JPG", "h3"),
        hashed("copy2", 200, "IMG_2(1).JPG", "h3"),
        hashed("other", 100, "IMG_3.JPG", "h4"),
        hashed("flat", 50, "IMG_4.JPG", "h5"),
    ])
    .unwrap();
    let look = 0x0f0f_3c3c_5a5a_9696_u64;
    db.photo_set_similar_hash("big", look).unwrap();
    db.photo_set_similar_hash("small", look ^ 0b101).unwrap();
    db.photo_set_similar_hash("copy", !look).unwrap();
    db.photo_set_similar_hash("copy2", !look).unwrap();
    db.photo_set_similar_hash("other", look ^ 0xffff_ffff)
        .unwrap();
    db.photo_set_similar_hash("flat", crate::similar::NO_HASH)
        .unwrap();

    let sets = db.photo_similar().unwrap();
    let uids: Vec<Vec<&str>> = sets
        .iter()
        .map(|set| set.iter().map(|p| p.uid.as_str()).collect())
        .collect();
    assert_eq!(uids, [vec!["small", "big"]]);
    assert_eq!(db.similar_progress().unwrap(), (6, 6));
}

/// What is left to hash skips videos and hashed shots, and a hash survives a
/// refresh unless the photo's bytes changed.
#[test]
fn similar_hashes_are_kept_until_the_photo_changes() {
    let db = Db::open_in_memory().unwrap();
    let resolved = |uid: &str, hash: &str| TimelineRow {
        resolved_at: Some(1),
        ..hashed(uid, 100, &format!("{uid}.JPG"), hash)
    };
    db.photos_replace(&[
        resolved("a", "h1"),
        resolved("b", "h2"),
        hashed("clip", 50, "clip.mp4", "h3"),
    ])
    .unwrap();
    db.photo_set_similar_hash("a", 7).unwrap();
    db.photo_set_similar_hash("b", 9).unwrap();
    let left = |db: &Db| -> Vec<String> {
        db.photos_unhashed(10)
            .unwrap()
            .into_iter()
            .map(|p| p.uid)
            .collect()
    };
    assert!(left(&db).is_empty());
    assert_eq!(db.similar_progress().unwrap(), (2, 2));

    db.photos_replace(&[
        resolved("a", "h1"),
        resolved("b", "h2-edited"),
        hashed("clip", 50, "clip.mp4", "h3"),
    ])
    .unwrap();
    assert_eq!(left(&db), ["b"]);
    assert_eq!(db.similar_progress().unwrap(), (1, 2));
}

/// Trashing the file a group is shown as leaves the rest of the group on the
/// timeline instead of pointing at a photo that is gone.
#[test]
fn deleting_a_group_representative_keeps_its_other_files() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        hashed("jpeg", 300, "IMG_1.JPG", "h1"),
        hashed("raw", 300, "IMG_1.CR2", "h2"),
    ])
    .unwrap();
    assert_eq!(
        db.photos_page(0, 10, None, None, false, false)
            .unwrap()
            .len(),
        1
    );

    db.photos_delete(&["jpeg".into()]).unwrap();
    let page = db.photos_page(0, 10, None, None, false, false).unwrap();
    assert_eq!(
        page.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["raw"]
    );
}

#[test]
fn not_in_album_hides_photos_any_album_holds() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow::new("p1", 300),
        TimelineRow::new("p2", 200),
        TimelineRow::new("p3", 100),
    ])
    .unwrap();
    db.album_photos_replace("a1", &[("p1".into(), 300, None, None)])
        .unwrap();
    db.album_photos_replace("a2", &[("p3".into(), 100, None, None)])
        .unwrap();

    let page = db.photos_page(0, 10, None, None, false, true).unwrap();
    assert_eq!(
        page.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["p2"]
    );
}

/// Filing the JPEG of a RAW+JPEG shot files the shot: the grid shows it as
/// one tile, and that tile is in an album.
#[test]
fn not_in_album_counts_a_raw_pair_as_filed() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow {
            name: Some("IMG_1234.JPG".into()),
            ..TimelineRow::new("jpeg", 300)
        },
        TimelineRow {
            name: Some("img_1234.cr2".into()),
            ..TimelineRow::new("raw", 300)
        },
        TimelineRow {
            name: Some("IMG_9999.JPG".into()),
            ..TimelineRow::new("alone", 200)
        },
    ])
    .unwrap();
    db.album_photos_replace("a1", &[("raw".into(), 300, None, None)])
        .unwrap();

    let page = db.photos_page(0, 10, None, None, false, true).unwrap();
    assert_eq!(
        page.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["alone"]
    );
}

#[test]
fn photos_page_slices_the_timeline_in_order() {
    let db = Db::open_in_memory().unwrap();
    let items: Vec<_> = (0..5)
        .map(|i| TimelineRow::new(format!("p{i}"), 500 - i as i64))
        .collect();
    db.photos_replace(&items).unwrap();

    let page = db.photos_page(2, 2, None, None, false, false).unwrap();
    assert_eq!(
        page.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["p2", "p3"]
    );
    assert!(
        db.photos_page(9, 2, None, None, false, false)
            .unwrap()
            .is_empty()
    );
}

#[test]
fn trash_replace_lists_folders_first() {
    let db = Db::open_in_memory().unwrap();
    db.trash_replace(&[
        StoredTrash {
            uid: "t1".into(),
            name: "zeta.txt".into(),
            is_dir: false,
            size: 10,
            mtime: 1,
            parent_uid: Some("t2".into()),
            trashed_at: Some(100),
        },
        StoredTrash {
            uid: "t2".into(),
            name: "Alpha".into(),
            is_dir: true,
            size: 0,
            mtime: 2,
            parent_uid: None,
            trashed_at: None,
        },
    ])
    .unwrap();

    let items = db.trash_list().unwrap();
    assert_eq!(
        items.iter().map(|i| i.name.as_str()).collect::<Vec<_>>(),
        ["Alpha", "zeta.txt"]
    );

    // The parent links come back with the rows: a restore reads the tree shape
    // from them.
    let mut parents = db.trash_parents().unwrap();
    parents.sort();
    assert_eq!(
        parents,
        [
            ("t1".to_string(), Some("t2".to_string())),
            ("t2".to_string(), None),
        ]
    );

    // The first-seen times round-trip, unknown ones included.
    let mut seen: Vec<_> = db.trash_seen().unwrap().into_iter().collect();
    seen.sort();
    assert_eq!(
        seen,
        [("t1".to_string(), Some(100)), ("t2".to_string(), None)]
    );
    assert_eq!(items[1].trashed_at, Some(100));

    // A replace is a replace: emptying the trash on the server empties it here.
    db.trash_replace(&[]).unwrap();
    assert!(db.trash_list().unwrap().is_empty());
}

#[test]
fn state_stamps_round_trip_and_clear() {
    let db = Db::open_in_memory().unwrap();
    assert_eq!(db.state_i64("photos_synced_ms").unwrap(), None);
    db.set_state_i64("photos_synced_ms", 1234).unwrap();
    assert_eq!(db.state_i64("photos_synced_ms").unwrap(), Some(1234));
    db.clear_state("photos_synced_ms").unwrap();
    assert_eq!(
        db.state_i64("photos_synced_ms").unwrap(),
        None,
        "a cleared stamp reads as never fetched, so the next request blocks on a refresh"
    );
}

fn folder(link: &str, parent: Option<&str>, name: &str) -> Node {
    let parent = match parent {
        Some(p) => serde_json::json!({"volume_id": "vol", "link_id": p}),
        None => serde_json::Value::Null,
    };
    node_from(parent, link, name, serde_json::json!("Folder"))
}

fn file(link: &str, parent: &str, name: &str, size: i64) -> Node {
    let kind = serde_json::json!({
        "File": {
            "media_type": "text/plain",
            "total_size_on_storage": size + 10,
            "claimed_size": size,
            "claimed_modification_time": null,
        }
    });
    node_from(
        serde_json::json!({"volume_id": "vol", "link_id": parent}),
        link,
        name,
        kind,
    )
}

fn foreign_folder(volume: &str, link: &str, parent: NodeUid, name: &str) -> Node {
    let mut node = folder(link, None, name);
    node.uid = NodeUid::new(VolumeId::from(volume), LinkId::from(link));
    node.parent_uid = Some(parent);
    node
}

/// Recovering the root by uid is what lets the daemon mount offline:
/// the uid is remembered in `sync_state`, the node
/// itself comes back out of `nodes`.
#[test]
fn node_by_uid_recovers_a_stored_node() {
    let db = Db::open_in_memory().unwrap();
    let root = folder("root", None, "My Files");
    db.upsert_node(&root).unwrap();
    db.set_state_str("root_uid", &root.uid.to_string()).unwrap();

    let key = db.state_str("root_uid").unwrap().unwrap();
    let got = db.node_by_uid(&key).unwrap().expect("root recovered");
    assert_eq!(got.uid, root.uid);
    assert_eq!(got.name, "My Files");
    assert!(got.is_folder());

    assert!(db.node_by_uid("vol~nope").unwrap().is_none());
    assert!(db.state_str("never_written").unwrap().is_none());
}

#[test]
fn upsert_and_load_all_roundtrip() {
    let db = Db::open_in_memory().unwrap();
    let root = folder("root", None, "My Files");
    let child = file("f1", "root", "hello.txt", 42);
    db.upsert_node(&root).unwrap();
    db.upsert_node(&child).unwrap();

    let loaded = db.load_all().unwrap();
    assert_eq!(loaded.len(), 2);
    let f = loaded.iter().find(|s| s.node.uid == uid("f1")).unwrap();
    assert_eq!(f.node.name, "hello.txt");
    assert!(!f.listed);
    match &f.node.kind {
        NodeKind::File { claimed_size, .. } => assert_eq!(*claimed_size, Some(42)),
        _ => panic!("expected file"),
    }
}

#[test]
fn upsert_nodes_and_load_all_roundtrip() {
    let db = Db::open_in_memory().unwrap();
    let root = folder("root", None, "My Files");
    let child1 = file("f1", "root", "hello.txt", 42);
    let child2 = file("f2", "root", "world.txt", 100);
    db.upsert_nodes(&[root, child1, child2]).unwrap();

    let loaded = db.load_all().unwrap();
    assert_eq!(loaded.len(), 3);
    let f1 = loaded.iter().find(|s| s.node.uid == uid("f1")).unwrap();
    assert_eq!(f1.node.name, "hello.txt");
    let f2 = loaded.iter().find(|s| s.node.uid == uid("f2")).unwrap();
    assert_eq!(f2.node.name, "world.txt");
}

#[test]
fn upsert_is_idempotent_update() {
    let db = Db::open_in_memory().unwrap();
    let mut n = folder("root", None, "My Files");
    db.upsert_node(&n).unwrap();
    n.name = "Renamed".into();
    db.upsert_node(&n).unwrap();
    let loaded = db.load_all().unwrap();
    assert_eq!(loaded.len(), 1);
    assert_eq!(loaded[0].node.name, "Renamed");
}

#[test]
fn delete_node_removes_row() {
    let db = Db::open_in_memory().unwrap();
    let n = folder("root", None, "My Files");
    db.upsert_node(&n).unwrap();
    db.delete_node(&uid("root")).unwrap();
    assert!(db.load_all().unwrap().is_empty());
}

#[test]
fn completing_trash_atomically_removes_the_op_and_retained_node() {
    let db = Db::open_in_memory().unwrap();
    let node = file("trash-me", "parent", "trash-me.txt", 4);
    let uid = node.uid.clone();
    db.upsert_node(&node).unwrap();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_TRASH.to_string(),
        uid: uid.to_string(),
        parent_uid: None,
        name: Some(node.name.clone()),
        blob_path: None,
        meta_json: None,
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();
    let op = db.pending_ops().unwrap().remove(0);

    db.complete_trash_op(op.id, &uid).unwrap();

    assert!(db.node_by_uid(&uid.to_string()).unwrap().is_none());
    assert!(db.pending_ops().unwrap().is_empty());
}

#[test]
fn children_if_listed_gated_on_flag() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&file("f1", "root", "a.txt", 1)).unwrap();
    db.upsert_node(&file("f2", "root", "b.txt", 2)).unwrap();

    // Not listed yet → unknown, force a re-fetch.
    assert!(db.children_if_listed(&uid("root")).unwrap().is_none());
    // Still known, for a caller that has nothing better while offline.
    assert_eq!(db.known_children(&uid("root")).unwrap().len(), 2);

    db.set_listed(&uid("root"), true).unwrap();
    let kids = db.children_if_listed(&uid("root")).unwrap().unwrap();
    assert_eq!(kids.len(), 2);
}

/// The shape of the `mv`-loses-the-file bug (`docs/BUGS.md` B1): a rename deletes the
/// moved node's row, so a destination left marked `listed` is rebuilt from the DB
/// without it — the file is gone from the source and absent from the destination,
/// with `rename(2)` having reported success. Clearing the flag is what forces the
/// re-enumeration that finds it again.
#[test]
fn a_deleted_child_leaves_a_listed_parent_serving_a_stale_listing() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("dst", Some("root"), "dest"))
        .unwrap();
    db.upsert_node(&file("f1", "root", "a.txt", 1)).unwrap();
    db.set_listed(&uid("dst"), true).unwrap();

    // The rename moved a.txt into `dst` server-side, then forgot the node.
    db.delete_node(&uid("f1")).unwrap();

    // `dst` is still flagged listed, so the DB fast path answers — and the file
    // it was just moved into is nowhere in the result.
    assert!(
        db.children_if_listed(&uid("dst"))
            .unwrap()
            .unwrap()
            .is_empty()
    );

    // Clearing the flag is the only thing that sends the next read to the server.
    db.set_listed(&uid("dst"), false).unwrap();
    assert!(db.children_if_listed(&uid("dst")).unwrap().is_none());
}

#[test]
fn children_if_listed_excludes_trashed() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    let mut trashed = file("f1", "root", "a.txt", 1);
    trashed.trashed = true;
    db.upsert_node(&trashed).unwrap();
    db.set_listed(&uid("root"), true).unwrap();
    assert_eq!(
        db.children_if_listed(&uid("root")).unwrap().unwrap().len(),
        0
    );
}

#[test]
fn shared_root_replacement_tombstones_without_losing_work_or_authority() {
    let db = Db::open_in_memory().unwrap();
    let own_root = folder("root", None, "My Files");
    let virtual_uid = NodeUid::new(VolumeId::from("virtual"), LinkId::from("sharedwithme"));
    let virtual_root = foreign_folder(
        "virtual",
        "sharedwithme",
        own_root.uid.clone(),
        "Shared with me",
    );
    let shared = foreign_folder("foreign", "share", virtual_uid.clone(), "Project");
    let child = foreign_folder("foreign", "child", shared.uid.clone(), "Secret");
    db.upsert_nodes(&[own_root, virtual_root, shared.clone(), child.clone()])
        .unwrap();
    db.set_share_access(&shared.uid, crate::Access::Editor)
        .unwrap();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: child.uid.to_string(),
        parent_uid: Some(shared.uid.to_string()),
        name: Some(child.name.clone()),
        blob_path: Some("/staging/shared-edit".to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();
    assert_eq!(db.search("Secret", 10).unwrap().len(), 1);

    let removed = db.publish_shared_roots(&virtual_uid, &[], &[]).unwrap();
    assert_eq!(removed, vec![shared.uid.clone()]);
    assert!(db.visible_children(&virtual_uid).unwrap().is_empty());
    assert!(
        db.node_by_uid(&shared.uid.to_string())
            .unwrap()
            .unwrap()
            .trashed
    );
    assert!(
        db.node_by_uid(&child.uid.to_string())
            .unwrap()
            .unwrap()
            .trashed
    );
    assert!(db.search("Secret", 10).unwrap().is_empty());
    assert_eq!(db.pending_ops().unwrap().len(), 1);
    assert_eq!(
        db.share_access(&shared.uid).unwrap(),
        Some(crate::Access::Viewer)
    );

    let mut reappeared = shared.clone();
    reappeared.trashed = false;
    assert!(
        db.publish_shared_roots(
            &virtual_uid,
            std::slice::from_ref(&shared.uid),
            &[PublishedSharedRoot {
                node: reappeared,
                access: crate::Access::Viewer,
            }],
        )
        .unwrap()
        .is_empty()
    );
    let restored = db.visible_children(&virtual_uid).unwrap();
    assert_eq!(restored.len(), 1);
    assert_eq!(restored[0].parent_uid.as_ref(), Some(&virtual_uid));
    assert!(!restored[0].trashed);
    assert!(
        db.node_by_uid(&child.uid.to_string())
            .unwrap()
            .unwrap()
            .trashed,
        "descendants remain hidden until their folder is re-enumerated"
    );
    assert_eq!(db.pending_ops().unwrap().len(), 1);
    assert_eq!(
        db.share_access(&shared.uid).unwrap(),
        Some(crate::Access::Viewer),
        "reappearance stays fail-closed until an observed role refresh"
    );
}

#[test]
fn shared_root_node_and_authority_publication_roll_back_together() {
    let db = Db::open_in_memory().unwrap();
    let own_root = folder("root", None, "My Files");
    let virtual_uid = NodeUid::new(VolumeId::from("virtual"), LinkId::from("sharedwithme"));
    let virtual_root = foreign_folder(
        "virtual",
        "sharedwithme",
        own_root.uid.clone(),
        "Shared with me",
    );
    let shared = foreign_folder("foreign", "share", virtual_uid.clone(), "Before");
    db.upsert_nodes(&[own_root, virtual_root, shared.clone()])
        .unwrap();
    db.set_share_access(&shared.uid, crate::Access::Viewer)
        .unwrap();
    db.set_listed(&virtual_uid, false).unwrap();
    db.with_conn(|conn| {
        conn.execute_batch(
            "CREATE TRIGGER reject_shared_authority
             BEFORE UPDATE ON share_access
             WHEN NEW.root_uid = 'foreign~share'
             BEGIN SELECT RAISE(ABORT, 'injected authority failure'); END;",
        )?;
        Ok(())
    })
    .unwrap();

    let mut changed = shared.clone();
    changed.name = "After".into();
    let result = db.publish_shared_roots(
        &virtual_uid,
        std::slice::from_ref(&shared.uid),
        &[PublishedSharedRoot {
            node: changed,
            access: crate::Access::Editor,
        }],
    );
    assert!(result.is_err());
    assert_eq!(
        db.node_by_uid(&shared.uid.to_string())
            .unwrap()
            .unwrap()
            .name,
        "Before"
    );
    assert_eq!(
        db.share_access(&shared.uid).unwrap(),
        Some(crate::Access::Viewer)
    );
    assert!(db.children_if_listed(&virtual_uid).unwrap().is_none());
}

#[test]
fn accepted_but_unmaterialized_shared_root_keeps_its_snapshot() {
    let db = Db::open_in_memory().unwrap();
    let own_root = folder("root", None, "My Files");
    let virtual_uid = NodeUid::new(VolumeId::from("virtual"), LinkId::from("sharedwithme"));
    let virtual_root = foreign_folder(
        "virtual",
        "sharedwithme",
        own_root.uid.clone(),
        "Shared with me",
    );
    let shared = foreign_folder("foreign", "share", virtual_uid.clone(), "Retained");
    db.upsert_nodes(&[own_root, virtual_root, shared.clone()])
        .unwrap();
    db.set_share_access(&shared.uid, crate::Access::Editor)
        .unwrap();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_RENAME.to_string(),
        uid: shared.uid.to_string(),
        parent_uid: Some(virtual_uid.to_string()),
        name: Some("Retained locally".to_string()),
        blob_path: None,
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();

    let removed = db
        .publish_shared_roots(&virtual_uid, std::slice::from_ref(&shared.uid), &[])
        .unwrap();
    assert!(removed.is_empty());
    assert_eq!(db.visible_children(&virtual_uid).unwrap().len(), 1);
    assert_eq!(db.pending_ops().unwrap().len(), 1);
    assert_eq!(
        db.share_access(&shared.uid).unwrap(),
        Some(crate::Access::Viewer),
        "an accepted root without verified materialized membership fails closed"
    );
}

#[test]
fn foreign_listing_reconciles_authoritative_uids_and_survives_restart_shape() {
    let db = Db::open_in_memory().unwrap();
    let own_root = folder("root", None, "My Files");
    let virtual_uid = NodeUid::new(VolumeId::from("virtual"), LinkId::from("sharedwithme"));
    let virtual_root = foreign_folder(
        "virtual",
        "sharedwithme",
        own_root.uid.clone(),
        "Shared with me",
    );
    let shared = foreign_folder("foreign", "share", virtual_uid, "Shared");
    let kept = foreign_folder("foreign", "kept", shared.uid.clone(), "Kept");
    let removed = foreign_folder("foreign", "removed", shared.uid.clone(), "Removed");
    let deep = foreign_folder("foreign", "deep", removed.uid.clone(), "Deep secret");
    db.upsert_nodes(&[
        own_root,
        virtual_root,
        shared.clone(),
        kept.clone(),
        removed.clone(),
        deep.clone(),
    ])
    .unwrap();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: deep.uid.to_string(),
        parent_uid: Some(removed.uid.to_string()),
        name: Some(deep.name.clone()),
        blob_path: Some("/staging/foreign".into()),
        meta_json: Some("{}".into()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();

    let removed_uids = db
        .publish_foreign_children(&shared.uid, std::slice::from_ref(&kept.uid), &[])
        .unwrap();
    assert_eq!(removed_uids, vec![removed.uid.clone()]);
    let snapshot = db.visible_children(&shared.uid).unwrap();
    assert_eq!(snapshot.len(), 1);
    assert_eq!(snapshot[0].uid, kept.uid);
    assert!(
        db.node_by_uid(&deep.uid.to_string())
            .unwrap()
            .unwrap()
            .trashed
    );
    assert!(db.search("secret", 10).unwrap().is_empty());
    assert_eq!(db.pending_ops().unwrap().len(), 1);
    assert_eq!(
        db.children_if_listed(&shared.uid).unwrap().unwrap().len(),
        1,
        "restart hydration sees the completed authoritative snapshot"
    );
}

#[test]
fn foreign_delete_tombstones_the_subtree_without_losing_pending_work() {
    let db = Db::open_in_memory().unwrap();
    let own_root = folder("root", None, "My Files");
    let virtual_uid = NodeUid::new(VolumeId::from("virtual"), LinkId::from("sharedwithme"));
    let virtual_root = foreign_folder(
        "virtual",
        "sharedwithme",
        own_root.uid.clone(),
        "Shared with me",
    );
    let shared = foreign_folder("foreign", "share", virtual_uid, "Shared");
    let deleted = foreign_folder("foreign", "deleted", shared.uid.clone(), "Deleted");
    let deep = foreign_folder("foreign", "deep", deleted.uid.clone(), "Searchable deep");
    db.upsert_nodes(&[
        own_root,
        virtual_root,
        shared,
        deleted.clone(),
        deep.clone(),
    ])
    .unwrap();
    db.set_share_access(&deleted.uid, crate::Access::Editor)
        .unwrap();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: deep.uid.to_string(),
        parent_uid: Some(deleted.uid.to_string()),
        name: Some(deep.name.clone()),
        blob_path: Some("/staging/deleted-foreign".to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();
    assert_eq!(db.search("Searchable", 10).unwrap().len(), 1);

    db.tombstone_foreign_subtree(&deleted.uid).unwrap();

    for uid in [&deleted.uid, &deep.uid] {
        assert!(db.node_by_uid(&uid.to_string()).unwrap().unwrap().trashed);
    }
    assert!(db.search("Searchable", 10).unwrap().is_empty());
    assert_eq!(db.pending_ops().unwrap().len(), 1);
    assert_eq!(
        db.share_access(&deleted.uid).unwrap(),
        Some(crate::Access::Viewer)
    );
}

#[test]
fn hidden_virtual_root_removes_descendants_from_fts_and_restores_them() {
    let db = Db::open_in_memory().unwrap();
    let own_root = folder("root", None, "My Files");
    let virtual_uid = NodeUid::new(VolumeId::from("virtual"), LinkId::from("sharedwithme"));
    let mut virtual_root = foreign_folder(
        "virtual",
        "sharedwithme",
        own_root.uid.clone(),
        "Shared with me",
    );
    let shared = foreign_folder("foreign", "share", virtual_uid, "Shared");
    let child = foreign_folder(
        "foreign",
        "child",
        shared.uid.clone(),
        "Findable descendant",
    );
    db.upsert_node(&own_root).unwrap();
    assert!(
        db.publish_virtual_root("shared_with_me_name", &virtual_root)
            .unwrap()
    );
    db.upsert_nodes(&[shared, child.clone()]).unwrap();
    assert_eq!(db.search("Findable", 10).unwrap().len(), 1);

    virtual_root.trashed = true;
    assert!(
        db.publish_virtual_root("shared_with_me_name", &virtual_root)
            .unwrap()
    );
    assert!(db.search("Findable", 10).unwrap().is_empty());
    assert!(
        !db.node_by_uid(&child.uid.to_string())
            .unwrap()
            .unwrap()
            .trashed,
        "valid descendants are hidden by ancestry, not revoked"
    );

    virtual_root.trashed = false;
    assert!(
        db.publish_virtual_root("shared_with_me_name", &virtual_root)
            .unwrap()
    );
    assert_eq!(db.search("Findable", 10).unwrap().len(), 1);
    let before = db.with_conn(|conn| Ok(conn.total_changes())).unwrap();
    assert!(
        !db.publish_virtual_root("shared_with_me_name", &virtual_root)
            .unwrap()
    );
    let after = db.with_conn(|conn| Ok(conn.total_changes())).unwrap();
    assert_eq!(
        before, after,
        "unchanged root lookup performs no DB/FTS writes"
    );
}

#[test]
fn shared_root_pinned_name_survives_database_reopen() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-shared-name-{}-{}.db",
        std::process::id(),
        now_test_id()
    ));
    {
        let db = Db::open(&path).unwrap();
        db.set_state_str("shared_with_me_name", "Shared with me (Proton 4)")
            .unwrap();
    }
    let reopened = Db::open(&path).unwrap();
    assert_eq!(
        reopened
            .state_str("shared_with_me_name")
            .unwrap()
            .as_deref(),
        Some("Shared with me (Proton 4)")
    );
    drop(reopened);
    let _ = std::fs::remove_file(path);
}

/// Two writers on one database is the failure mode the single-instance lock
/// exists to prevent — a hand-run `pdfs mount` next to the systemd unit gives
/// two daemons the same inode space, content cache, and drain queue. The second
/// open has to fail, and it has to stop failing once the first handle is gone.
#[test]
fn a_second_writer_is_refused_while_the_first_holds_the_database() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-single-writer-{}-{}.db",
        std::process::id(),
        now_test_id()
    ));
    let first = Db::open(&path).unwrap();
    let second = Db::open(&path);
    assert!(second.is_err(), "a second writer was allowed in");

    drop(first);
    // The lock lives in the kernel and dies with the descriptor, so nothing has
    // to be cleaned up for the next daemon to start.
    Db::open(&path).expect("reopen after the first handle is dropped");

    let _ = std::fs::remove_file(&path);
    let _ = std::fs::remove_file(path.with_extension("db.lock"));
}

/// `cache.db` is derived state — every row can be re-fetched or re-scanned — so
/// a file that is not a database at all must not stop the daemon starting. It
/// is moved aside (not deleted: it is the only evidence) and rebuilt.
#[test]
fn a_corrupt_database_is_moved_aside_and_rebuilt() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-corrupt-{}-{}.db",
        std::process::id(),
        now_test_id()
    ));
    std::fs::write(&path, b"this is not an SQLite database").unwrap();

    let db = Db::open(&path).unwrap();
    db.set_state_str("shared_with_me_name", "rebuilt").unwrap();
    assert_eq!(
        db.state_str("shared_with_me_name").unwrap().as_deref(),
        Some("rebuilt")
    );
    drop(db);

    let dir = path.parent().unwrap();
    let stem = path.file_name().unwrap().to_string_lossy().to_string();
    let quarantined: Vec<_> = std::fs::read_dir(dir)
        .unwrap()
        .filter_map(|e| e.ok())
        .map(|e| e.file_name().to_string_lossy().to_string())
        .filter(|name| name.starts_with(&format!("{stem}.corrupt-")))
        .collect();
    assert_eq!(quarantined.len(), 1, "the damaged file was not kept");

    for name in quarantined {
        let _ = std::fs::remove_file(dir.join(name));
    }
    let _ = std::fs::remove_file(&path);
    let _ = std::fs::remove_file(path.with_extension("db.lock"));
}

/// A rebuilt database must not lose what only this machine has: writes Drive
/// has not received, the mirror baselines and the pins (`docs/BUGS.md` B216).
#[test]
fn a_rebuild_keeps_the_queue_baselines_and_pins_of_the_damaged_file() {
    let id = now_test_id();
    let damaged =
        std::env::temp_dir().join(format!("pdfs-salvage-old-{}-{id}.db", std::process::id()));
    let fresh =
        std::env::temp_dir().join(format!("pdfs-salvage-new-{}-{id}.db", std::process::id()));

    let db = Db::open(&damaged).unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&file("listed", "root", "listed.txt", 1))
        .unwrap();
    db.upsert_node(&file("queued", "root", "queued.txt", 2))
        .unwrap();
    db.set_listed(&uid("root"), true).unwrap();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: uid("queued").to_string(),
        parent_uid: None,
        name: None,
        blob_path: Some("/staging/queued".into()),
        meta_json: None,
        created_at: 1,
        attempts: 3,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();
    let folder_id = db
        .sync_folder_add("/home/me/Docs", "vol~docs", "share")
        .unwrap();
    db.sync_entry_upsert(
        folder_id,
        &StoredSyncEntry {
            rel_path: "a.txt".into(),
            remote_uid: Some("vol~a".into()),
            local_mtime: 5,
            local_mtime_ns: None,
            local_size: 6,
            remote_rev: Some("7".into()),
            remote_hash: Some("8".into()),
            remote_revision_id: None,
        },
    )
    .unwrap();
    db.pin_add("vol~pinned", "/pinned", true).unwrap();
    drop(db);

    let db = Db::open(&fresh).unwrap();
    let results = salvage(&db.conn.lock(), &damaged);
    assert!(results.iter().all(|(_, r)| r.is_ok()), "{results:?}");

    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!(ops[0].uid, uid("queued").to_string());
    assert_eq!(ops[0].blob_path.as_deref(), Some("/staging/queued"));
    // The op's node came with it; the rest of the tree is fetched again.
    assert!(
        db.node_by_uid(&uid("queued").to_string())
            .unwrap()
            .is_some()
    );
    assert!(
        db.node_by_uid(&uid("listed").to_string())
            .unwrap()
            .is_none()
    );
    assert_eq!(db.sync_entries(folder_id).unwrap().len(), 1);
    assert!(db.is_pinned("vol~pinned").unwrap());
    drop(db);

    for path in [&damaged, &fresh] {
        for suffix in ["", "-wal", "-shm"] {
            let mut file = path.as_os_str().to_owned();
            file.push(suffix);
            let _ = std::fs::remove_file(std::path::PathBuf::from(file));
        }
        let _ = std::fs::remove_file(path.with_extension("db.lock"));
    }
}

fn local(path: &str, name: &str, is_dir: bool) -> LocalEntry {
    LocalEntry {
        path: path.into(),
        name: name.into(),
        is_dir,
        size: 10,
        mtime: 5,
    }
}

/// A local scan is searchable by substring, and a *later* scan prunes the
/// paths it no longer sees — including out of the FTS index, so a deleted
/// file cannot keep surfacing in the prompt.
#[test]
fn local_scan_indexes_then_prunes_stale_paths() {
    let db = Db::open_in_memory().unwrap();

    let gen1 = db.local_begin_scan().unwrap();
    db.local_upsert_batch(
        gen1,
        &[
            local("/home/u/docs/report.pdf", "report.pdf", false),
            local("/home/u/docs/notes.md", "notes.md", false),
        ],
    )
    .unwrap();
    assert_eq!(db.local_finish_scan(gen1, 1_000).unwrap(), 2);

    // Trigram index gives substring (not just prefix) matches.
    let hits = db.search_local("port", 10).unwrap();
    assert_eq!(hits.len(), 1);
    assert_eq!(hits[0].path, "/home/u/docs/report.pdf");
    assert!(!hits[0].is_dir);
    assert_eq!(db.local_indexed_at().unwrap(), Some(1_000));

    // Second scan sees only notes.md → report.pdf is gone from disk.
    let gen2 = db.local_begin_scan().unwrap();
    db.local_upsert_batch(gen2, &[local("/home/u/docs/notes.md", "notes.md", false)])
        .unwrap();
    assert_eq!(db.local_finish_scan(gen2, 2_000).unwrap(), 1);
    assert!(db.search_local("report", 10).unwrap().is_empty());
    assert_eq!(db.search_local("notes", 10).unwrap().len(), 1);
}

/// The index is maintained incrementally rather than rebuilt at the end of a
/// scan, so the case that used to be covered for free — a file the scan sees
/// again — needs its own test: a re-scan must neither lose the entry nor
/// duplicate it.
#[test]
fn rescanning_an_unchanged_file_keeps_exactly_one_index_entry() {
    let db = Db::open_in_memory().unwrap();
    for (generation, mtime) in [(1_000, 5), (2_000, 9)] {
        let g = db.local_begin_scan().unwrap();
        let mut e = local("/home/u/docs/report.pdf", "report.pdf", false);
        e.mtime = mtime;
        db.local_upsert_batch(g, &[e]).unwrap();
        assert_eq!(db.local_finish_scan(g, generation).unwrap(), 1);
        let hits = db.search_local("report", 10).unwrap();
        assert_eq!(hits.len(), 1, "generation {generation}");
        assert_eq!(hits[0].mtime, mtime);
    }
}

/// A scan that stopped early or lost a batch did not see every file, so it
/// must not prune the ones it missed (`docs/BUGS.md` B217).
#[test]
fn a_partial_local_scan_prunes_nothing() {
    let db = Db::open_in_memory().unwrap();
    let g = db.local_begin_scan().unwrap();
    db.local_upsert_batch(
        g,
        &[
            local("/home/u/a.txt", "a.txt", false),
            local("/home/u/b.txt", "b.txt", false),
        ],
    )
    .unwrap();
    assert_eq!(db.local_finish_scan(g, 1).unwrap(), 2);

    let g = db.local_begin_scan().unwrap();
    db.local_upsert_batch(g, &[local("/home/u/a.txt", "a.txt", false)])
        .unwrap();
    assert_eq!(db.local_finish_partial_scan(2).unwrap(), 2);
    assert_eq!(db.search_local("b.txt", 10).unwrap().len(), 1);
    assert_eq!(db.local_indexed_at().unwrap(), Some(2));
}

/// Deleted entries pile up in an FTS5 index until it is compacted. The daily
/// compaction must leave both indexes whole and searchable, and must not run
/// again the same day (`docs/BUGS.md` B217).
#[test]
fn compacting_the_search_indexes_keeps_them_whole_and_runs_once_a_day() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&file("f1", "root", "quarterly-report.pdf", 1))
        .unwrap();
    for round in 0..20 {
        let g = db.local_begin_scan().unwrap();
        let name = format!("churn-{round}.txt");
        db.local_upsert_batch(
            g,
            &[
                local("/home/u/keep.txt", "keep.txt", false),
                local(&format!("/home/u/{name}"), &name, false),
            ],
        )
        .unwrap();
        // Far in the past, so no scan compacts on its own.
        db.local_finish_scan(g, 0).unwrap();
    }

    let day = 24 * 60 * 60;
    db.compact_search_indexes_if_due(day).unwrap();
    {
        let conn = db.conn.lock();
        for table in ["local_fts", "nodes_fts"] {
            conn.execute(
                &format!("INSERT INTO {table}({table}) VALUES('integrity-check')"),
                [],
            )
            .unwrap();
        }
    }
    assert_eq!(db.search_local("keep", 10).unwrap().len(), 1);
    assert_eq!(db.search_local("churn-19", 10).unwrap().len(), 1);
    assert!(db.search_local("churn-3.txt", 10).unwrap().is_empty());
    assert_eq!(db.search("quarterly", 10).unwrap().len(), 1);
    let stamp = |db: &Db| db.state_str("fts_compacted_at").unwrap();
    assert_eq!(stamp(&db).as_deref(), Some(day.to_string().as_str()));

    db.compact_search_indexes_if_due(day + 60).unwrap();
    assert_eq!(stamp(&db).as_deref(), Some(day.to_string().as_str()));
}

/// Queries below the trigram minimum still match, via the `LIKE` fallback.
#[test]
fn local_search_short_query_like_fallback() {
    let db = Db::open_in_memory().unwrap();
    let g = db.local_begin_scan().unwrap();
    db.local_upsert_batch(g, &[local("/home/u/a.txt", "a.txt", false)])
        .unwrap();
    db.local_finish_scan(g, 1).unwrap();
    assert_eq!(db.search_local("a", 10).unwrap().len(), 1);
    assert!(db.search_local("", 10).unwrap().is_empty());
}

#[test]
fn event_cursor_roundtrip() {
    let db = Db::open_in_memory().unwrap();
    // Absent before first write → seed from server head on first mount.
    assert!(db.get_event_cursor().unwrap().is_none());
    db.set_event_cursor("evt-1").unwrap();
    assert_eq!(db.get_event_cursor().unwrap().as_deref(), Some("evt-1"));
    // Overwrites, not appends.
    db.set_event_cursor("evt-2").unwrap();
    assert_eq!(db.get_event_cursor().unwrap().as_deref(), Some("evt-2"));
}

#[test]
fn search_trigram_substring_and_path() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("docs", Some("root"), "Documents"))
        .unwrap();
    db.upsert_node(&file("f1", "docs", "report.pdf", 1))
        .unwrap();
    db.upsert_node(&file("f2", "root", "notes.txt", 2)).unwrap();
    db.upsert_node(&file(
        "f3",
        "root",
        "Rampage Open Air 2026 - order 166765244.pdf",
        3,
    ))
    .unwrap();

    // Substring match (trigram), not just prefix.
    let hits = db.search("port", 10).unwrap();
    assert_eq!(hits.len(), 1);
    assert_eq!(hits[0].node.name, "report.pdf");
    // Path is mountpoint-relative, root excluded.
    assert_eq!(hits[0].path, "Documents/report.pdf");

    // Top-level file → bare name.
    let hits = db.search("notes", 10).unwrap();
    assert_eq!(hits[0].path, "notes.txt");

    // Multi-term FTS5 query matching (out of order, separated terms)
    let hits = db.search("rampage 2026", 10).unwrap();
    assert_eq!(hits.len(), 1);
    assert_eq!(
        hits[0].node.name,
        "Rampage Open Air 2026 - order 166765244.pdf"
    );
}

#[test]
fn search_in_scope_only_returns_hits_below_the_folder() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("work", Some("root"), "Work"))
        .unwrap();
    db.upsert_node(&folder("sub", Some("work"), "Old")).unwrap();
    db.upsert_node(&folder("work2", Some("root"), "Work 2"))
        .unwrap();
    db.upsert_node(&file("f1", "work", "report.pdf", 1))
        .unwrap();
    db.upsert_node(&file("f2", "sub", "report-2019.pdf", 1))
        .unwrap();
    db.upsert_node(&file("f3", "work2", "report-copy.pdf", 1))
        .unwrap();
    db.upsert_node(&file("f4", "root", "report-top.pdf", 1))
        .unwrap();

    let mut paths: Vec<String> = db
        .search_in("report", 10, Some("Work"))
        .unwrap()
        .into_iter()
        .map(|h| h.path)
        .collect();
    paths.sort();
    // A sibling whose name starts with the scope is not inside it.
    assert_eq!(paths, vec!["Work/Old/report-2019.pdf", "Work/report.pdf"]);
    // Short queries take the LIKE path and scope the same way.
    assert_eq!(db.search_in("re", 10, Some("Work/Old")).unwrap().len(), 1);
    // No scope, or the root, is everywhere.
    assert_eq!(db.search_in("report", 10, None).unwrap().len(), 4);
    assert_eq!(db.search_in("report", 10, Some("")).unwrap().len(), 4);
}

#[test]
fn search_excludes_trashed_and_respects_limit() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&file("f1", "root", "alpha.txt", 1)).unwrap();
    let mut gone = file("f2", "root", "alphb.txt", 1);
    gone.trashed = true;
    db.upsert_node(&gone).unwrap();

    let hits = db.search("alph", 10).unwrap();
    assert_eq!(hits.len(), 1);
    assert_eq!(hits[0].node.name, "alpha.txt");

    db.upsert_node(&file("f3", "root", "alphc.txt", 1)).unwrap();
    assert_eq!(db.search("alph", 1).unwrap().len(), 1);
}

/// A device folder's root is stored in `device`/`sync_folder`, never in
/// `nodes`, so its children's `parent_uid` points at a row that does not exist.
/// Requiring the ancestor walk to reach a `parent_uid IS NULL` row therefore
/// excluded every device-folder subtree from search: 2,705 of 9,252 nodes on
/// the account this was found on, including everything under `~/Downloads`.
#[test]
fn search_finds_nodes_below_an_uncached_parent() {
    let db = Db::open_in_memory().unwrap();
    // "device-root" is deliberately never upserted.
    db.upsert_node(&folder("downloads", Some("device-root"), "Downloads"))
        .unwrap();
    db.upsert_node(&file("t", "downloads", "tickets.pdf", 1))
        .unwrap();

    let hits = db.search("tickets", 10).unwrap();
    assert_eq!(hits.len(), 1, "a device folder's files must be searchable");
    assert_eq!(hits[0].path, "Downloads/tickets.pdf");
}

/// The relaxed rule must not also start indexing trash: a node whose *parent*
/// is trashed stays out even though the walk now terminates happily.
#[test]
fn search_excludes_a_node_under_a_trashed_ancestor() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    let mut folder_gone = folder("boxed", Some("root"), "Boxed");
    folder_gone.trashed = true;
    db.upsert_node(&folder_gone).unwrap();
    db.upsert_node(&file("f1", "boxed", "buried.txt", 1))
        .unwrap();

    assert!(db.search("buried", 10).unwrap().is_empty());
}

/// A parent cycle is corrupt data the API can still hand us. It must stay out
/// of the index, and — because the short-query `LIKE` lane reads `nodes`
/// directly and never consults the index — resolving one's path must terminate
/// rather than spin inside the daemon's only SQLite connection.
#[test]
fn a_parent_cycle_is_unindexed_and_never_hangs_a_search() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("a", Some("b"), "Alphaville"))
        .unwrap();
    db.upsert_node(&folder("b", Some("a"), "Betamax")).unwrap();

    // Index lane: the cycle is not indexed, so it cannot be found.
    assert!(db.search("alphaville", 10).unwrap().is_empty());
    assert!(db.search("betamax", 10).unwrap().is_empty());

    // LIKE lane (below the trigram minimum): the rows are reachable, and what
    // matters is that resolving their paths returns at all.
    let hits = db.search("al", 10).unwrap();
    assert_eq!(hits.len(), 1);
    assert!(hits[0].path.ends_with("Alphaville"));
}

#[test]
fn search_short_query_like_fallback() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&file("f1", "root", "ab.txt", 1)).unwrap();
    // Under trigram min length → LIKE path still finds it.
    let hits = db.search("ab", 10).unwrap();
    assert_eq!(hits.len(), 1);
    assert_eq!(hits[0].node.name, "ab.txt");
}

#[test]
fn fuzzy_candidates_include_typo_and_parent_path_matches() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("projects", Some("root"), "Projects"))
        .unwrap();
    db.upsert_node(&file("report", "projects", "quarterly-report.pdf", 1))
        .unwrap();
    db.upsert_node(&file("video", "projects", "video.mp4", 1))
        .unwrap();

    let typo = db.search_candidates("quartrly", 20).unwrap();
    assert!(
        typo.iter()
            .any(|hit| hit.node.name == "quarterly-report.pdf")
    );
    assert!(
        db.search_candidates("vedio", 20)
            .unwrap()
            .iter()
            .any(|hit| hit.node.name == "video.mp4")
    );

    let path = db.search_candidates("projects", 20).unwrap();
    assert!(
        path.iter()
            .any(|hit| hit.node.name == "quarterly-report.pdf")
    );
}

#[test]
fn renaming_parent_refreshes_descendant_search_paths() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("folder", Some("root"), "zzbeforezz"))
        .unwrap();
    db.upsert_node(&file("child", "folder", "plain.txt", 1))
        .unwrap();
    assert!(
        db.search_candidates("zzbeforezz", 20)
            .unwrap()
            .iter()
            .any(|h| h.node.name == "plain.txt")
    );

    db.upsert_node(&folder("folder", Some("root"), "yyafteryy"))
        .unwrap();
    assert!(
        !db.search_candidates("zzbeforezz", 20)
            .unwrap()
            .iter()
            .any(|h| h.node.name == "plain.txt")
    );
    assert!(
        db.search_candidates("yyafteryy", 20)
            .unwrap()
            .iter()
            .any(|h| h.node.name == "plain.txt")
    );
}

#[test]
fn local_fuzzy_candidates_include_typo_and_parent_path() {
    let db = Db::open_in_memory().unwrap();
    let generation = db.local_begin_scan().unwrap();
    db.local_upsert_batch(
        generation,
        &[
            local(
                "/home/u/Projects/quarterly-report.pdf",
                "quarterly-report.pdf",
                false,
            ),
            local("/home/u/Videos/video.mp4", "video.mp4", false),
        ],
    )
    .unwrap();
    db.local_finish_scan(generation, 1).unwrap();

    assert_eq!(db.search_local_candidates("quartrly", 20).unwrap().len(), 1);
    assert_eq!(db.search_local_candidates("projects", 20).unwrap().len(), 1);
    assert!(
        db.search_local_candidates("vedio", 20)
            .unwrap()
            .iter()
            .any(|hit| hit.name == "video.mp4")
    );
}

#[test]
fn search_drops_fts_row_on_delete_and_trash() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&file("f1", "root", "unique.txt", 1))
        .unwrap();
    assert_eq!(db.search("unique", 10).unwrap().len(), 1);

    // Re-upsert as trashed → leaves the index.
    let mut t = file("f1", "root", "unique.txt", 1);
    t.trashed = true;
    db.upsert_node(&t).unwrap();
    assert_eq!(db.search("unique", 10).unwrap().len(), 0);

    // Resurrect, then hard-delete.
    db.upsert_node(&file("f1", "root", "unique.txt", 1))
        .unwrap();
    assert_eq!(db.search("unique", 10).unwrap().len(), 1);
    db.delete_node(&uid("f1")).unwrap();
    assert_eq!(db.search("unique", 10).unwrap().len(), 0);
}

/// Renaming re-indexes the node, which is the case delete-by-rowid has to get
/// right: the *old* name must leave the index. A stale row here would be
/// invisible in every other test — the new name is findable either way.
#[test]
fn renaming_a_node_replaces_the_name_in_the_search_index() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&file("f1", "root", "beforename.txt", 1))
        .unwrap();
    assert_eq!(db.search("beforename", 10).unwrap().len(), 1);

    db.upsert_node(&file("f1", "root", "aftername.txt", 1))
        .unwrap();

    assert_eq!(
        db.search("aftername", 10).unwrap().len(),
        1,
        "the new name must be searchable"
    );
    assert_eq!(
        db.search("beforename", 10).unwrap().len(),
        0,
        "the old name must have left the index, not merely been added alongside"
    );
}

/// B12: the cost of writing a listing must not scale with how much is already
/// indexed. The old `DELETE FROM nodes_fts WHERE uid = ?` scanned the whole
/// index once per node written, so a large account paid more to write the *same*
/// folder — measured at 6.5 ms per node against a 17k-node index on the live DB.
///
/// Written as a ratio between two index sizes rather than an absolute time, so
/// it fails on the scaling regression and not on a slow machine.
#[test]
fn writing_nodes_does_not_scale_with_the_size_of_the_index() {
    use std::time::Instant;

    /// Fill `db` with `n` indexed nodes, then time re-writing a fixed batch.
    fn cost_against_index_of(n: usize) -> std::time::Duration {
        let db = Db::open_in_memory().unwrap();
        db.upsert_node(&folder("root", None, "My Files")).unwrap();
        let filler: Vec<_> = (0..n)
            .map(|i| file(&format!("bg{i}"), "root", &format!("background{i}.txt"), 1))
            .collect();
        db.upsert_nodes(&filler).unwrap();

        // The batch under test is identical in both runs; only the amount of
        // already-indexed data around it differs.
        let batch: Vec<_> = (0..200)
            .map(|i| file(&format!("m{i}"), "root", &format!("measured{i}.txt"), 1))
            .collect();
        db.upsert_nodes(&batch).unwrap();

        // The fastest of a few runs: the rest of the suite runs alongside, and
        // one run that lost the CPU to it read as the regression.
        (0..5)
            .map(|_| {
                let t = Instant::now();
                db.upsert_nodes(&batch).unwrap();
                t.elapsed()
            })
            .min()
            .unwrap()
    }

    let small = cost_against_index_of(200);
    let large = cost_against_index_of(5000);

    // Calibration, measured while writing this: over the same 25× growth in
    // index size, the old full-scan path cost 6.4× more (46 ms → 294 ms) while
    // the rowid path costs 1.04× (39 ms → 41 ms). 3× sits well clear of both.
    println!("B12: 200-node write — against 200 indexed {small:?}, against 5000 {large:?}");
    assert!(
        large < small * 3,
        "writing a listing got dramatically more expensive as the index grew, \
         which is the B12 full-scan regression; small={small:?} large={large:?}"
    );
}

fn activity(target: &str, kind: ActivityKind, ok: bool) -> ActivityEntry {
    ActivityEntry {
        time: 1700,
        kind,
        target: target.into(),
        detail: "detail".into(),
        ok,
    }
}

#[test]
fn activity_reads_back_newest_first() {
    let db = Db::open_in_memory().unwrap();
    db.activity_add(&activity("a.txt", ActivityKind::Upload, true))
        .unwrap();
    db.activity_add(&activity("b.txt", ActivityKind::Download, false))
        .unwrap();

    let items = db.activity_list(10).unwrap();
    assert_eq!(items.len(), 2);
    assert_eq!(items[0].target, "b.txt");
    assert_eq!(items[0].kind, ActivityKind::Download);
    assert!(!items[0].ok);
    assert_eq!(items[0].detail, "detail");
    assert_eq!(items[0].time, 1700);
    assert_eq!(items[1].target, "a.txt");

    assert_eq!(db.activity_list(1).unwrap().len(), 1);
}

#[test]
fn activity_has_finds_only_matching_kind_and_target() {
    let db = Db::open_in_memory().unwrap();
    db.activity_add(&activity(
        "a (sync-conflict 1).txt",
        ActivityKind::Conflict,
        false,
    ))
    .unwrap();
    db.activity_add(&activity("b.txt", ActivityKind::Upload, true))
        .unwrap();

    assert!(
        db.activity_has(ActivityKind::Conflict, "a (sync-conflict 1).txt")
            .unwrap()
    );
    assert!(
        !db.activity_has(ActivityKind::Upload, "a (sync-conflict 1).txt")
            .unwrap()
    );
    assert!(!db.activity_has(ActivityKind::Conflict, "b.txt").unwrap());
}

#[test]
fn activity_prunes_to_the_keep_limit() {
    let db = Db::open_in_memory().unwrap();
    for i in 0..(ACTIVITY_KEEP + 10) {
        db.activity_add(&activity(&format!("f{i}"), ActivityKind::Upload, true))
            .unwrap();
    }
    let items = db.activity_list(ACTIVITY_KEEP as usize * 2).unwrap();
    assert_eq!(items.len(), ACTIVITY_KEEP as usize);
    // The newest survive; the oldest are the ones dropped.
    assert_eq!(items[0].target, format!("f{}", ACTIVITY_KEEP + 9));
}

#[test]
fn opens_and_migrates() {
    let db = Db::open_in_memory().unwrap();
    let version: String = db
        .with_conn(|c| {
            Ok(c.query_row(
                "SELECT value FROM sync_state WHERE key = 'schema_version'",
                [],
                |r| r.get(0),
            )?)
        })
        .unwrap();
    assert_eq!(version, SCHEMA_VERSION.to_string());
}

#[test]
fn share_access_round_trips_updates_and_deletes() {
    let db = Db::open_in_memory().unwrap();
    let root = uid("shared-root");

    assert_eq!(db.share_access(&root).unwrap(), None);
    for access in [
        crate::Access::Owner,
        crate::Access::Editor,
        crate::Access::Viewer,
        crate::Access::Unknown,
    ] {
        db.set_share_access(&root, access).unwrap();
        assert_eq!(db.share_access(&root).unwrap(), Some(access));
        assert_eq!(db.all_share_access().unwrap().get(&root), Some(&access));
    }
    db.delete_share_access(&root).unwrap();
    assert_eq!(db.share_access(&root).unwrap(), None);
    assert!(db.all_share_access().unwrap().is_empty());
}

#[test]
fn effective_node_access_inherits_from_the_persisted_share_root() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("shared", Some("root"), "Shared"))
        .unwrap();
    db.upsert_node(&folder("nested", Some("shared"), "Nested"))
        .unwrap();
    db.upsert_node(&file("child", "nested", "child.txt", 1))
        .unwrap();
    db.set_share_access(&uid("shared"), crate::Access::Viewer)
        .unwrap();

    assert_eq!(
        db.effective_node_access(&uid("child")).unwrap(),
        Some(crate::Access::Viewer)
    );
    assert_eq!(
        db.effective_node_access(&uid("root")).unwrap(),
        Some(crate::Access::Owner)
    );
    assert_eq!(db.effective_node_access(&uid("missing")).unwrap(), None);
}

#[test]
fn effective_node_access_uses_the_nearest_nested_share_root() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("outer", Some("root"), "Outer"))
        .unwrap();
    db.upsert_node(&folder("inner", Some("outer"), "Inner"))
        .unwrap();
    db.upsert_node(&file("child", "inner", "child.txt", 1))
        .unwrap();
    db.set_share_access(&uid("outer"), crate::Access::Editor)
        .unwrap();
    db.set_share_access(&uid("inner"), crate::Access::Viewer)
        .unwrap();

    assert_eq!(
        db.effective_node_access(&uid("child")).unwrap(),
        Some(crate::Access::Viewer)
    );
}

#[test]
fn effective_node_access_keeps_a_missing_share_root_tombstone_authoritative() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("shared", Some("root"), "Shared"))
        .unwrap();
    db.upsert_node(&folder("nested", Some("shared"), "Nested"))
        .unwrap();
    db.upsert_node(&file("child", "nested", "child.txt", 1))
        .unwrap();
    db.set_share_access(&uid("shared"), crate::Access::Viewer)
        .unwrap();
    db.delete_node(&uid("shared")).unwrap();

    assert_eq!(
        db.effective_node_access(&uid("child")).unwrap(),
        Some(crate::Access::Viewer)
    );
}

#[test]
fn downgrade_all_share_access_leaves_unrecorded_owned_nodes_owned() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("shared", Some("root"), "Shared"))
        .unwrap();
    db.set_share_access(&uid("shared"), crate::Access::Editor)
        .unwrap();

    assert_eq!(db.downgrade_all_share_access().unwrap(), 1);
    assert_eq!(
        db.effective_node_access(&uid("shared")).unwrap(),
        Some(crate::Access::Viewer)
    );
    assert_eq!(
        db.effective_node_access(&uid("root")).unwrap(),
        Some(crate::Access::Owner)
    );
}

#[test]
fn migration_v17_adds_share_access_to_a_v16_fixture() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-v16-fixture-{}-{}.db",
        std::process::id(),
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos()
    ));
    {
        // Remove the later tables too, so restoring the version stamp produces
        // the exact schema a released V16 database had.
        let db = Db::open(&path).unwrap();
        db.set_state_str("fixture_value", "survives").unwrap();
    }
    {
        let conn = rusqlite::Connection::open(&path).unwrap();
        conn.execute_batch(
            "DROP TRIGGER mount_sync_folder_insert;
             DROP TABLE mount;
             DROP TABLE share_access;
             DROP TABLE album_photos;
             DROP TABLE albums;
             DROP INDEX idx_photos_favorite;
             ALTER TABLE photos DROP COLUMN favorite;
             ALTER TABLE nodes DROP COLUMN path;
             UPDATE sync_state SET value = '16' WHERE key = 'schema_version';",
        )
        .unwrap();
    }

    let db = Db::open(&path).unwrap();
    assert_eq!(
        db.state_str("fixture_value").unwrap().as_deref(),
        Some("survives")
    );
    let root = uid("offline-share");
    db.set_share_access(&root, crate::Access::Viewer).unwrap();
    assert_eq!(db.share_access(&root).unwrap(), Some(crate::Access::Viewer));
    // Migrating an old fixture always lands on head, whatever head is today.
    assert_eq!(
        db.state_str("schema_version").unwrap().as_deref(),
        Some(SCHEMA_VERSION.to_string().as_str())
    );

    drop(db);
    let _ = std::fs::remove_file(path);
}

#[test]
fn migration_v18_projects_v17_sync_folders_and_cascades_deletes() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-v17-fixture-{}-{}.db",
        std::process::id(),
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos()
    ));
    {
        // Pin the released V17 shape that V18 reads instead of deriving a
        // fixture from today's head schema and dropping newer objects.
        let conn = rusqlite::Connection::open(&path).unwrap();
        conn.execute_batch(
            "CREATE TABLE sync_state (key TEXT PRIMARY KEY, value TEXT);
             INSERT INTO sync_state VALUES ('schema_version', '17');
             INSERT INTO sync_state VALUES ('fixture_value', 'survives');
             CREATE TABLE sync_folder (
               id              INTEGER PRIMARY KEY,
               local_path      TEXT NOT NULL UNIQUE,
               remote_uid      TEXT NOT NULL,
               remote_share_id TEXT NOT NULL,
               mode            TEXT NOT NULL DEFAULT 'mirror',
               state           TEXT NOT NULL DEFAULT 'idle',
               last_sync       INTEGER NOT NULL DEFAULT 0,
               pending_mode    TEXT
             );
             CREATE TABLE sync_entry (
               folder_id   INTEGER NOT NULL,
               rel_path    TEXT NOT NULL,
               remote_uid  TEXT,
               local_mtime INTEGER NOT NULL DEFAULT 0,
               local_size  INTEGER NOT NULL DEFAULT 0,
               remote_hash TEXT,
               remote_rev  TEXT,
               PRIMARY KEY (folder_id, rel_path)
             );
             INSERT INTO sync_folder
               (id, local_path, remote_uid, remote_share_id, mode, state, last_sync)
             VALUES
               (41, '/home/me/Existing', 'vol~existing', 'share-existing',
                'ondemand', 'syncing', 123);
             -- The timeline as V17 held it: later migrations add columns to it,
             -- so a fixture without it isn't a database any release produced.
             CREATE TABLE photos (
               uid          TEXT PRIMARY KEY,
               capture_time INTEGER NOT NULL,
               name         TEXT,
               ratio        REAL,
               thumb_state  INTEGER NOT NULL DEFAULT 0,
               seq          INTEGER NOT NULL,
               media_type   TEXT,
               kind         INTEGER NOT NULL DEFAULT 0
             );
             CREATE TABLE share_access (
               root_uid TEXT PRIMARY KEY,
               access   TEXT NOT NULL
                        CHECK (access IN ('owner', 'editor', 'viewer', 'unknown'))
             );",
        )
        .unwrap();
    }

    let db = Db::open(&path).unwrap();
    let existing = 41;
    let locations = db.mount_list().unwrap();
    assert_eq!(locations.len(), 1);
    let projected = &locations[0];
    assert!(matches!(
        projected.kind,
        crate::mounts::MountKind::Device {
            sync_folder_id
        } if sync_folder_id == existing
    ));
    assert_eq!(projected.local_path, "/home/me/Existing");
    assert_eq!(projected.mode, crate::mounts::MountMode::OnDemand);
    assert_eq!(projected.state, "syncing");
    assert_eq!(projected.last_sync, 123);
    assert_eq!(
        db.state_str("fixture_value").unwrap().as_deref(),
        Some("survives")
    );

    let added = db
        .sync_folder_add("/home/me/New", "vol~new", "share-new")
        .unwrap();
    assert_eq!(db.mount_list().unwrap().len(), 2);
    assert!(db.sync_folder_remove(added).unwrap());
    assert_eq!(
        db.mount_list().unwrap().len(),
        1,
        "the V18 foreign key must remove the device projection"
    );
    // Migrating an old fixture always lands on head, whatever head is today.
    assert_eq!(
        db.state_str("schema_version").unwrap().as_deref(),
        Some(SCHEMA_VERSION.to_string().as_str())
    );

    drop(db);
    let _ = std::fs::remove_file(path);
}

#[test]
fn my_files_projection_retains_share_id_only_for_the_same_root() {
    let db = Db::open_in_memory().unwrap();
    let id = db
        .mount_upsert_my_files("/home/me/ProtonDrive", "vol~root", Some("share-main"))
        .unwrap();
    let same_id = db
        .mount_upsert_my_files("/mnt/proton", "vol~root", None)
        .unwrap();
    assert_eq!(same_id, id);
    assert_eq!(db.mount_list().unwrap()[0].root_share_id, "share-main");

    db.mount_upsert_my_files("/mnt/proton", "vol~root-new", None)
        .unwrap();

    let locations = db.mount_list().unwrap();
    assert_eq!(locations.len(), 1);
    assert!(matches!(
        locations[0].kind,
        crate::mounts::MountKind::MyFiles
    ));
    assert_eq!(locations[0].local_path, "/mnt/proton");
    assert_eq!(locations[0].root_uid, "vol~root-new");
    assert_eq!(
        locations[0].root_share_id, "",
        "a share id must never be paired with a different root uid"
    );
}

#[test]
fn my_files_share_id_repair_is_conditional_on_root_uid() {
    let db = Db::open_in_memory().unwrap();
    db.mount_upsert_my_files("/mnt/proton", "vol~root", None)
        .unwrap();

    assert!(
        !db.mount_repair_my_files_share_id("vol~stale", "share-stale")
            .unwrap()
    );
    assert_eq!(db.mount_list().unwrap()[0].root_share_id, "");

    assert!(
        db.mount_repair_my_files_share_id("vol~root", "share-current")
            .unwrap()
    );
    assert_eq!(db.mount_list().unwrap()[0].root_share_id, "share-current");
}

#[test]
fn mount_constraints_reject_malformed_kinds_and_missing_sync_folders() {
    let db = Db::open_in_memory().unwrap();
    let conn = db.conn.lock();

    assert!(
        conn.execute(
            "INSERT INTO mount (kind, local_path, root_uid)
             VALUES ('device', '/tmp/device', 'vol~device')",
            [],
        )
        .is_err(),
        "a device projection without sync_folder_id must fail its CHECK"
    );
    assert!(
        conn.execute(
            "INSERT INTO mount (kind, sync_folder_id)
             VALUES ('device', 999999)",
            [],
        )
        .is_err(),
        "a device projection cannot reference a missing sync folder"
    );
    assert!(
        conn.execute(
            "INSERT INTO mount (kind, share_root_uid, local_path, root_uid)
             VALUES ('myfiles', 'vol~shared', '/tmp/root', 'vol~root')",
            [],
        )
        .is_err(),
        "kind-specific columns must not be mixed"
    );
}

#[test]
fn deleting_a_device_projection_does_not_delete_its_sync_folder() {
    let db = Db::open_in_memory().unwrap();
    let folder_id = db
        .sync_folder_add("/home/me/Keep", "vol~keep", "share-keep")
        .unwrap();
    {
        let conn = db.conn.lock();
        assert_eq!(
            conn.execute(
                "DELETE FROM mount WHERE kind = 'device' AND sync_folder_id = ?1",
                [folder_id],
            )
            .unwrap(),
            1
        );
    }

    assert!(db.sync_folder_get(folder_id).unwrap().is_some());
    assert!(
        db.mount_list().unwrap().is_empty(),
        "the foreign key direction must not recreate or delete sync authority"
    );
}

#[test]
fn refuses_a_schema_newer_than_the_running_build() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-future-{}-{}.db",
        std::process::id(),
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos()
    ));
    let conn = rusqlite::Connection::open(&path).unwrap();
    conn.execute_batch(
        "CREATE TABLE sync_state (key TEXT PRIMARY KEY, value TEXT);
         INSERT INTO sync_state VALUES ('schema_version', '9999');",
    )
    .unwrap();
    drop(conn);

    let err = Db::open(&path)
        .err()
        .expect("future schema must fail closed");
    assert!(err.to_string().contains("newer than this build supports"));
    let conn = rusqlite::Connection::open(&path).unwrap();
    let version: String = conn
        .query_row(
            "SELECT value FROM sync_state WHERE key = 'schema_version'",
            [],
            |row| row.get(0),
        )
        .unwrap();
    assert_eq!(version, "9999", "failed open must not rewrite the database");
    drop(conn);
    let _ = std::fs::remove_file(path);
}

/// Queueing a write syncs it to disk, and leaves the writer at NORMAL after.
///
/// The op row is what makes a staged blob reachable once `close()` has
/// reported success, so its commit must survive a power loss. Everything else
/// the writer commits is metadata the next listing re-fetches, and pays only
/// NORMAL's cost.
#[test]
fn queueing_a_write_commits_at_full_sync_and_restores_normal() {
    let path = std::env::temp_dir().join(format!("pdfs-db-sync-{}.db", std::process::id()));
    let _ = std::fs::remove_file(&path);
    let db = Db::open(&path).unwrap();
    let level = |db: &Db| -> i64 {
        db.conn
            .lock()
            .query_row("PRAGMA synchronous", [], |r| r.get(0))
            .unwrap()
    };
    // 1 = NORMAL, 2 = FULL.
    assert_eq!(level(&db), 1);
    {
        let durable = db.durable().unwrap();
        let during: i64 = durable
            .query_row("PRAGMA synchronous", [], |r| r.get(0))
            .unwrap();
        assert_eq!(during, 2);
    }
    assert_eq!(level(&db), 1);

    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_TRASH.to_string(),
        uid: uid("a").to_string(),
        parent_uid: None,
        name: Some("a".to_string()),
        blob_path: None,
        meta_json: None,
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();
    assert_eq!(level(&db), 1);
    assert_eq!(db.pending_ops().unwrap().len(), 1);
    drop(db);
    for suffix in ["", "-wal", "-shm"] {
        let _ = std::fs::remove_file(format!("{}{suffix}", path.display()));
    }
}

/// A gap-filled blob is recorded as whole only while the op still holds it.
///
/// A write that closes during the drain points the row at a newer blob with
/// its own sidecar. Overwriting that sidecar with the older blob's would
/// describe bytes the row no longer holds.
#[test]
fn marking_a_blob_whole_leaves_a_newer_blob_alone() {
    let db = Db::open_in_memory().unwrap();
    let op = PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: uid("a").to_string(),
        parent_uid: None,
        name: None,
        blob_path: Some("/staging/first".to_string()),
        meta_json: Some(r#"{"complete":false}"#.to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    db.enqueue_op(&op).unwrap();
    let id = db.pending_ops().unwrap()[0].id;

    assert!(
        db.update_op_meta_for_blob(id, "/staging/first", r#"{"complete":true}"#)
            .unwrap()
    );
    assert_eq!(
        db.pending_ops().unwrap()[0].meta_json.as_deref(),
        Some(r#"{"complete":true}"#)
    );

    assert!(
        !db.update_op_meta_for_blob(id, "/staging/older", r#"{"stale":true}"#)
            .unwrap(),
        "the row holds another blob"
    );
    assert_eq!(
        db.pending_ops().unwrap()[0].meta_json.as_deref(),
        Some(r#"{"complete":true}"#)
    );
}

/// A queued write whose baseline is restamped must keep everything else.
///
/// The restamp happens after our *own* upload seals a new revision under a
/// still-queued write. If it took the blob or the retry state with it, the fix
/// for a spurious conflict copy would cost the bytes that conflict copy was
/// there to protect.
#[test]
fn restamping_a_baseline_leaves_the_blob_and_retry_state_alone() {
    let db = Db::open_in_memory().unwrap();
    let op = PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: uid("a").to_string(),
        parent_uid: None,
        name: None,
        blob_path: Some("/staging/blob".to_string()),
        meta_json: Some(r#"{"based_on":"old"}"#.to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    db.enqueue_op(&op).unwrap();
    db.record_op_failure(db.pending_ops().unwrap()[0].id, "offline", 999)
        .unwrap();

    let updated = db
        .update_op_meta(&uid("a").to_string(), OP_REVISION, r#"{"based_on":"new"}"#)
        .unwrap();
    assert!(updated, "the queued write is there to restamp");

    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!(ops[0].meta_json.as_deref(), Some(r#"{"based_on":"new"}"#));
    assert_eq!(
        ops[0].blob_path.as_deref(),
        Some("/staging/blob"),
        "the only copy of the user's bytes"
    );
    assert_eq!(ops[0].attempts, 1, "backoff survives a restamp");
    assert_eq!(ops[0].next_attempt_at, 999);

    // No queued write for that node is the ordinary case, not an error: most
    // uploads are the last one for their file.
    assert!(
        !db.update_op_meta(&uid("b").to_string(), OP_REVISION, "{}")
            .unwrap()
    );
}

#[test]
fn a_second_write_supersedes_the_first_pending_op() {
    let db = Db::open_in_memory().unwrap();
    let op = |blob: &str| PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: uid("a").to_string(),
        parent_uid: None,
        name: None,
        blob_path: Some(blob.to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };

    let (_, superseded) = db.enqueue_op(&op("/staging/first")).unwrap();
    assert_eq!(superseded, None, "nothing to supersede on the first write");

    // The newer blob already contains everything the older one did, so the
    // older op must go — and its blob must be reported so it can be deleted
    // rather than leaked.
    let (id2, superseded) = db.enqueue_op(&op("/staging/second")).unwrap();
    assert_eq!(superseded.as_deref(), Some("/staging/first"));

    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1, "one queued upload per node");
    assert_eq!(ops[0].id, id2);
    assert_eq!(ops[0].blob_path.as_deref(), Some("/staging/second"));
    assert_eq!(db.pending_op_counts().unwrap().uploads, 1);
}

#[test]
fn failed_superseding_insert_keeps_the_old_pending_op() {
    let db = Db::open_in_memory().unwrap();
    let op = |blob: &str| PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: uid("atomic").to_string(),
        parent_uid: None,
        name: None,
        blob_path: Some(blob.to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    db.enqueue_op(&op("/staging/original")).unwrap();
    db.with_conn(|conn| {
        conn.execute_batch(
            "CREATE TRIGGER reject_replacement BEFORE INSERT ON pending_op
             WHEN NEW.blob_path = '/staging/replacement'
             BEGIN SELECT RAISE(ABORT, 'injected insert failure'); END;",
        )?;
        Ok(())
    })
    .unwrap();

    assert!(db.enqueue_op(&op("/staging/replacement")).is_err());
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!(ops[0].blob_path.as_deref(), Some("/staging/original"));
}

/// B53's remaining half. The insert-failure regression above proves the *row*
/// rolls back; this proves the two things that make the rollback usable — the
/// old blob is not reported as superseded (so the caller does not delete the
/// bytes the surviving row still points at), and the rollback survives a
/// restart rather than living only in the connection that failed.
#[test]
fn a_rolled_back_supersede_keeps_its_blob_and_survives_reopen() {
    let dir = std::env::temp_dir().join(format!("pdfs-db-b53-{}", std::process::id()));
    let _ = std::fs::remove_dir_all(&dir);
    std::fs::create_dir_all(&dir).unwrap();
    let path = dir.join("queue.sqlite");
    let op = |blob: &str| PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: uid("durable").to_string(),
        parent_uid: None,
        name: None,
        blob_path: Some(blob.to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };

    {
        let db = Db::open(&path).unwrap();
        db.enqueue_op(&op("/staging/original")).unwrap();
        db.with_conn(|conn| {
            conn.execute_batch(
                "CREATE TRIGGER reject_replacement BEFORE INSERT ON pending_op
                 WHEN NEW.blob_path = '/staging/replacement'
                 BEGIN SELECT RAISE(ABORT, 'injected insert failure'); END;",
            )?;
            Ok(())
        })
        .unwrap();

        // The failure must not hand back the old blob path. That value is the
        // caller's instruction to delete those bytes, and the row that owns
        // them is still queued.
        assert!(db.enqueue_op(&op("/staging/replacement")).is_err());
        db.with_conn(|conn| {
            conn.execute_batch("DROP TRIGGER reject_replacement")?;
            Ok(())
        })
        .unwrap();
    }

    let db = Db::open(&path).unwrap();
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1, "old or new — never neither");
    assert_eq!(ops[0].blob_path.as_deref(), Some("/staging/original"));

    // And once the injected failure is gone, superseding works and *does*
    // report the blob it retired.
    let (_, superseded) = db.enqueue_op(&op("/staging/replacement")).unwrap();
    assert_eq!(superseded.as_deref(), Some("/staging/original"));
    assert_eq!(db.pending_ops().unwrap().len(), 1);

    drop(db);
    std::fs::remove_dir_all(&dir).unwrap();
}

/// A full disk, as SQLite reports it. `max_page_count` makes the database
/// refuse to grow, which is the same `SQLITE_FULL` an out-of-space filesystem
/// produces — and the queue must come out of it with the acknowledged work
/// still in it (B53).
#[test]
fn a_full_database_rolls_the_supersede_back_rather_than_erasing_it() {
    let db = Db::open_in_memory().unwrap();
    let op = |blob: &str| PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: uid("full").to_string(),
        parent_uid: None,
        name: None,
        blob_path: Some(blob.to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    db.enqueue_op(&op("/staging/original")).unwrap();

    // Cap the file at its current size, so any page the insert needs fails.
    let pages: i64 = db
        .with_conn(|conn| Ok(conn.query_row("PRAGMA page_count", [], |r| r.get(0))?))
        .unwrap();
    db.with_conn(|conn| {
        conn.execute_batch(&format!("PRAGMA max_page_count = {pages}"))?;
        Ok(())
    })
    .unwrap();

    // A payload far larger than one page, so growth is unavoidable.
    let mut fat = op("/staging/replacement");
    fat.meta_json = Some("x".repeat(512 * 1024));
    let result = db.enqueue_op(&fat);

    db.with_conn(|conn| {
        conn.execute_batch("PRAGMA max_page_count = 1073741823")?;
        Ok(())
    })
    .unwrap();

    assert!(result.is_err(), "a database that cannot grow must refuse");
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!(
        ops[0].blob_path.as_deref(),
        Some("/staging/original"),
        "the acknowledged upload is still queued and still owns its bytes"
    );
}

#[test]
fn atomic_trash_replacement_returns_owned_blobs_after_commit() {
    let db = Db::open_in_memory().unwrap();
    let root = uid("trash-root").to_string();
    let child = uid("trash-child").to_string();
    let revision = |uid: &str, parent_uid: Option<&str>, blob: &str| PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: uid.to_string(),
        parent_uid: parent_uid.map(str::to_string),
        name: None,
        blob_path: Some(blob.to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    db.enqueue_op(&revision(&root, None, "/staging/root"))
        .unwrap();
    db.enqueue_op(&revision(&child, Some(&root), "/staging/child"))
        .unwrap();

    let (trash_id, mut blobs) = db.replace_ops_with_trash(&root, "removed.txt", 2).unwrap();
    blobs.sort();
    assert_eq!(blobs, vec!["/staging/child", "/staging/root"]);

    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!(ops[0].id, trash_id);
    assert_eq!(ops[0].kind, OP_TRASH);
    assert_eq!(ops[0].uid, root);
    assert_eq!(ops[0].name.as_deref(), Some("removed.txt"));
    assert!(ops[0].blob_path.is_none());
}

#[test]
fn a_queued_trash_holds_its_name_until_it_lands() {
    let db = Db::open_in_memory().unwrap();
    let node = uid("held-name").to_string();
    assert!(!db.has_pending_trash_named("report.txt").unwrap());

    let (trash_id, _) = db.replace_ops_with_trash(&node, "report.txt", 1).unwrap();
    assert!(db.has_pending_trash_named("report.txt").unwrap());
    assert!(!db.has_pending_trash_named("other.txt").unwrap());

    db.delete_op(trash_id).unwrap();
    assert!(!db.has_pending_trash_named("report.txt").unwrap());
}

/// A create that found its name held by a queued trash backed off. The trash
/// landing frees the name, so the create is due at once instead of after the
/// backoff; a parked create stays parked.
#[test]
fn a_landed_trash_makes_the_ops_waiting_for_its_name_due() {
    let db = Db::open_in_memory().unwrap();
    let old = uid("old");
    db.upsert_node(&file("old", "root", "report.txt", 1))
        .unwrap();
    let (trash_id, _) = db
        .replace_ops_with_trash(&old.to_string(), "report.txt", 1)
        .unwrap();
    let create = |name: &str, next_attempt_at: i64| {
        let (id, _) = db
            .enqueue_op(&PendingOp {
                id: 0,
                kind: OP_CREATE.to_string(),
                uid: format!("local~{name}-{next_attempt_at}"),
                parent_uid: Some(uid("root").to_string()),
                name: Some(name.to_string()),
                blob_path: None,
                meta_json: None,
                created_at: 2,
                attempts: 0,
                last_error: None,
                next_attempt_at,
            })
            .unwrap();
        db.record_op_failure(id, "report.txt is still held", next_attempt_at)
            .unwrap();
        id
    };
    let waiting = create("report.txt", 9_000);
    let parked = create("report.txt", PARK_UNTIL);
    let other = create("other.txt", 9_000);

    db.complete_trash_op(trash_id, &old).unwrap();

    let due = |id| {
        db.pending_ops()
            .unwrap()
            .into_iter()
            .find(|op| op.id == id)
            .unwrap()
            .next_attempt_at
    };
    assert_eq!(due(waiting), 0);
    assert_eq!(due(parked), PARK_UNTIL);
    assert_eq!(due(other), 9_000);
}

#[test]
fn a_queued_rename_away_from_a_name_holds_it_until_it_lands() {
    let db = Db::open_in_memory().unwrap();
    let root = uid("root").to_string();
    let rename = |node: &str, from: &str, to: &str| {
        let meta = serde_json::to_string(&RenameMeta {
            original_parent_uid: root.clone(),
            original_name: Some(from.to_string()),
        })
        .unwrap();
        db.enqueue_op(&PendingOp {
            id: 0,
            kind: OP_RENAME.to_string(),
            uid: uid(node).to_string(),
            parent_uid: Some(root.clone()),
            name: Some(to.to_string()),
            blob_path: None,
            meta_json: Some(meta),
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap()
        .0
    };
    let away = rename("away", "c.bin", "d");
    rename("back", "e.md", "e.md");
    let (waiting, _) = db
        .enqueue_op(&PendingOp {
            id: 0,
            kind: OP_CREATE.to_string(),
            uid: "local~waiting".to_string(),
            parent_uid: Some(root.clone()),
            name: Some("c.bin".to_string()),
            blob_path: None,
            meta_json: None,
            created_at: 2,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap();
    db.record_op_failure(waiting, "c.bin is still held", 9_000)
        .unwrap();

    assert!(db.has_pending_move_from("c.bin").unwrap());
    assert!(!db.has_pending_move_from("d").unwrap());
    assert!(
        !db.has_pending_move_from("e.md").unwrap(),
        "a rename that keeps the name in its folder frees nothing"
    );
    db.wake_ops_waiting_for("c.bin").unwrap();
    let due = || {
        db.pending_ops()
            .unwrap()
            .into_iter()
            .find(|op| op.id == waiting)
            .unwrap()
            .next_attempt_at
    };
    assert_eq!(due(), 9_000, "the rename still holds the name");

    db.delete_op(away).unwrap();
    db.wake_ops_waiting_for("c.bin").unwrap();
    assert_eq!(due(), 0);
}

#[test]
fn failed_atomic_trash_insert_keeps_prior_revision_and_blob_ownership() {
    let db = Db::open_in_memory().unwrap();
    let node = uid("atomic-trash").to_string();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: node.clone(),
        parent_uid: None,
        name: None,
        blob_path: Some("/staging/still-owned".to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();
    db.with_conn(|conn| {
        conn.execute_batch(
            "CREATE TRIGGER reject_trash_insert BEFORE INSERT ON pending_op
             WHEN NEW.kind = 'trash'
             BEGIN SELECT RAISE(ABORT, 'injected trash insert failure'); END;",
        )?;
        Ok(())
    })
    .unwrap();

    assert!(db.replace_ops_with_trash(&node, "removed.txt", 2).is_err());
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!(ops[0].kind, OP_REVISION);
    assert_eq!(ops[0].uid, node);
    assert_eq!(
        ops[0].blob_path.as_deref(),
        Some("/staging/still-owned"),
        "the rolled-back revision still owns its staged bytes"
    );
}

/// Discarding a change to a node Drive has drops that node's ops and nothing
/// queued below it, and nothing at all while one of them is on the wire.
#[test]
fn discarding_a_nodes_change_keeps_what_is_queued_inside_it() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_nodes(&[
        folder("root", None, "My Files"),
        folder("dir", Some("root"), "dir"),
        file("inner", "dir", "inner.bin", 1),
    ])
    .unwrap();
    let op = |kind: &str, link: &str, blob: Option<&str>| PendingOp {
        id: 0,
        kind: kind.to_string(),
        uid: uid(link).to_string(),
        parent_uid: None,
        name: Some("renamed".to_string()),
        blob_path: blob.map(str::to_string),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    db.enqueue_op(&op(OP_RENAME, "dir", None)).unwrap();
    db.enqueue_op(&op(OP_REVISION, "inner", Some("/staging/inner")))
        .unwrap();

    let dir = uid("dir").to_string();
    assert_eq!(db.discard_ops_on_node(&dir).unwrap(), Some(vec![]));
    let left: Vec<String> = db
        .pending_ops()
        .unwrap()
        .into_iter()
        .map(|op| op.uid)
        .collect();
    assert_eq!(left, vec![uid("inner").to_string()]);

    let inner = uid("inner").to_string();
    let claimed = db.claim_next_due_op(2).unwrap().unwrap();
    assert_eq!(claimed.uid, inner);
    assert_eq!(db.discard_ops_on_node(&inner).unwrap(), None);
    assert_eq!(db.pending_ops().unwrap().len(), 1);
    db.record_op_failure(claimed.id, "no answer", 0).unwrap();
    db.release_op_claim(claimed.id).unwrap();
    assert_eq!(
        db.discard_ops_on_node(&inner).unwrap(),
        Some(vec!["/staging/inner".to_string()])
    );
    assert!(db.pending_ops().unwrap().is_empty());
}

/// A revision op names no parent, so the queue alone cannot see that its file
/// sits inside a folder being removed. The node tree can: trashing the folder
/// has to take the uploads of the files below it along, or they fail forever
/// against a trashed node and keep their bytes on disk (B102). A rename that
/// moved a node into the folder still has to land.
#[test]
fn trashing_a_folder_drops_the_queued_revisions_of_files_below_it() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_nodes(&[
        folder("root", None, "My Files"),
        folder("doomed", Some("root"), "doomed"),
        folder("sub", Some("doomed"), "sub"),
        file("deep", "sub", "deep.bin", 1),
        file("moved", "doomed", "moved.txt", 1),
        file("kept", "root", "kept.bin", 1),
    ])
    .unwrap();
    let op = |kind: &str, link: &str, blob: Option<&str>| PendingOp {
        id: 0,
        kind: kind.to_string(),
        uid: uid(link).to_string(),
        parent_uid: None,
        name: None,
        blob_path: blob.map(str::to_string),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    db.enqueue_op(&op(OP_REVISION, "deep", Some("/staging/deep")))
        .unwrap();
    db.enqueue_op(&op(OP_RENAME, "moved", None)).unwrap();
    db.enqueue_op(&op(OP_REVISION, "kept", Some("/staging/kept")))
        .unwrap();

    let doomed = uid("doomed").to_string();
    let (_, blobs) = db.replace_ops_with_trash(&doomed, "doomed", 2).unwrap();
    assert_eq!(blobs, vec!["/staging/deep"]);

    let mut left: Vec<(String, String)> = db
        .pending_ops()
        .unwrap()
        .into_iter()
        .map(|op| (op.kind, op.uid))
        .collect();
    left.sort();
    assert_eq!(
        left,
        vec![
            (OP_RENAME.to_string(), uid("moved").to_string()),
            (OP_REVISION.to_string(), uid("kept").to_string()),
            (OP_TRASH.to_string(), doomed.clone()),
        ]
    );

    // Deleting outright follows the same tree.
    db.enqueue_op(&op(OP_REVISION, "deep", Some("/staging/deep2")))
        .unwrap();
    assert_eq!(
        db.delete_ops_for_uid(&uid("sub").to_string()).unwrap(),
        vec!["/staging/deep2"]
    );
}

/// A create in a subfolder that already exists on Drive names that subfolder,
/// not the folder being trashed, as its parent. It has to go with the folder
/// all the same, along with whatever is queued inside it, or a parked one
/// keeps its bytes for good and a due one is made in the root (B116).
#[test]
fn trashing_a_folder_drops_the_queued_creates_in_its_subfolders() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_nodes(&[
        folder("root", None, "My Files"),
        folder("doomed", Some("root"), "doomed"),
        folder("sub", Some("doomed"), "sub"),
        folder("other", Some("root"), "other"),
    ])
    .unwrap();
    let op = |kind: &str, node: &str, parent: &str, blob: Option<&str>| PendingOp {
        id: 0,
        kind: kind.to_string(),
        uid: node.to_string(),
        parent_uid: Some(parent.to_string()),
        name: Some(format!("{node}.bin")),
        blob_path: blob.map(str::to_string),
        meta_json: None,
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    let sub = uid("sub").to_string();
    db.enqueue_op(&op(OP_CREATE, "local~deep", &sub, Some("/staging/deep")))
        .unwrap();
    db.enqueue_op(&op(OP_MKDIR, "local~dir", &sub, None))
        .unwrap();
    db.enqueue_op(&op(
        OP_CREATE,
        "local~deeper",
        "local~dir",
        Some("/staging/deeper"),
    ))
    .unwrap();
    db.enqueue_op(&op(
        OP_CREATE,
        "local~kept",
        &uid("other").to_string(),
        Some("/staging/kept"),
    ))
    .unwrap();

    let doomed = uid("doomed").to_string();
    let (_, mut blobs) = db.replace_ops_with_trash(&doomed, "doomed", 2).unwrap();
    blobs.sort();
    assert_eq!(blobs, vec!["/staging/deep", "/staging/deeper"]);

    let mut left: Vec<(String, String)> = db
        .pending_ops()
        .unwrap()
        .into_iter()
        .map(|op| (op.kind, op.uid))
        .collect();
    left.sort();
    assert_eq!(
        left,
        vec![
            (OP_CREATE.to_string(), "local~kept".to_string()),
            (OP_TRASH.to_string(), doomed),
        ]
    );
}

/// Deleting a folder that was created offline must take the ops queued
/// underneath it with it: they name a placeholder parent that will now never
/// become real, so nothing could ever drain them and nothing is left to
/// rewrite them.
#[test]
fn deleting_a_queued_folder_takes_its_queued_children_with_it() {
    let db = Db::open_in_memory().unwrap();
    let op = |kind: &str, uid: &str, parent: &str, blob: Option<&str>| PendingOp {
        id: 0,
        kind: kind.to_string(),
        uid: uid.to_string(),
        parent_uid: Some(parent.to_string()),
        name: Some("n".to_string()),
        blob_path: blob.map(str::to_string),
        meta_json: None,
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    let root = uid("root").to_string();
    db.enqueue_op(&op(OP_MKDIR, "local~dir", &root, None))
        .unwrap();
    db.enqueue_op(&op(OP_MKDIR, "local~sub", "local~dir", None))
        .unwrap();
    db.enqueue_op(&op(
        OP_CREATE,
        "local~deep",
        "local~sub",
        Some("/staging/deep"),
    ))
    .unwrap();
    // A sibling outside the doomed subtree must survive.
    db.enqueue_op(&op(OP_CREATE, "local~other", &root, Some("/staging/other")))
        .unwrap();

    let blobs = db.delete_ops_for_uid("local~dir").unwrap();
    assert_eq!(
        blobs,
        vec!["/staging/deep"],
        "the subtree's bytes come back"
    );

    let left: Vec<String> = db
        .pending_ops()
        .unwrap()
        .into_iter()
        .map(|o| o.uid)
        .collect();
    assert_eq!(left, vec!["local~other"]);
}

/// A rename is the node's desired end state, so the newest one is the only
/// one worth performing — but it must not disturb the queued *upload* of the
/// same node, which is unrelated work.
#[test]
fn a_second_rename_supersedes_the_first_but_leaves_the_upload_alone() {
    let db = Db::open_in_memory().unwrap();
    let rename = |name: &str| PendingOp {
        id: 0,
        kind: OP_RENAME.to_string(),
        uid: uid("a").to_string(),
        parent_uid: Some(uid("parent").to_string()),
        name: Some(name.to_string()),
        blob_path: None,
        meta_json: None,
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: uid("a").to_string(),
        parent_uid: None,
        name: None,
        blob_path: Some("/staging/blob".to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();

    db.enqueue_op(&rename("first")).unwrap();
    let (_, superseded) = db.enqueue_op(&rename("second")).unwrap();
    assert_eq!(superseded, None, "a rename owns no blob to clean up");

    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 2, "the queued upload survives the rename");
    let renames: Vec<_> = ops.iter().filter(|o| o.kind == OP_RENAME).collect();
    assert_eq!(renames.len(), 1, "one rename per node");
    assert_eq!(renames[0].name.as_deref(), Some("second"));

    let counts = db.pending_op_counts().unwrap();
    assert_eq!(counts.uploads, 1, "the revision is the only upload");
    assert_eq!(counts.changes, 1, "the rename carries no bytes");
}

/// Renaming a node whose create has not drained rewrites the intent rather
/// than queueing a rename against a uid the server has never issued.
#[test]
fn renaming_a_queued_create_rewrites_its_target() {
    let db = Db::open_in_memory().unwrap();
    let local = "local~abc";
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_CREATE.to_string(),
        uid: local.to_string(),
        parent_uid: Some(uid("old").to_string()),
        name: Some("draft.txt".to_string()),
        blob_path: Some("/staging/blob".to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();

    let rewritten = db
        .rewrite_op_target(local, &uid("new").to_string(), "final.txt")
        .unwrap();
    assert!(rewritten);

    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1, "a rewrite is not a second op");
    assert_eq!(ops[0].name.as_deref(), Some("final.txt"));
    assert_eq!(
        ops[0].parent_uid.as_deref(),
        Some(uid("new").to_string()).as_deref()
    );
    assert_eq!(
        ops[0].blob_path.as_deref(),
        Some("/staging/blob"),
        "the bytes riding on the create are untouched"
    );

    // Once the create has drained there is no intent left to rewrite, and the
    // caller has to rename the real node instead.
    db.delete_op(ops[0].id).unwrap();
    assert!(
        !db.rewrite_op_target(local, &uid("new").to_string(), "final.txt")
            .unwrap()
    );
}

/// A create that failed on a name held by a queued change waits out a
/// backoff. Renamed away from that name, it is due again at once; parked, it
/// stays parked. One whose blob a write replaced as it failed is due again at
/// once too.
#[test]
fn renaming_a_backing_off_create_makes_it_due() {
    let db = Db::open_in_memory().unwrap();
    let create = |local: &str| PendingOp {
        id: 0,
        kind: OP_CREATE.to_string(),
        uid: local.to_string(),
        parent_uid: Some(uid("dir").to_string()),
        name: Some("a.txt".to_string()),
        blob_path: Some(format!("/staging/{local}")),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    let (failed, _) = db.enqueue_op(&create("local~failed")).unwrap();
    db.record_op_failure(failed, "a.txt is still held", 10_000)
        .unwrap();
    db.enqueue_op(&create("local~parked")).unwrap();
    db.set_create_hold("local~parked", true).unwrap();

    db.rewrite_op_target("local~failed", &uid("dir").to_string(), "d")
        .unwrap();
    db.rewrite_op_target("local~parked", &uid("dir").to_string(), "e.tmp")
        .unwrap();

    let ops = db.pending_ops().unwrap();
    let op = |local: &str| ops.iter().find(|o| o.uid == local).unwrap();
    assert_eq!(op("local~failed").next_attempt_at, 0);
    assert_eq!(op("local~failed").attempts, 1);
    assert_eq!(op("local~parked").next_attempt_at, PARK_UNTIL);

    // Renamed while an attempt was on the wire, which then failed: the
    // failure is recorded after the rename, and the create is still due.
    let sent = op("local~failed").clone();
    db.rewrite_op_target("local~failed", &uid("dir").to_string(), "f")
        .unwrap();
    db.record_op_failure(sent.id, "d is still held", 10_000)
        .unwrap();
    assert!(
        db.retry_if_retargeted(
            sent.id,
            sent.parent_uid.as_deref(),
            sent.name.as_deref(),
            sent.blob_path.as_deref()
        )
        .unwrap()
    );
    let ops = db.pending_ops().unwrap();
    assert_eq!(
        ops.iter()
            .find(|o| o.id == sent.id)
            .unwrap()
            .next_attempt_at,
        0
    );
    assert!(
        !db.retry_if_retargeted(
            sent.id,
            sent.parent_uid.as_deref(),
            Some("f"),
            sent.blob_path.as_deref()
        )
        .unwrap()
    );

    // A write replaced the blob before the attempt opened it: the old one was
    // discarded, the attempt failed on a missing file, and the create is due
    // again at once with the new one (`docs/BUGS.md` B185).
    db.record_op_failure(sent.id, "No such file or directory", 10_000)
        .unwrap();
    db.attach_blob_to_create("local~failed", "/staging/newer", "{}")
        .unwrap()
        .expect("the create is still queued");
    db.record_op_failure(sent.id, "No such file or directory", 10_000)
        .unwrap();
    assert!(
        db.retry_if_retargeted(
            sent.id,
            sent.parent_uid.as_deref(),
            Some("f"),
            sent.blob_path.as_deref()
        )
        .unwrap()
    );
    assert!(
        !db.retry_if_retargeted(
            sent.id,
            sent.parent_uid.as_deref(),
            Some("f"),
            Some("/staging/newer")
        )
        .unwrap()
    );
}

/// A rename queued while an older one is on the wire waits for it. The older
/// one, if it fails, is dropped rather than retried after the newer one, also
/// when the newer one came after the failure was recorded.
#[test]
fn a_rename_on_the_wire_lands_before_the_one_that_replaces_it() {
    let db = Db::open_in_memory().unwrap();
    let file = uid("file").to_string();
    let rename = |parent: &str| PendingOp {
        id: 0,
        kind: OP_RENAME.to_string(),
        uid: file.clone(),
        parent_uid: Some(uid(parent).to_string()),
        name: Some("e.md".to_string()),
        blob_path: None,
        meta_json: None,
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    let (first, _) = db.enqueue_op(&rename("x")).unwrap();
    assert_eq!(db.claim_next_due_op(1).unwrap().unwrap().id, first);

    let (second, _) = db.enqueue_op(&rename("c0")).unwrap();
    assert!(db.claim_next_due_op(1).unwrap().is_none());

    db.record_op_failure(first, "original hash is out of date", 10_000)
        .unwrap();
    db.release_op_claim(first).unwrap();
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.iter().map(|o| o.id).collect::<Vec<_>>(), [second]);
    assert_eq!(db.claim_next_due_op(1).unwrap().unwrap().id, second);

    // Unclaimed, a queued rename is replaced as before.
    db.release_op_claim(second).unwrap();
    let (third, _) = db.enqueue_op(&rename("x")).unwrap();
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.iter().map(|o| o.id).collect::<Vec<_>>(), [third]);

    // Queued after the failure was recorded but before the claim went back:
    // the older one goes then, rather than landing after the newer (B158).
    assert_eq!(db.claim_next_due_op(1).unwrap().unwrap().id, third);
    db.record_op_failure(third, "e.md is still held", 10_000)
        .unwrap();
    let (fourth, _) = db.enqueue_op(&rename("c0")).unwrap();
    db.release_op_claim(third).unwrap();
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.iter().map(|o| o.id).collect::<Vec<_>>(), [fourth]);
}

#[test]
fn a_write_folds_into_a_queued_create_instead_of_superseding_it() {
    let db = Db::open_in_memory().unwrap();
    let local = "local~abc";
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_CREATE.to_string(),
        uid: local.to_string(),
        parent_uid: Some(uid("parent").to_string()),
        name: Some("new.txt".to_string()),
        blob_path: None,
        meta_json: None,
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();

    let first = db
        .attach_blob_to_create(local, "/staging/first", "{}")
        .unwrap()
        .expect("create is still queued");
    assert_eq!(first.superseded, None);

    // Rewriting the file before it drains replaces the bytes but must leave
    // the create itself alone: it is the only thing that will ever bring this
    // file into existence remotely.
    let second = db
        .attach_blob_to_create(local, "/staging/second", "{}")
        .unwrap()
        .expect("create is still queued");
    assert_eq!(second.superseded.as_deref(), Some("/staging/first"));

    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1, "still exactly one create");
    assert_eq!(ops[0].kind, OP_CREATE);
    assert_eq!(ops[0].blob_path.as_deref(), Some("/staging/second"));
    assert_eq!(ops[0].name.as_deref(), Some("new.txt"));
}

#[test]
fn attaching_to_an_already_drained_create_reports_it_is_gone() {
    let db = Db::open_in_memory().unwrap();
    // No create queued: the caller must fall back to a revision op rather
    // than silently dropping the bytes.
    let out = db
        .attach_blob_to_create("local~gone", "/staging/x", "{}")
        .unwrap();
    assert!(out.is_none());
}

#[test]
fn a_write_attached_while_its_create_uploads_becomes_a_revision() {
    let db = Db::open_in_memory().unwrap();
    let local = "local~abc";
    let real = uid("real").to_string();
    let parent = uid("parent").to_string();
    let create = |blob: Option<&str>| PendingOp {
        id: 0,
        kind: OP_CREATE.to_string(),
        uid: local.to_string(),
        parent_uid: Some(uid("parent").to_string()),
        name: Some("new.txt".to_string()),
        blob_path: blob.map(str::to_string),
        meta_json: blob.map(|_| "{\"uid\":\"local~abc\"}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    let (id, _) = db.enqueue_op(&create(None)).unwrap();
    // The drain picked the create up with no blob; the file's first write
    // closes while the empty upload is on the wire.
    db.attach_blob_to_create(local, "/staging/written", "{\"uid\":\"local~abc\"}")
        .unwrap()
        .expect("create is still queued");

    let newer = db
        .finish_create(
            id,
            None,
            &landing(local, &real, &parent, "new.txt"),
            |json| Some(json.replace("local~abc", "vol~real")),
        )
        .unwrap();

    assert_eq!(
        newer,
        CreateRetired::Newer {
            blob: "/staging/written".to_string(),
            meta: "{\"uid\":\"vol~real\"}".to_string()
        }
    );
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1, "the write is still queued");
    assert_eq!(ops[0].kind, OP_REVISION);
    assert_eq!(ops[0].uid, real);
    assert_eq!(ops[0].blob_path.as_deref(), Some("/staging/written"));
    assert_eq!(ops[0].parent_uid, None);
}

#[test]
fn a_create_whose_blob_landed_is_retired() {
    let db = Db::open_in_memory().unwrap();
    let local = "local~abc";
    let real = uid("real").to_string();
    let parent = uid("parent").to_string();
    let (id, _) = db
        .enqueue_op(&PendingOp {
            id: 0,
            kind: OP_CREATE.to_string(),
            uid: local.to_string(),
            parent_uid: Some(uid("parent").to_string()),
            name: Some("new.txt".to_string()),
            blob_path: Some("/staging/sent".to_string()),
            meta_json: Some("{}".to_string()),
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_CREATE.to_string(),
        uid: "local~child".to_string(),
        parent_uid: Some(local.to_string()),
        name: Some("inside.txt".to_string()),
        blob_path: None,
        meta_json: None,
        created_at: 2,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();

    let newer = db
        .finish_create(
            id,
            Some("/staging/sent"),
            &landing(local, &real, &parent, "new.txt"),
            |_| panic!("an unchanged create has no sidecar to rewrite"),
        )
        .unwrap();

    assert_eq!(newer, CreateRetired::Landed);
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1, "only the child is left");
    assert_eq!(ops[0].parent_uid.as_deref(), Some(real.as_str()));
}

/// The parent and name a create was sent with, landing where it was sent.
fn landing<'a>(local: &'a str, real: &'a str, parent: &'a str, name: &'a str) -> CreateLanding<'a> {
    CreateLanding {
        local,
        real,
        sent: (parent, name),
        landed: (parent, name),
    }
}

/// A queued op on a node made here, `kind` under `uid`.
fn op_on(kind: &str, uid: &str, parent: Option<&str>) -> PendingOp {
    PendingOp {
        id: 0,
        kind: kind.to_string(),
        uid: uid.to_string(),
        parent_uid: parent.map(str::to_string),
        name: parent.map(|_| "new.txt".to_string()),
        blob_path: Some(format!("/staging/{kind}")),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    }
}

#[test]
fn an_op_queued_under_a_stand_in_after_its_create_landed_goes_to_the_landed_node() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("parent", None, "My Files")).unwrap();
    let parent = uid("parent").to_string();
    let lid = db.add_local_row(&parent, "new.txt", false, 1).unwrap();
    let local = local_uid(lid);
    let real = uid("real").to_string();
    let (id, _) = db
        .enqueue_op(&op_on(OP_CREATE, &local, Some(&parent)))
        .unwrap();
    db.claim_next_due_op(1).unwrap().unwrap();
    db.finish_create(
        id,
        Some("/staging/create"),
        &landing(&local, &real, &parent, "new.txt"),
        |_| None,
    )
    .unwrap();

    // A handle opened before the create landed still names the stand-in.
    db.enqueue_op(&op_on(OP_REVISION, &local, None)).unwrap();
    assert!(db.has_pending_op(&real, OP_REVISION).unwrap());
    assert!(db.has_any_op(&real).unwrap());
    // A second write, made through the real uid, replaces it.
    let (_, superseded) = db.enqueue_op(&op_on(OP_REVISION, &real, None)).unwrap();
    assert_eq!(superseded.as_deref(), Some("/staging/revision"));
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!(
        ops[0].uid, real,
        "the queue names the node by the uid it has now"
    );
    let claimed = db.claim_next_due_op(1).unwrap().unwrap();
    assert_eq!(claimed.uid, real, "the drain sends the real uid");
}

#[test]
fn a_stand_in_keeps_its_access_once_its_create_has_landed() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("parent", None, "My Files")).unwrap();
    let parent = uid("parent").to_string();
    let lid = db.add_local_row(&parent, "new.txt", false, 1).unwrap();
    let local = local_uid(lid);
    let stand_in = NodeUid::new(VolumeId::from("local"), LinkId::from(lid.to_string()));
    let mut node = file("new", "parent", "new.txt", 1);
    node.uid = stand_in.clone();
    db.upsert_node(&node).unwrap();
    let real = uid("real").to_string();
    let (id, _) = db
        .enqueue_op(&op_on(OP_CREATE, &local, Some(&parent)))
        .unwrap();
    assert_eq!(
        db.effective_node_access(&stand_in).unwrap(),
        Some(crate::Access::Owner)
    );
    db.claim_next_due_op(1).unwrap().unwrap();
    db.finish_create(
        id,
        Some("/staging/create"),
        &landing(&local, &real, &parent, "new.txt"),
        |_| None,
    )
    .unwrap();

    // The tree still names the file by its stand-in for a moment.
    assert_eq!(
        db.effective_node_access(&stand_in).unwrap(),
        Some(crate::Access::Owner)
    );
    assert_eq!(
        db.effective_node_access(&uid("real")).unwrap(),
        Some(crate::Access::Owner)
    );
}

#[test]
fn a_stand_in_folder_stays_listed_once_its_create_has_landed() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("parent", None, "My Files")).unwrap();
    let parent = uid("parent").to_string();
    let lid = db.add_local_row(&parent, "dir", true, 1).unwrap();
    let local = local_uid(lid);
    let stand_in = NodeUid::new(VolumeId::from("local"), LinkId::from(lid.to_string()));
    let mut node = folder("new", Some("parent"), "dir");
    node.uid = stand_in.clone();
    db.upsert_node(&node).unwrap();
    db.set_listed(&stand_in, true).unwrap();
    let real = uid("real").to_string();
    let (id, _) = db
        .enqueue_op(&op_on(OP_MKDIR, &local, Some(&parent)))
        .unwrap();
    db.claim_next_due_op(1).unwrap().unwrap();
    db.finish_create(id, None, &landing(&local, &real, &parent, "dir"), |_| None)
        .unwrap();

    // The tree still names the folder by its stand-in for a moment; a listing
    // asked by it must not go to Drive, which has never heard of it.
    assert!(
        db.children_if_listed(&stand_in)
            .unwrap()
            .is_some_and(|kids| kids.is_empty())
    );
    db.set_listed(&stand_in, false).unwrap();
    assert!(db.children_if_listed(&uid("real")).unwrap().is_none());
}

#[test]
fn a_node_queued_under_both_its_uids_is_sent_one_op_at_a_time() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("parent", None, "My Files")).unwrap();
    let parent = uid("parent").to_string();
    let lid = db.add_local_row(&parent, "new.txt", false, 1).unwrap();
    let local = local_uid(lid);
    let real = uid("real").to_string();
    db.land_placeholder_row(&local, &real).unwrap();
    db.enqueue_op(&op_on(OP_RENAME, &real, Some(&parent)))
        .unwrap();
    db.enqueue_op(&op_on(OP_REVISION, &local, None)).unwrap();

    let first = db.claim_next_due_op(1).unwrap().unwrap();
    assert_eq!(first.kind, OP_RENAME);
    assert!(
        db.claim_next_due_op(1).unwrap().is_none(),
        "the write waits for the rename of the same node"
    );
    db.delete_op(first.id).unwrap();
    let second = db.claim_next_due_op(1).unwrap().unwrap();
    assert_eq!(
        (second.kind.as_str(), second.uid.as_str()),
        (OP_REVISION, real.as_str())
    );
}

#[test]
fn a_rename_made_while_its_create_uploads_is_queued_for_the_landed_node() {
    let db = Db::open_in_memory().unwrap();
    let local = "local~abc";
    let real = uid("real").to_string();
    let parent = uid("parent").to_string();
    let (id, _) = db
        .enqueue_op(&PendingOp {
            id: 0,
            kind: OP_CREATE.to_string(),
            uid: local.to_string(),
            parent_uid: Some(uid("parent").to_string()),
            name: Some("new.txt".to_string()),
            blob_path: Some("/staging/sent".to_string()),
            meta_json: Some("{}".to_string()),
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap();
    // The drain took the create; the user moves the file into a folder that
    // is itself still queued.
    db.rewrite_op_target(local, "local~dir", "moved.txt")
        .unwrap();

    let mut landed = landing(local, &real, &parent, "new.txt");
    landed.landed.1 = "new (conflict).txt";
    db.finish_create(id, Some("/staging/sent"), &landed, |_| None)
        .unwrap();

    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1, "the move outlives the create");
    assert_eq!(ops[0].kind, OP_RENAME);
    assert_eq!(ops[0].uid, real);
    assert_eq!(ops[0].parent_uid.as_deref(), Some("local~dir"));
    assert_eq!(ops[0].name.as_deref(), Some("moved.txt"));
    let meta: RenameMeta = serde_json::from_str(ops[0].meta_json.as_deref().unwrap()).unwrap();
    assert_eq!(meta.original_parent_uid, uid("parent").to_string());
    assert_eq!(meta.original_name.as_deref(), Some("new (conflict).txt"));

    // The folder lands next and the move follows it.
    db.land_placeholder_row("local~dir", &uid("dir").to_string())
        .unwrap();
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops[0].parent_uid, Some(uid("dir").to_string()));
}

#[test]
fn draining_a_folder_repoints_its_queued_children() {
    let db = Db::open_in_memory().unwrap();
    let local_dir = "local~dir";
    let real_dir = uid("realdir").to_string();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_CREATE.to_string(),
        uid: "local~child".to_string(),
        parent_uid: Some(local_dir.to_string()),
        name: Some("inside.txt".to_string()),
        blob_path: Some("/staging/child".to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 2,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();

    db.land_placeholder_row(local_dir, &real_dir).unwrap();

    // The child was queued against a folder that did not exist yet. Once the
    // folder is real, the child must target the server's uid — otherwise the
    // upload would address `local~dir` and 404.
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops[0].parent_uid.as_deref(), Some(real_dir.as_str()));
}

/// B120: a child queued inside a folder that has just landed is checked
/// against the folder's real uid before the server's copy of it arrives.
#[test]
fn a_landed_folder_keeps_a_row_until_the_server_copy_replaces_it() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    let local = NodeUid::new(VolumeId::from("local"), LinkId::from("dir"));
    let mut placeholder = folder("dir", Some("root"), "New folder");
    placeholder.uid = local.clone();
    db.upsert_node(&placeholder).unwrap();
    let mut child = file("child", "root", "inside.txt", 1);
    child.parent_uid = Some(local.clone());
    db.upsert_node(&child).unwrap();
    let (id, _) = db
        .enqueue_op(&PendingOp {
            id: 0,
            kind: OP_MKDIR.to_string(),
            uid: local.to_string(),
            parent_uid: Some(uid("root").to_string()),
            name: Some("New folder".to_string()),
            blob_path: None,
            meta_json: None,
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap();

    db.finish_create(
        id,
        None,
        &landing(
            &local.to_string(),
            &uid("real").to_string(),
            &uid("root").to_string(),
            "New folder",
        ),
        |_| None,
    )
    .unwrap();

    assert!(db.node_by_uid(&local.to_string()).unwrap().is_none());
    let landed = db
        .node_by_uid(&uid("real").to_string())
        .unwrap()
        .expect("the landed folder has a row before the server's copy is read");
    assert_eq!(landed.uid, uid("real"));
    assert_eq!(landed.name, "New folder");
    assert_eq!(
        db.effective_node_access(&uid("child")).unwrap(),
        Some(crate::Access::Owner),
        "the child's authority resolves without a network re-read"
    );
    let names: Vec<_> = db
        .known_children(&uid("real"))
        .unwrap()
        .into_iter()
        .map(|n| n.name)
        .collect();
    assert_eq!(names, ["inside.txt"]);
    let found = db.search("inside", 10).unwrap();
    assert_eq!(found.len(), 1);
    assert_eq!(found[0].path, "New folder/inside.txt");
}

/// A queued create names its folder by local id, so it is sent into the folder
/// as soon as the folder's row has its real uid, whatever the op's own copy
/// of the folder's uid still says.
#[test]
fn a_create_waits_for_its_folder_by_local_id() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    let local = NodeUid::new(VolumeId::from("local"), LinkId::from("dir"));
    let mut placeholder = folder("dir", Some("root"), "New folder");
    placeholder.uid = local.clone();
    db.upsert_node(&placeholder).unwrap();
    let dir = db.lid_of(&local.to_string()).unwrap().unwrap();
    let (id, _) = db
        .enqueue_op(&PendingOp {
            id: 0,
            kind: OP_CREATE.to_string(),
            uid: "local~child".to_string(),
            parent_uid: Some(local.to_string()),
            name: Some("inside.txt".to_string()),
            blob_path: None,
            meta_json: None,
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap();
    let parent_lid: Option<i64> = db
        .conn
        .lock()
        .query_row(
            "SELECT parent_lid FROM pending_op WHERE id = ?1",
            [id],
            |r| r.get(0),
        )
        .unwrap();
    assert_eq!(parent_lid, Some(dir));
    assert!(
        db.claim_next_due_op(1).unwrap().is_none(),
        "nothing to send into a folder that has not landed"
    );

    db.conn
        .lock()
        .execute(
            "UPDATE nodes SET uid = ?2 WHERE lid = ?1",
            rusqlite::params![dir, uid("dir").to_string()],
        )
        .unwrap();

    let op = db.claim_next_due_op(1).unwrap().expect("the create is due");
    assert_eq!(op.id, id);
    assert_eq!(op.parent_uid, Some(uid("dir").to_string()));
}

fn parent_lid(db: &Db, uid: &NodeUid) -> Option<i64> {
    db.conn
        .lock()
        .query_row(
            "SELECT parent_lid FROM nodes WHERE uid = ?1",
            [uid.to_string()],
            |r| r.get(0),
        )
        .unwrap()
}

/// A node stored before its folder, as an event can bring it, is linked to
/// the folder by local id once the folder's row arrives.
#[test]
fn a_node_stored_before_its_folder_is_linked_when_the_folder_arrives() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&file("child", "dir", "inside.txt", 1))
        .unwrap();
    assert_eq!(parent_lid(&db, &uid("child")), None);

    db.upsert_node(&folder("dir", Some("root"), "Folder"))
        .unwrap();

    assert_eq!(
        parent_lid(&db, &uid("child")),
        db.lid_of(&uid("dir").to_string()).unwrap()
    );
    assert_eq!(
        parent_lid(&db, &uid("dir")),
        db.lid_of(&uid("root").to_string()).unwrap()
    );
}

/// A restart puts a node below the folder its row links to by local id, under
/// the uid that row has now, whatever the node's own copy of it says.
#[test]
fn a_restart_finds_a_node_under_its_landed_folder() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    let local = NodeUid::new(VolumeId::from("local"), LinkId::from("dir"));
    let mut placeholder = folder("dir", Some("root"), "New folder");
    placeholder.uid = local.clone();
    db.upsert_node(&placeholder).unwrap();
    let mut child = file("child", "root", "inside.txt", 1);
    child.parent_uid = Some(local.clone());
    db.upsert_node(&child).unwrap();
    let dir = db.lid_of(&local.to_string()).unwrap().unwrap();
    db.conn
        .lock()
        .execute(
            "UPDATE nodes SET uid = ?2 WHERE lid = ?1",
            rusqlite::params![dir, uid("dir").to_string()],
        )
        .unwrap();

    let stored = db.load_all().unwrap();
    let child = stored.iter().find(|s| s.node.uid == uid("child")).unwrap();
    assert_eq!(child.node.parent_uid, Some(uid("dir")));
}

/// A rename queued against the row Drive listed for a folder still landing
/// follows the folder when that row is merged into the landing one (B140).
#[test]
fn an_op_on_a_listed_twin_follows_the_folder_that_lands() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    let local = NodeUid::new(VolumeId::from("local"), LinkId::from("dir"));
    let mut placeholder = folder("dir", Some("root"), "New folder");
    placeholder.uid = local.clone();
    db.upsert_node(&placeholder).unwrap();
    db.upsert_node(&folder("real", Some("root"), "New folder"))
        .unwrap();
    let kept = db.lid_of(&local.to_string()).unwrap().unwrap();
    let (rename, _) = db
        .enqueue_op(&PendingOp {
            id: 0,
            kind: OP_RENAME.to_string(),
            uid: uid("real").to_string(),
            parent_uid: Some(uid("root").to_string()),
            name: Some("Renamed".to_string()),
            blob_path: None,
            meta_json: None,
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap();

    db.land_placeholder_row(&local.to_string(), &uid("real").to_string())
        .unwrap();

    let lid: Option<i64> = db
        .conn
        .lock()
        .query_row("SELECT lid FROM pending_op WHERE id = ?1", [rename], |r| {
            r.get(0)
        })
        .unwrap();
    assert_eq!(lid, Some(kept));
    assert_eq!(db.lid_of(&uid("real").to_string()).unwrap(), Some(kept));
}

/// B148: a folder pinned before it landed is still pinned once it has.
#[test]
fn a_folder_pinned_before_it_landed_stays_pinned() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    let local = NodeUid::new(VolumeId::from("local"), LinkId::from("dir"));
    let mut placeholder = folder("dir", Some("root"), "Keep");
    placeholder.uid = local.clone();
    db.upsert_node(&placeholder).unwrap();
    db.pin_add(&local.to_string(), "Keep", true).unwrap();
    let (id, _) = db
        .enqueue_op(&PendingOp {
            id: 0,
            kind: OP_MKDIR.to_string(),
            uid: local.to_string(),
            parent_uid: Some(uid("root").to_string()),
            name: Some("Keep".to_string()),
            blob_path: None,
            meta_json: None,
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap();

    db.finish_create(
        id,
        None,
        &landing(
            &local.to_string(),
            &uid("real").to_string(),
            &uid("root").to_string(),
            "Keep",
        ),
        |_| None,
    )
    .unwrap();

    assert!(db.is_pinned(&uid("real").to_string()).unwrap());
    assert!(!db.is_pinned(&local.to_string()).unwrap());
    let pins = db.pin_list().unwrap();
    assert_eq!(pins.len(), 1);
    assert_eq!(pins[0].uid, uid("real").to_string());
    assert!(pins[0].recursive);
}

/// A file deleted while its create was on the wire still lands: nothing stops
/// an upload in flight. The node it made is unwanted, so a trash of it is
/// queued in the same transaction, already claimed by the drain that landed it
/// (`docs/BUGS.md` B129).
#[test]
fn a_create_withdrawn_while_it_uploads_queues_a_trash_of_the_landed_node() {
    let db = Db::open_in_memory().unwrap();
    let local = "local~gone";
    let real = uid("real").to_string();
    let parent = uid("parent").to_string();
    let (id, _) = db
        .enqueue_op(&PendingOp {
            id: 0,
            kind: OP_CREATE.to_string(),
            uid: local.to_string(),
            parent_uid: Some(parent.clone()),
            name: Some("d".to_string()),
            blob_path: Some("/staging/sent".to_string()),
            meta_json: Some("{}".to_string()),
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap();
    db.claim_next_due_op(10)
        .unwrap()
        .expect("the drain takes the create");
    db.delete_ops_for_uid(local).unwrap();

    let retired = db
        .finish_create(
            id,
            Some("/staging/sent"),
            &landing(local, &real, &parent, "d"),
            |_| None,
        )
        .unwrap();

    let CreateRetired::Withdrawn { trash } = retired else {
        panic!("a withdrawn create is not landed: {retired:?}");
    };
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!(ops[0].id, trash);
    assert_eq!(ops[0].kind, OP_TRASH);
    assert_eq!(ops[0].uid, real);
    assert_eq!(ops[0].name.as_deref(), Some("d"));
    assert!(
        db.claim_next_due_op(i64::MAX / 2).unwrap().is_none(),
        "the trash is the landing drain's to send"
    );
}

/// A file deleted after its create was sent and failed may still have been
/// made: the answer can be lost after Drive made it. Its trash keeps the
/// create's folder and blob to find that node by, and holds the name in the
/// folder until it is done (`docs/BUGS.md` B151). A create never sent goes,
/// blob and all.
#[test]
fn a_create_withdrawn_after_it_failed_queues_a_trash_that_keeps_its_blob() {
    let db = Db::open_in_memory().unwrap();
    let parent = uid("parent").to_string();
    let create = |local: &str, blob: &str| {
        db.enqueue_op(&PendingOp {
            id: 0,
            kind: OP_CREATE.to_string(),
            uid: local.to_string(),
            parent_uid: Some(parent.clone()),
            name: Some("f.txt".to_string()),
            blob_path: Some(blob.to_string()),
            meta_json: Some("{}".to_string()),
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap()
        .0
    };
    let sent = create("local~sent", "/staging/sent");
    create("local~unsent", "/staging/unsent");
    db.record_op_failure(sent, "no answer", 0).unwrap();

    assert!(db.delete_ops_for_uid("local~sent").unwrap().is_empty());
    assert_eq!(
        db.delete_ops_for_uid("local~unsent").unwrap(),
        vec!["/staging/unsent".to_string()]
    );

    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!(ops[0].kind, OP_TRASH);
    assert_eq!(ops[0].uid, "local~sent");
    assert_eq!(ops[0].parent_uid.as_deref(), Some(parent.as_str()));
    assert_eq!(ops[0].blob_path.as_deref(), Some("/staging/sent"));
    assert!(db.has_withdrawn_create(&parent, "f.txt").unwrap());
    assert!(!db.has_withdrawn_create(&parent, "g.txt").unwrap());

    let local = NodeUid::new(VolumeId::from("local"), LinkId::from("sent"));
    assert_eq!(
        db.complete_trash_op(sent, &local).unwrap().as_deref(),
        Some("/staging/sent")
    );
    assert!(db.pending_ops().unwrap().is_empty());
}

/// What a queued create sent, and where, stays on its row: through a newer
/// blob, through the turn into a trash a delete makes of it, and across a
/// reopen. The trash finds the file the create made by those bytes, after a
/// restart too, and under a name the file had before a rename
/// (`docs/BUGS.md` B183, B184).
#[test]
fn what_a_create_sent_outlives_a_newer_blob_its_trash_and_a_restart() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-create-sent-{}-{}.db",
        std::process::id(),
        now_test_id()
    ));
    let parent = uid("parent").to_string();
    let id = {
        let db = Db::open(&path).unwrap();
        let (id, _) = db
            .enqueue_op(&PendingOp {
                id: 0,
                kind: OP_CREATE.to_string(),
                uid: "local~sent".to_string(),
                parent_uid: Some(parent.clone()),
                name: Some("d".to_string()),
                blob_path: Some("/staging/first".to_string()),
                meta_json: Some("{}".to_string()),
                created_at: 1,
                attempts: 0,
                last_error: None,
                next_attempt_at: 0,
            })
            .unwrap();
        assert!(db.create_sent(id).unwrap().is_empty());
        assert!(db.create_targets(id).unwrap().is_empty());
        db.note_create_target(id, &parent, "c", 10).unwrap();
        db.note_create_target(id, &parent, "c", 20).unwrap();
        db.note_create_sent(id, "aaaa").unwrap();
        db.note_create_sent(id, "aaaa").unwrap();
        db.record_op_failure(id, "no answer", 0).unwrap();
        db.attach_blob_to_create("local~sent", "/staging/second", "{}")
            .unwrap()
            .expect("the create is still queued");
        db.note_create_target(id, &parent, "d", 30).unwrap();
        db.note_create_sent(id, "bbbb").unwrap();
        db.record_op_failure(id, "no answer", 0).unwrap();
        db.delete_ops_for_uid("local~sent").unwrap();
        id
    };

    let db = Db::open(&path).unwrap();
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!((ops[0].id, ops[0].kind.as_str()), (id, OP_TRASH));
    assert_eq!(db.create_sent(id).unwrap(), vec!["aaaa", "bbbb"]);
    assert_eq!(
        db.create_targets(id).unwrap(),
        vec![
            (parent.clone(), "c".to_string()),
            (parent.clone(), "d".to_string())
        ]
    );
    drop(db);
    let _ = std::fs::remove_file(path);
}

/// A queued create knows when it first went out, which is where the window
/// for adopting a node its lost answer left starts. Records written before
/// the time was kept still list their targets, and one that does not parse is
/// not replaced by the next target.
#[test]
fn a_create_remembers_when_it_was_first_sent() {
    let db = Db::open_in_memory().unwrap();
    let parent = uid("parent").to_string();
    let (id, _) = db
        .enqueue_op(&PendingOp {
            id: 0,
            kind: OP_CREATE.to_string(),
            uid: "local~first".to_string(),
            parent_uid: Some(parent.clone()),
            name: Some("a.txt".to_string()),
            blob_path: None,
            meta_json: None,
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap();
    assert_eq!(db.create_first_sent(id).unwrap(), None, "never sent");
    db.note_create_target(id, &parent, "a.txt", 500).unwrap();
    db.note_create_target(id, &parent, "a.txt", 900).unwrap();
    db.note_create_target(id, &parent, "b.txt", 700).unwrap();
    assert_eq!(db.create_first_sent(id).unwrap(), Some(500));

    let set = |json: &str| {
        db.conn
            .lock()
            .execute(
                "UPDATE pending_op SET sent_to = ?2 WHERE id = ?1",
                rusqlite::params![id, json],
            )
            .unwrap();
    };
    set(&format!(r#"[["{parent}","old.txt"]]"#));
    assert_eq!(
        db.create_targets(id).unwrap(),
        vec![(parent.clone(), "old.txt".to_string())]
    );
    assert_eq!(db.create_first_sent(id).unwrap(), None);
    db.note_create_target(id, &parent, "a.txt", 900).unwrap();
    assert_eq!(
        db.create_targets(id).unwrap().len(),
        2,
        "the old target stays"
    );
    assert_eq!(db.create_first_sent(id).unwrap(), Some(900));

    set("not json");
    db.note_create_target(id, &parent, "c.txt", 1000).unwrap();
    let raw: String = db
        .conn
        .lock()
        .query_row("SELECT sent_to FROM pending_op WHERE id = ?1", [id], |r| {
            r.get(0)
        })
        .unwrap();
    assert_eq!(
        raw, "not json",
        "an unreadable record is kept, not replaced"
    );
}

/// A write after a create failed clears its attempts, so the next try goes
/// out at once. The create was still sent: deleting the file then left no
/// trash, and the file a lost answer made stayed on Drive under the name it
/// was sent with (`docs/BUGS.md` B191).
#[test]
fn a_create_rewritten_after_it_failed_still_leaves_a_trash_when_deleted() {
    let db = Db::open_in_memory().unwrap();
    let parent = uid("parent").to_string();
    let (id, _) = db
        .enqueue_op(&PendingOp {
            id: 0,
            kind: OP_CREATE.to_string(),
            uid: "local~sent".to_string(),
            parent_uid: Some(parent.clone()),
            name: Some("a.txt".to_string()),
            blob_path: Some("/staging/first".to_string()),
            meta_json: Some("{}".to_string()),
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap();
    db.note_create_target(id, &parent, "a.txt", 10).unwrap();
    db.note_create_sent(id, "aaaa").unwrap();
    db.record_op_failure(id, "no answer", 0).unwrap();
    db.attach_blob_to_create("local~sent", "/staging/second", "{}")
        .unwrap()
        .expect("the create is still queued");

    assert!(db.delete_ops_for_uid("local~sent").unwrap().is_empty());

    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!((ops[0].id, ops[0].kind.as_str()), (id, OP_TRASH));
    assert_eq!(ops[0].blob_path.as_deref(), Some("/staging/second"));
    assert_eq!(
        db.create_targets(id).unwrap(),
        vec![(parent.clone(), "a.txt".to_string())]
    );
}

/// A create deleted after it was sent becomes a trash in its place. The
/// create's backoff, and the failure of an attempt still on the wire, are the
/// create's: the trash is due at once (`docs/BUGS.md` B171).
#[test]
fn a_create_deleted_after_it_was_sent_leaves_a_trash_that_is_due_at_once() {
    let db = Db::open_in_memory().unwrap();
    let parent = uid("parent").to_string();
    let create = |local: &str| {
        db.enqueue_op(&PendingOp {
            id: 0,
            kind: OP_CREATE.to_string(),
            uid: local.to_string(),
            parent_uid: Some(parent.clone()),
            name: Some(format!("{local}.txt")),
            blob_path: Some(format!("/staging/{local}")),
            meta_json: Some("{}".to_string()),
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap()
        .0
    };
    let failed = create("local~failed");
    db.record_attempt_failure(failed, OP_CREATE, "no answer", 50_000)
        .unwrap();
    let sending = create("local~sending");
    assert_eq!(
        db.claim_next_due_op(10).unwrap().map(|op| op.id),
        Some(sending)
    );

    db.delete_ops_for_uid("local~failed").unwrap();
    db.delete_ops_for_uid("local~sending").unwrap();
    db.record_attempt_failure(sending, OP_CREATE, "No such file or directory", 50_000)
        .unwrap();

    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 2);
    for op in &ops {
        assert_eq!(op.kind, OP_TRASH);
        assert_eq!((op.attempts, op.last_error.as_deref()), (0, None), "{op:?}");
        assert_eq!(op.next_attempt_at, 0, "{op:?}");
    }
    db.record_attempt_failure(failed, OP_TRASH, "offline", 50_000)
        .unwrap();
    let trash = db
        .pending_ops()
        .unwrap()
        .into_iter()
        .find(|op| op.id == failed);
    assert_eq!(trash.map(|op| op.attempts), Some(1));
}

#[test]
fn a_landed_placeholder_never_overwrites_the_server_copy() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    let local = NodeUid::new(VolumeId::from("local"), LinkId::from("dir"));
    let mut placeholder = folder("dir", Some("root"), "New folder");
    placeholder.uid = local.clone();
    db.upsert_node(&placeholder).unwrap();
    // The event stream reported the folder before the drain got round to it.
    db.upsert_node(&folder("real", Some("root"), "New folder (1)"))
        .unwrap();

    db.land_placeholder_row(&local.to_string(), &uid("real").to_string())
        .unwrap();

    assert!(db.node_by_uid(&local.to_string()).unwrap().is_none());
    assert_eq!(
        db.node_by_uid(&uid("real").to_string())
            .unwrap()
            .map(|n| n.name),
        Some("New folder (1)".to_string())
    );
}

#[test]
fn a_node_keeps_its_lid_across_updates_and_a_new_one_never_reuses_it() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&file("a", "root", "a.txt", 1)).unwrap();
    db.upsert_node(&file("b", "root", "b.txt", 1)).unwrap();
    let a = db.lid_of(&uid("a").to_string()).unwrap().unwrap();
    let b = db.lid_of(&uid("b").to_string()).unwrap().unwrap();

    db.upsert_node(&file("a", "root", "renamed.txt", 2))
        .unwrap();
    assert_eq!(db.lid_of(&uid("a").to_string()).unwrap(), Some(a));

    db.delete_node(&uid("b")).unwrap();
    db.upsert_node(&file("c", "root", "c.txt", 1)).unwrap();
    let c = db.lid_of(&uid("c").to_string()).unwrap().unwrap();
    assert!(c > b, "lid {c} reuses one a deleted row had");
}

#[test]
fn a_lid_handed_out_before_the_node_is_stored_reads_as_no_node() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.set_share_access(&uid("root"), crate::Access::Owner)
        .unwrap();
    let stub = file("stub", "root", "stub.txt", 1);
    let [lid] = db.lids_for(&[&stub]).unwrap()[..] else {
        panic!("one lid per node");
    };

    assert_eq!(db.lid_of(&uid("stub").to_string()).unwrap(), Some(lid));
    assert_eq!(db.lids_for(&[&stub]).unwrap(), vec![lid]);
    assert!(db.node_by_uid(&uid("stub").to_string()).unwrap().is_none());
    assert!(db.effective_node_access(&uid("stub")).unwrap().is_none());
    assert!(db.node_path(&uid("stub").to_string()).unwrap().is_none());
    assert!(!db.has_children(&uid("root")).unwrap());
    assert!(db.search("stub", 10).unwrap().is_empty());
    assert!(db.load_all().unwrap().iter().all(|n| n.lid != lid));

    db.upsert_node(&stub).unwrap();
    assert_eq!(db.lid_of(&uid("stub").to_string()).unwrap(), Some(lid));
    assert!(db.has_children(&uid("root")).unwrap());
}

#[test]
fn a_landed_placeholder_keeps_its_lid() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    for known in [false, true] {
        let local = NodeUid::new(VolumeId::from("local"), LinkId::from(format!("{known}")));
        let real = uid(&format!("real-{known}"));
        let mut placeholder = folder("dir", Some("root"), "New folder");
        placeholder.uid = local.clone();
        db.upsert_node(&placeholder).unwrap();
        let lid = db.lid_of(&local.to_string()).unwrap().unwrap();
        if known {
            // The event stream reported the folder before the drain got round
            // to it.
            let mut listed = folder("x", Some("root"), "New folder (1)");
            listed.uid = real.clone();
            db.upsert_node(&listed).unwrap();
        }

        db.land_placeholder_row(&local.to_string(), &real.to_string())
            .unwrap();

        assert_eq!(db.lid_of(&local.to_string()).unwrap(), None);
        assert_eq!(db.lid_of(&real.to_string()).unwrap(), Some(lid));
        assert_eq!(db.uid_of_lid(lid).unwrap(), Some(real.to_string()));
        let name = if known {
            "New folder (1)"
        } else {
            "New folder"
        };
        assert_eq!(
            db.node_by_uid(&real.to_string()).unwrap().map(|n| n.name),
            Some(name.to_string())
        );
        assert_eq!(db.search(name, 10).unwrap().len(), 1, "{name}");
    }
}

/// Drive lists none of what is queued for a folder, so a listing read from
/// it is laid over with what the queue made, moved in and moved away (B132).
#[test]
fn queued_children_are_what_drive_does_not_list_yet() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("dir", Some("root"), "dir")).unwrap();
    db.upsert_node(&folder("other", Some("root"), "other"))
        .unwrap();
    let op = |kind: &str, uid: &str, parent: &str, name: &str| PendingOp {
        id: 0,
        kind: kind.to_string(),
        uid: uid.to_string(),
        parent_uid: Some(parent.to_string()),
        name: Some(name.to_string()),
        blob_path: None,
        meta_json: None,
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    let dir = uid("dir").to_string();
    let other = uid("other").to_string();

    let local = NodeUid::new(VolumeId::from("local"), LinkId::from("new"));
    let mut made = file("x", "dir", "made.txt", 3);
    made.uid = local.clone();
    db.upsert_node(&made).unwrap();
    db.enqueue_op(&op(OP_CREATE, &local.to_string(), &dir, "made.txt"))
        .unwrap();
    db.upsert_node(&file("in", "dir", "in.txt", 3)).unwrap();
    db.enqueue_op(&op(OP_RENAME, &uid("in").to_string(), &dir, "in.txt"))
        .unwrap();
    db.upsert_node(&file("out", "other", "out.txt", 3)).unwrap();
    db.enqueue_op(&op(OP_RENAME, &uid("out").to_string(), &other, "out.txt"))
        .unwrap();
    db.upsert_node(&file("still", "dir", "still.txt", 3))
        .unwrap();

    let (here, gone) = db.queued_children(&uid("dir")).unwrap();
    let mut names: Vec<_> = here.iter().map(|n| n.name.as_str()).collect();
    names.sort();
    assert_eq!(names, ["in.txt", "made.txt"]);
    assert_eq!(
        gone,
        std::collections::HashSet::from([uid("out").to_string()])
    );
}

/// A restart builds the tree from the node each row holds. A folder that
/// landed handed its children to the real uid in the row's column only, so
/// they came back under a parent no row has (B140).
#[test]
fn a_landed_folder_hands_its_children_over_in_the_stored_node_too() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    let local = NodeUid::new(VolumeId::from("local"), LinkId::from("dir"));
    let mut placeholder = folder("x", Some("root"), "dir");
    placeholder.uid = local.clone();
    db.upsert_node(&placeholder).unwrap();
    let mut child = file("child", "x", "a.txt", 3);
    child.parent_uid = Some(local.clone());
    db.upsert_node(&child).unwrap();

    db.land_placeholder_row(&local.to_string(), &uid("dir").to_string())
        .unwrap();

    let stored = db.node_by_uid(&uid("child").to_string()).unwrap().unwrap();
    assert_eq!(stored.parent_uid, Some(uid("dir")));
    let names: Vec<_> = db
        .known_children(&uid("dir"))
        .unwrap()
        .into_iter()
        .map(|n| n.name)
        .collect();
    assert_eq!(names, ["a.txt"]);
}

/// A folder made here that lands takes its real uid in its own row only. What
/// was made inside it names it by local id, and is found under the real uid.
#[test]
fn a_landed_folder_rewrites_no_row_or_op_below_it() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    let root = uid("root").to_string();
    let dir_lid = db.add_local_row(&root, "dir", true, 1).unwrap();
    let local_dir = local_uid(dir_lid);
    let mut dir = folder("x", Some("root"), "dir");
    dir.uid = NodeUid::new(VolumeId::from("local"), LinkId::from(dir_lid.to_string()));
    db.upsert_node(&dir).unwrap();
    let child_lid = db.add_local_row(&local_dir, "a.txt", false, 1).unwrap();
    let local_child = local_uid(child_lid);
    let mut child = file("y", "x", "a.txt", 3);
    child.uid = NodeUid::new(VolumeId::from("local"), LinkId::from(child_lid.to_string()));
    child.parent_uid = Some(dir.uid.clone());
    db.upsert_node(&child).unwrap();
    db.enqueue_op(&op_on(OP_CREATE, &local_child, Some(&local_dir)))
        .unwrap();

    let real_dir = uid("dir").to_string();
    db.land_placeholder_row(&local_dir, &real_dir).unwrap();

    let (stored_parent, op_parent): (String, String) = {
        let conn = db.conn.lock();
        (
            conn.query_row(
                "SELECT parent_uid FROM nodes WHERE lid = ?1",
                [child_lid],
                |r| r.get(0),
            )
            .unwrap(),
            conn.query_row("SELECT parent_uid FROM pending_op", [], |r| r.get(0))
                .unwrap(),
        )
    };
    assert_eq!(
        (stored_parent.as_str(), op_parent.as_str()),
        (local_dir.as_str(), local_dir.as_str()),
        "the child's row and op are not rewritten"
    );

    let children = db.known_children(&uid("dir")).unwrap();
    assert_eq!(children.len(), 1);
    assert_eq!(children[0].parent_uid, Some(uid("dir")));
    assert!(db.has_children(&uid("dir")).unwrap());
    assert_eq!(
        db.node_path(&local_child).unwrap().as_deref(),
        Some("dir/a.txt")
    );
    assert_eq!(
        db.pending_ops().unwrap()[0].parent_uid.as_deref(),
        Some(real_dir.as_str()),
        "the drain sends the folder's real uid"
    );

    db.delete_ops_for_uid(&real_dir).unwrap();
    assert!(
        db.pending_ops().unwrap().is_empty(),
        "removing the folder takes the create made inside it"
    );
}

/// A node the mount still holds under its stand-in, written after it landed,
/// updates the landed row: written under the stand-in, it brought the
/// placeholder row back beside it.
#[test]
fn a_stand_in_written_after_landing_updates_the_landed_row() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    let lid = db
        .add_local_row(&uid("root").to_string(), "a.txt", false, 1)
        .unwrap();
    let local = local_uid(lid);
    let mut node = file("x", "root", "a.txt", 3);
    node.uid = NodeUid::new(VolumeId::from("local"), LinkId::from(lid.to_string()));
    db.upsert_node(&node).unwrap();
    db.land_placeholder_row(&local, &uid("a").to_string())
        .unwrap();

    node.name = "b.txt".into();
    db.upsert_node(&node).unwrap();

    let rows: Vec<(i64, String, String)> = {
        let conn = db.conn.lock();
        let mut stmt = conn
            .prepare("SELECT lid, uid, name FROM nodes WHERE uid != ?1")
            .unwrap();
        stmt.query_map([uid("root").to_string()], |r| {
            Ok((r.get(0)?, r.get(1)?, r.get(2)?))
        })
        .unwrap()
        .collect::<rusqlite::Result<_>>()
        .unwrap()
    };
    assert_eq!(rows, [(lid, uid("a").to_string(), "b.txt".to_string())]);
    let landed = db.node_by_uid(&uid("a").to_string()).unwrap().unwrap();
    assert_eq!((landed.uid, landed.name), (uid("a"), "b.txt".to_string()));
}

/// A create queued inside a folder made here is sent under the folder's real
/// uid once it lands. Landing where it was sent is no move.
#[test]
fn a_create_sent_into_a_landed_folder_lands_where_it_was_queued() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    let dir_lid = db
        .add_local_row(&uid("root").to_string(), "dir", true, 1)
        .unwrap();
    let local_dir = local_uid(dir_lid);
    let child_lid = db.add_local_row(&local_dir, "new.txt", false, 1).unwrap();
    let local_child = local_uid(child_lid);
    let (id, _) = db
        .enqueue_op(&op_on(OP_CREATE, &local_child, Some(&local_dir)))
        .unwrap();
    let real_dir = uid("dir").to_string();
    db.land_placeholder_row(&local_dir, &real_dir).unwrap();

    let claimed = db.claim_next_due_op(1).unwrap().unwrap();
    assert_eq!(claimed.parent_uid.as_deref(), Some(real_dir.as_str()));
    let real = uid("new").to_string();
    db.finish_create(
        id,
        Some("/staging/create"),
        &landing(&local_child, &real, &real_dir, "new.txt"),
        |_| None,
    )
    .unwrap();
    assert!(
        db.pending_ops().unwrap().is_empty(),
        "no rename is queued for a file that landed where it was sent"
    );
}

#[test]
fn migration_v36_gives_every_node_its_rowid_as_lid() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-v35-fixture-{}-{}.db",
        std::process::id(),
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos()
    ));
    let local = NodeUid::new(VolumeId::from("local"), LinkId::from("dir"));
    {
        let db = Db::open(&path).unwrap();
        db.upsert_node(&folder("root", None, "My Files")).unwrap();
        let mut placeholder = folder("dir", Some("root"), "Offline folder");
        placeholder.uid = local.clone();
        db.upsert_node(&placeholder).unwrap();
        db.upsert_node(&file("gone", "root", "gone.txt", 1))
            .unwrap();
        db.upsert_node(&file("kept", "root", "kept-report.txt", 1))
            .unwrap();
        db.delete_node(&uid("gone")).unwrap();
        let (id, _) = db
            .enqueue_op(&PendingOp {
                id: 0,
                kind: OP_MKDIR.to_string(),
                uid: local.to_string(),
                parent_uid: Some(uid("root").to_string()),
                name: Some("Offline folder".to_string()),
                blob_path: None,
                meta_json: None,
                created_at: 1,
                attempts: 0,
                last_error: None,
                next_attempt_at: 0,
            })
            .unwrap();
        db.record_op_failure(id, "network unreachable", 5_000)
            .unwrap();
    }
    {
        // Put the file back in the state a released V35 database was in:
        // keyed by uid, with the rowids of the rows it held.
        let conn = rusqlite::Connection::open(&path).unwrap();
        conn.execute_batch(
            "CREATE TABLE nodes_v35 (
               uid TEXT PRIMARY KEY, parent_uid TEXT, name TEXT NOT NULL,
               is_dir INTEGER NOT NULL, size INTEGER, mtime INTEGER NOT NULL,
               revision_hash TEXT, trashed INTEGER NOT NULL DEFAULT 0, node_json TEXT,
               listed INTEGER NOT NULL DEFAULT 0, path TEXT
             );
             INSERT INTO nodes_v35 (rowid, uid, parent_uid, name, is_dir, size, mtime,
                                    revision_hash, trashed, node_json, listed, path)
               SELECT lid, uid, parent_uid, name, is_dir, size, mtime, revision_hash,
                      trashed, node_json, listed, path FROM nodes;
             DROP TABLE nodes;
             ALTER TABLE nodes_v35 RENAME TO nodes;
             CREATE INDEX idx_nodes_parent ON nodes(parent_uid);
             CREATE INDEX idx_nodes_name_nocase ON nodes(name COLLATE NOCASE);
             CREATE INDEX idx_nodes_parent_live ON nodes(parent_uid) WHERE trashed = 0;
             DELETE FROM sqlite_sequence WHERE name = 'nodes';
             UPDATE sync_state SET value = '35' WHERE key = 'schema_version';",
        )
        .unwrap();
    }
    let rowids: Vec<(String, i64)> = {
        let conn = rusqlite::Connection::open(&path).unwrap();
        let mut stmt = conn
            .prepare("SELECT uid, rowid FROM nodes ORDER BY rowid")
            .unwrap();
        stmt.query_map([], |r| Ok((r.get(0)?, r.get(1)?)))
            .unwrap()
            .map(|row| row.unwrap())
            .collect()
    };
    assert_eq!(rowids.len(), 3);

    let db = Db::open(&path).unwrap();
    // The placeholder goes by its row's stand-in from V41 on.
    let stand_in = |uid: &str, rowid: i64| match uid == local.to_string() {
        true => local_uid(rowid),
        false => uid.to_string(),
    };
    for (uid, rowid) in &rowids {
        let uid = stand_in(uid, *rowid);
        assert_eq!(db.lid_of(&uid).unwrap(), Some(*rowid), "{uid}");
    }
    let found = db.search("report", 10).unwrap();
    assert_eq!(found.len(), 1, "the search index still finds the node");
    assert_eq!(found[0].node.uid, uid("kept"));
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    let (_, dir) = rowids
        .iter()
        .find(|(uid, _)| *uid == local.to_string())
        .unwrap();
    assert_eq!(ops[0].uid, local_uid(*dir));
    assert_eq!(ops[0].attempts, 1);
    assert_eq!(ops[0].last_error.as_deref(), Some("network unreachable"));

    db.upsert_node(&file("new", "root", "new.txt", 1)).unwrap();
    let newest = db.lid_of(&uid("new").to_string()).unwrap().unwrap();
    assert!(newest > rowids.last().unwrap().1);
    drop(db);
    let _ = std::fs::remove_file(&path);
}

#[test]
fn migration_v41_gives_every_placeholder_its_rows_stand_in() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-v40-fixture-{}-{}.db",
        std::process::id(),
        now_test_id()
    ));
    let _ = std::fs::remove_file(&path);
    let (dir, inner) = {
        let db = Db::open(&path).unwrap();
        db.upsert_node(&folder("root", None, "My Files")).unwrap();
        let old_dir = NodeUid::new(VolumeId::from("local"), LinkId::from("1700000000000-0"));
        let old_inner = NodeUid::new(VolumeId::from("local"), LinkId::from("1700000000000-1"));
        let mut dir = folder("x", Some("root"), "Offline folder");
        dir.uid = old_dir.clone();
        db.upsert_node(&dir).unwrap();
        let mut inner = file("x", "root", "inner.txt", 0);
        inner.uid = old_inner.clone();
        inner.parent_uid = Some(old_dir.clone());
        db.upsert_node(&inner).unwrap();
        let op = |kind: &str, uid: &NodeUid, parent: &str, meta: Option<String>| PendingOp {
            id: 0,
            kind: kind.to_string(),
            uid: uid.to_string(),
            parent_uid: Some(parent.to_string()),
            name: Some("n".to_string()),
            blob_path: None,
            meta_json: meta,
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        };
        db.enqueue_op(&op(OP_MKDIR, &old_dir, &uid("root").to_string(), None))
            .unwrap();
        let staged = json!({"uid": old_inner.to_string(), "len": 0}).to_string();
        db.enqueue_op(&op(
            OP_CREATE,
            &old_inner,
            &old_dir.to_string(),
            Some(staged),
        ))
        .unwrap();
        db.pin_add(&old_dir.to_string(), "/Offline folder", true)
            .unwrap();
        let lids = (
            db.lid_of(&old_dir.to_string()).unwrap().unwrap(),
            db.lid_of(&old_inner.to_string()).unwrap().unwrap(),
        );
        drop(db);
        rusqlite::Connection::open(&path)
            .unwrap()
            .execute(
                "UPDATE sync_state SET value = '40' WHERE key = 'schema_version'",
                [],
            )
            .unwrap();
        lids
    };

    let db = Db::open(&path).unwrap();
    let (dir_uid, inner_uid) = (local_uid(dir), local_uid(inner));
    assert_eq!(db.uid_of_lid(dir).unwrap(), Some(dir_uid.clone()));
    assert_eq!(db.uid_of_lid(inner).unwrap(), Some(inner_uid.clone()));
    let stored = db.node_by_uid(&inner_uid).unwrap().unwrap();
    assert_eq!(
        stored.uid.to_string(),
        inner_uid,
        "node_json follows the row"
    );
    assert_eq!(
        stored.parent_uid.map(|p| p.to_string()),
        Some(dir_uid.clone())
    );
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops[0].uid, dir_uid);
    assert_eq!(ops[1].uid, inner_uid);
    assert_eq!(ops[1].parent_uid, Some(dir_uid.clone()));
    let staged: serde_json::Value =
        serde_json::from_str(ops[1].meta_json.as_deref().unwrap()).unwrap();
    assert_eq!(staged["uid"], inner_uid.as_str());
    let pins: Vec<String> = db.pin_list().unwrap().into_iter().map(|p| p.uid).collect();
    assert_eq!(pins, vec![dir_uid]);
    drop(db);
    let _ = std::fs::remove_file(&path);
}

/// A database as 2.8.2 wrote it (`sqlite3 .dump`, schema 35), with queued ops
/// in every state the drain leaves them in: due, parked, failing, deferred for
/// access, and claimed by a worker when the daemon stopped. The creates below
/// a folder made offline still name their parent by its `local~` placeholder.
#[test]
fn a_2_8_database_migrates_with_every_node_and_op_intact() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-2.8.2-{}-{}.db",
        std::process::id(),
        now_test_id()
    ));
    let _ = std::fs::remove_file(&path);
    rusqlite::Connection::open(&path)
        .unwrap()
        .execute_batch(include_str!("fixtures/v2.8.2.sql"))
        .unwrap();
    let (nodes, ops) = migrates_intact(&path);
    assert_eq!((nodes, ops), (8, 6));
    let db = Db::open(&path).unwrap();
    let lid_named = |name: &str| -> i64 {
        db.conn
            .lock()
            .query_row("SELECT lid FROM nodes WHERE name = ?1", [name], |r| {
                r.get(0)
            })
            .unwrap()
    };
    let (dir, inner_lid) = (lid_named("Offline folder"), lid_named("inner.txt"));
    let queued = db.pending_ops().unwrap();
    let inner = queued
        .iter()
        .find(|op| op.uid == local_uid(inner_lid))
        .unwrap();
    assert_eq!(inner.parent_uid, Some(local_uid(dir)));
    let lids: (Option<i64>, Option<i64>) = db
        .conn
        .lock()
        .query_row(
            "SELECT lid, parent_lid FROM pending_op WHERE id = ?1",
            [inner.id],
            |r| Ok((r.get(0)?, r.get(1)?)),
        )
        .unwrap();
    assert_eq!(
        lids,
        (Some(inner_lid), Some(dir)),
        "the migration names the op's node and parent by local id"
    );
    let parent_lid: Option<i64> = db
        .conn
        .lock()
        .query_row(
            "SELECT parent_lid FROM nodes WHERE lid = ?1",
            [inner_lid],
            |r| r.get(0),
        )
        .unwrap();
    assert_eq!(parent_lid, Some(dir));
    let parked = db.parked_create_ops().unwrap();
    assert_eq!(parked.len(), 1);
    assert_eq!(parked[0].name.as_deref(), Some("movie.part"));
    drop(db);
    let _ = std::fs::remove_file(&path);
}

/// The same migration over a copy of a database a released build wrote, which
/// the fixtures above cannot stand in for: years of rows, every kind of op, and
/// whatever shapes real use left behind. The copy is taken with `VACUUM INTO`
/// over a read-only connection, so the database named is never written.
///
/// `PDFS_MIGRATE_DB=~/.local/state/proton-drive-linux/cache.db cargo test -p
/// pdfs-core a_copy_of_a_real_database -- --ignored`
#[test]
#[ignore = "needs a real database: set PDFS_MIGRATE_DB"]
fn a_copy_of_a_real_database_migrates_with_every_node_and_op_intact() {
    let source = std::env::var("PDFS_MIGRATE_DB").expect("set PDFS_MIGRATE_DB");
    let path = std::env::temp_dir().join(format!("pdfs-db-real-{}.db", std::process::id()));
    let _ = std::fs::remove_file(&path);
    rusqlite::Connection::open_with_flags(&source, rusqlite::OpenFlags::SQLITE_OPEN_READ_ONLY)
        .unwrap()
        .execute("VACUUM INTO ?1", rusqlite::params![path.to_str().unwrap()])
        .unwrap();
    let (nodes, ops) = migrates_intact(&path);
    eprintln!("{nodes} nodes, {ops} queued ops");
    let _ = std::fs::remove_file(&path);
}

/// Opens the database at `path` and checks that the migration kept every node
/// on its row id and every queued op as it was. Returns how many of each.
fn migrates_intact(path: &std::path::Path) -> (usize, usize) {
    let (version, nodes, mut ops, sealed) = {
        let conn = rusqlite::Connection::open(path).unwrap();
        let version: String = conn
            .query_row(
                "SELECT value FROM sync_state WHERE key = 'schema_version'",
                [],
                |r| r.get(0),
            )
            .unwrap();
        let nodes: Vec<(String, i64)> = conn
            .prepare("SELECT uid, rowid FROM nodes")
            .unwrap()
            .query_map([], |r| Ok((r.get(0)?, r.get(1)?)))
            .unwrap()
            .map(|row| row.unwrap())
            .collect();
        let ops = rows(&conn, QUEUED);
        let sealed = rows(&conn, "SELECT * FROM own_sealed_rev ORDER BY uid");
        (version, nodes, ops, sealed)
    };
    // A node made on this machine goes by its row's stand-in from schema 41
    // on, in its ops as everywhere else.
    let stand_ins: Vec<(String, String)> = nodes
        .iter()
        .filter(|(uid, rowid)| uid.starts_with("local~") && *uid != local_uid(*rowid))
        .map(|(uid, rowid)| (uid.clone(), local_uid(*rowid)))
        .collect();
    let nodes: Vec<(String, i64)> = nodes
        .into_iter()
        .map(
            |(uid, rowid)| match stand_ins.iter().any(|(old, _)| *old == uid) {
                true => (local_uid(rowid), rowid),
                false => (uid, rowid),
            },
        )
        .collect();
    for value in ops.iter_mut().flatten() {
        if let rusqlite::types::Value::Text(text) = value {
            for (old, new) in &stand_ins {
                if text == old {
                    *text = new.clone();
                } else {
                    *text = text.replace(&format!("\"{old}\""), &format!("\"{new}\""));
                }
            }
        }
    }
    let db = Db::open(path).unwrap();
    {
        let conn = rusqlite::Connection::open(path).unwrap();
        assert_eq!(
            rows(&conn, QUEUED),
            ops,
            "every queued op survives as it was, parked, failing or deferred"
        );
        // A claim names a drain worker of the daemon that wrote the file.
        let claimed: i64 = conn
            .query_row(
                "SELECT COUNT(*) FROM pending_op WHERE claimed_at <> 0",
                [],
                |r| r.get(0),
            )
            .unwrap();
        assert_eq!(claimed, 0, "a stopped daemon's claims are released");
        assert_eq!(
            rows(&conn, "SELECT * FROM own_sealed_rev ORDER BY uid"),
            sealed
        );
    }
    if version.parse::<i64>().unwrap() < 36 {
        for (uid, rowid) in &nodes {
            assert_eq!(db.lid_of(uid).unwrap(), Some(*rowid), "{uid}");
        }
    } else {
        for (uid, _) in &nodes {
            assert!(db.lid_of(uid).unwrap().is_some(), "{uid}");
        }
    }
    drop(db);

    let db = Db::open(path).unwrap();
    let conn = rusqlite::Connection::open(path).unwrap();
    let count: i64 = conn
        .query_row("SELECT COUNT(*) FROM nodes", [], |r| r.get(0))
        .unwrap();
    assert_eq!(count as usize, nodes.len(), "no node is lost or doubled");
    let version: String = conn
        .query_row(
            "SELECT value FROM sync_state WHERE key = 'schema_version'",
            [],
            |r| r.get(0),
        )
        .unwrap();
    assert_eq!(version, SCHEMA_VERSION.to_string());
    drop(db);
    (nodes.len(), ops.len())
}

/// Every column of the queue but the drain's claim.
const QUEUED: &str = "SELECT id, kind, uid, parent_uid, name, blob_path, meta_json, created_at,
                             attempts, last_error, next_attempt_at, access_deferred_since
                      FROM pending_op ORDER BY id";

/// Every row `query` returns, every column.
fn rows(conn: &rusqlite::Connection, query: &str) -> Vec<Vec<rusqlite::types::Value>> {
    let mut stmt = conn.prepare(query).unwrap();
    let columns = stmt.column_count();
    stmt.query_map([], |r| (0..columns).map(|i| r.get(i)).collect())
        .unwrap()
        .map(|row| row.unwrap())
        .collect()
}

#[test]
fn a_failed_op_stays_queued_with_backoff() {
    let db = Db::open_in_memory().unwrap();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: uid("a").to_string(),
        parent_uid: None,
        name: None,
        blob_path: Some("/staging/blob".to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    })
    .unwrap();
    let id = db.pending_ops().unwrap()[0].id;

    db.record_op_failure(id, "network unreachable", 5_000)
        .unwrap();

    // The staged blob is the only copy of the user's bytes: a failure must
    // never drop the row, only defer it.
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!(ops[0].attempts, 1);
    assert_eq!(ops[0].last_error.as_deref(), Some("network unreachable"));
    assert_eq!(ops[0].next_attempt_at, 5_000);

    db.record_op_failure(id, "still down", 9_000).unwrap();
    assert_eq!(db.pending_ops().unwrap()[0].attempts, 2);

    db.delete_op(id).unwrap();
    assert_eq!(db.pending_op_counts().unwrap().uploads, 0);
}

#[test]
fn an_access_blocked_op_is_deferred_without_counting_an_attempt() {
    let db = Db::open_in_memory().unwrap();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: uid("blocked").to_string(),
        parent_uid: None,
        name: None,
        blob_path: Some("/staging/blocked".to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 3,
        last_error: Some("earlier network failure".to_string()),
        next_attempt_at: 0,
    })
    .unwrap();
    let before = db.pending_ops().unwrap();
    let id = before[0].id;
    let count = db.pending_op_counts().unwrap();

    db.defer_op_without_attempt(id, 5_000).unwrap();

    let after = db.pending_ops().unwrap();
    assert_eq!(after.len(), 1);
    let after_count = db.pending_op_counts().unwrap();
    assert_eq!(after_count.uploads, count.uploads);
    assert_eq!(after_count.changes, count.changes);
    assert_eq!(after[0].attempts, before[0].attempts);
    assert_eq!(after[0].last_error, before[0].last_error);
    assert_eq!(after[0].next_attempt_at, 5_000);
}

#[test]
fn access_deferral_does_not_unpark_a_transient_create() {
    let db = Db::open_in_memory().unwrap();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_CREATE.to_string(),
        uid: uid("transient").to_string(),
        parent_uid: Some(uid("parent").to_string()),
        name: Some(".part".to_string()),
        blob_path: Some("/staging/transient".to_string()),
        meta_json: Some("{}".to_string()),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: PARK_UNTIL,
    })
    .unwrap();
    let op = db.pending_ops().unwrap().remove(0);

    db.defer_op_without_attempt(op.id, 5_000).unwrap();

    assert_eq!(db.pending_ops().unwrap()[0].next_attempt_at, PARK_UNTIL);
}

/// The drain retires the op it worked on by id. An id given out again let
/// a rename that landed delete the trash queued over it.
#[test]
fn a_dropped_op_id_is_never_given_out_again() {
    let db = Db::open_in_memory().unwrap();
    let rename = |name: &str| PendingOp {
        id: 0,
        kind: OP_RENAME.to_string(),
        uid: uid("node").to_string(),
        parent_uid: Some(uid("root").to_string()),
        name: Some(name.to_string()),
        blob_path: None,
        meta_json: None,
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    let (renamed, _) = db.enqueue_op(&rename("b.txt")).unwrap();
    let in_flight = db.claim_next_due_op(10).unwrap().unwrap();
    assert_eq!(in_flight.id, renamed);

    let (trash, _) = db
        .replace_ops_with_trash(&uid("node").to_string(), "b.txt", 2)
        .unwrap();
    assert_ne!(trash, renamed);
    db.delete_op(in_flight.id).unwrap();

    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1);
    assert_eq!(ops[0].kind, OP_TRASH);
}

#[test]
fn migrate_is_idempotent() {
    let db = Db::open_in_memory().unwrap();
    // Second migrate is a no-op (already at head) and must not error.
    db.migrate().unwrap();
}

/// A queued mode switch is a promise the daemon has to keep across a restart,
/// so it lives in the row, and reaching the mode is what retires it.
#[test]
fn pending_mode_is_queued_until_the_mode_is_reached() {
    let db = Db::open_in_memory().unwrap();
    let id = db
        .sync_folder_add("/home/me/Downloads", "v~l", "s")
        .unwrap();
    assert_eq!(db.sync_folder_get(id).unwrap().unwrap().pending_mode, None);

    db.sync_folder_set_pending_mode(id, Some("ondemand"))
        .unwrap();
    assert_eq!(
        db.sync_folder_get(id)
            .unwrap()
            .unwrap()
            .pending_mode
            .as_deref(),
        Some("ondemand")
    );
    // The listing carries it too — it is what the front-ends paint from.
    assert_eq!(
        db.sync_folder_list().unwrap()[0].pending_mode.as_deref(),
        Some("ondemand")
    );

    // Landing the switch satisfies the request: a `pending_mode` outliving it
    // would have the engine try to apply the same switch on every later pass.
    db.sync_folder_set_mode(id, "ondemand").unwrap();
    let folder = db.sync_folder_get(id).unwrap().unwrap();
    assert_eq!(folder.mode, "ondemand");
    assert_eq!(folder.pending_mode, None);

    // And the user can withdraw a request that hasn't landed yet.
    db.sync_folder_set_pending_mode(id, Some("mirror")).unwrap();
    db.sync_folder_set_pending_mode(id, None).unwrap();
    let folder = db.sync_folder_get(id).unwrap().unwrap();
    assert_eq!(folder.mode, "ondemand");
    assert_eq!(folder.pending_mode, None);
}

#[test]
fn moved_sync_folder_points_at_its_new_share() {
    let db = Db::open_in_memory().unwrap();
    let id = db
        .sync_folder_add("/tmp/pdfs-moved-share", "vol~folder", "windows-share")
        .unwrap();
    let other = db
        .sync_folder_add("/tmp/pdfs-unmoved-share", "vol~other", "windows-share")
        .unwrap();

    db.sync_folder_set_share(id, "linux-share").unwrap();

    let folder = db.sync_folder_get(id).unwrap().unwrap();
    assert_eq!(folder.remote_share_id, "linux-share");
    // A move keeps the uid, so nothing but the share changes.
    assert_eq!(folder.remote_uid, "vol~folder");
    assert_eq!(
        db.sync_folder_get(other).unwrap().unwrap().remote_share_id,
        "windows-share"
    );
}

#[test]
fn mode_commit_clears_only_the_intent_it_satisfies() {
    let db = Db::open_in_memory().unwrap();
    let id = db
        .sync_folder_add("/tmp/pdfs-mode-intent", "vol~folder", "share")
        .unwrap();

    db.sync_folder_set_pending_mode(id, Some("ondemand"))
        .unwrap();
    db.sync_folder_set_mode(id, "ondemand").unwrap();
    assert_eq!(db.sync_folder_get(id).unwrap().unwrap().pending_mode, None);

    db.sync_folder_set_pending_mode(id, Some("mirror")).unwrap();
    db.sync_folder_set_mode(id, "ondemand").unwrap();
    assert_eq!(
        db.sync_folder_get(id)
            .unwrap()
            .unwrap()
            .pending_mode
            .as_deref(),
        Some("mirror")
    );
}

#[test]
fn clearing_a_stale_pending_mode_preserves_the_newer_intent() {
    let db = Db::open_in_memory().unwrap();
    let id = db
        .sync_folder_add("/tmp/pdfs-pending", "vol~folder", "share")
        .unwrap();
    db.sync_folder_set_pending_mode(id, Some("ondemand"))
        .unwrap();
    db.sync_folder_set_pending_mode(id, Some("mirror")).unwrap();

    assert!(
        !db.sync_folder_clear_pending_mode_if(id, "ondemand")
            .unwrap()
    );
    assert_eq!(
        db.sync_folder_get(id)
            .unwrap()
            .unwrap()
            .pending_mode
            .as_deref(),
        Some("mirror")
    );
    assert!(db.sync_folder_clear_pending_mode_if(id, "mirror").unwrap());
    assert_eq!(db.sync_folder_get(id).unwrap().unwrap().pending_mode, None);
}

fn baseline_row(rel: &str) -> StoredSyncEntry {
    StoredSyncEntry {
        rel_path: rel.into(),
        remote_uid: Some(format!("vol~{rel}")),
        local_mtime: 1_700_000_000,
        local_mtime_ns: Some(1_700_000_000_000_000_001),
        local_size: 7,
        remote_rev: Some("1700000000".into()),
        remote_hash: Some("7".into()),
        remote_revision_id: None,
    }
}

#[test]
fn moving_a_baseline_subtree_takes_its_rows_and_leaves_name_prefixed_siblings() {
    let db = Db::open_in_memory().unwrap();
    let from = db.sync_folder_add("/home/me/A", "vol~a", "share").unwrap();
    let to = db.sync_folder_add("/home/me/B", "vol~b", "share").unwrap();
    for rel in [
        "docs",
        "docs/x.txt",
        "docs/sub/y.txt",
        "docsextra.txt",
        "other",
    ] {
        db.sync_entry_upsert(from, &baseline_row(rel)).unwrap();
    }
    db.sync_entry_upsert(to, &baseline_row("inbox")).unwrap();

    db.sync_entries_move(from, "docs", to, "inbox/docs")
        .unwrap();

    let left = db.sync_entries(from).unwrap();
    let mut left: Vec<_> = left.keys().cloned().collect();
    left.sort();
    assert_eq!(left, ["docsextra.txt", "other"]);

    let moved = db.sync_entries(to).unwrap();
    let mut keys: Vec<_> = moved.keys().cloned().collect();
    keys.sort();
    assert_eq!(
        keys,
        [
            "inbox",
            "inbox/docs",
            "inbox/docs/sub/y.txt",
            "inbox/docs/x.txt"
        ]
    );
    // Only the path changes: the row still describes the same node on both sides.
    assert_eq!(
        moved["inbox/docs/x.txt"],
        StoredSyncEntry {
            rel_path: "inbox/docs/x.txt".into(),
            ..baseline_row("docs/x.txt")
        }
    );
}

#[test]
fn moving_a_baseline_subtree_within_one_folder_renames_it() {
    let db = Db::open_in_memory().unwrap();
    let folder = db.sync_folder_add("/home/me/A", "vol~a", "share").unwrap();
    for rel in ["old", "old/f.txt", "new"] {
        db.sync_entry_upsert(folder, &baseline_row(rel)).unwrap();
    }

    db.sync_entries_move(folder, "old", folder, "new/old")
        .unwrap();

    let mut keys: Vec<_> = db.sync_entries(folder).unwrap().into_keys().collect();
    keys.sort();
    assert_eq!(keys, ["new", "new/old", "new/old/f.txt"]);
}

#[test]
fn removing_a_baseline_subtree_keeps_name_prefixed_siblings() {
    let db = Db::open_in_memory().unwrap();
    let folder = db.sync_folder_add("/home/me/A", "vol~a", "share").unwrap();
    for rel in ["docs", "docs/x.txt", "docsextra.txt"] {
        db.sync_entry_upsert(folder, &baseline_row(rel)).unwrap();
    }

    db.sync_entries_remove_subtree(folder, "docs").unwrap();

    let keys: Vec<_> = db.sync_entries(folder).unwrap().into_keys().collect();
    assert_eq!(keys, ["docsextra.txt"]);
}

#[test]
fn mirror_uid_lookup_covers_the_root_and_synced_descendants_only() {
    let db = Db::open_in_memory().unwrap();
    let mirror = db
        .sync_folder_add("/home/me/Mirror", "vol~mirror-root", "share")
        .unwrap();
    db.sync_entry_upsert(
        mirror,
        &StoredSyncEntry {
            rel_path: "nested/file.txt".into(),
            remote_uid: Some("vol~mirror-file".into()),
            local_mtime: 1,
            local_size: 2,
            remote_rev: Some("3".into()),
            remote_hash: Some("2".into()),
            remote_revision_id: None,
            local_mtime_ns: None,
        },
    )
    .unwrap();
    let ondemand = db
        .sync_folder_add("/home/me/OnDemand", "vol~ondemand-root", "share")
        .unwrap();
    db.sync_folder_set_mode(ondemand, "ondemand").unwrap();
    db.sync_entry_upsert(
        ondemand,
        &StoredSyncEntry {
            rel_path: "stale.txt".into(),
            remote_uid: Some("vol~ondemand-stale".into()),
            local_mtime: 1,
            local_size: 2,
            remote_rev: Some("3".into()),
            remote_hash: Some("2".into()),
            remote_revision_id: None,
            local_mtime_ns: None,
        },
    )
    .unwrap();

    assert!(db.mirror_contains_uid("vol~mirror-root").unwrap());
    assert!(db.mirror_contains_uid("vol~mirror-file").unwrap());
    assert!(!db.mirror_contains_uid("vol~ondemand-root").unwrap());
    assert!(!db.mirror_contains_uid("vol~ondemand-stale").unwrap());
    assert!(!db.mirror_contains_uid("vol~missing").unwrap());
}

#[test]
fn node_path_resolves_relative_to_a_sync_root_uid() {
    let db = Db::open_in_memory().unwrap();
    let root = node_from(serde_json::Value::Null, "root", "My Files", json!("Folder"));
    let videos = node_from(json!(uid("root")), "videos", "Videos", json!("Folder"));
    let anime = node_from(json!(uid("videos")), "anime", "anime", json!("Folder"));
    let show = node_from(json!(uid("anime")), "show", "Oshi no Ko", json!("Folder"));
    let episode = node_from(
        json!(uid("show")),
        "episode",
        "episode 01.mkv",
        json!({"File": {
            "media_type": "video/x-matroska",
            "total_size_on_storage": 42,
            "claimed_size": 42,
            "claimed_modification_time": null
        }}),
    );
    db.upsert_nodes(&[root, videos, anime, show, episode])
        .unwrap();

    assert_eq!(
        db.path_relative_to(&uid("videos").to_string(), &uid("episode").to_string())
            .unwrap()
            .as_deref(),
        Some("anime/Oshi no Ko/episode 01.mkv")
    );
    assert_eq!(
        db.path_relative_to(&uid("videos").to_string(), &uid("videos").to_string())
            .unwrap()
            .as_deref(),
        Some("")
    );
    assert_eq!(
        db.path_relative_to(&uid("anime").to_string(), &uid("episode").to_string())
            .unwrap()
            .as_deref(),
        Some("Oshi no Ko/episode 01.mkv")
    );
}

#[test]
fn node_path_rejects_unrelated_missing_and_broken_ancestor_chains() {
    let db = Db::open_in_memory().unwrap();
    let root = node_from(serde_json::Value::Null, "root", "My Files", json!("Folder"));
    let videos = node_from(json!(uid("root")), "videos", "Videos", json!("Folder"));
    let episode = node_from(
        json!(uid("videos")),
        "episode",
        "episode.mkv",
        json!({"File": {
            "media_type": "video/x-matroska",
            "total_size_on_storage": 42,
            "claimed_size": 42,
            "claimed_modification_time": null
        }}),
    );
    let unrelated = node_from(
        json!(uid("root")),
        "documents",
        "Documents",
        json!("Folder"),
    );
    let orphan = node_from(
        json!(uid("missing-parent")),
        "orphan",
        "orphan.mkv",
        json!({"File": {
            "media_type": "video/x-matroska",
            "total_size_on_storage": 42,
            "claimed_size": 42,
            "claimed_modification_time": null
        }}),
    );
    db.upsert_nodes(&[root, videos, episode, unrelated, orphan])
        .unwrap();

    for (ancestor, descendant) in [
        ("documents", "episode"),
        ("videos", "missing-node"),
        ("videos", "orphan"),
    ] {
        assert_eq!(
            db.path_relative_to(&uid(ancestor).to_string(), &uid(descendant).to_string())
                .unwrap(),
            None
        );
    }
}

#[test]
fn cache_index_touch_access_and_lru_order() {
    let db = Db::open_in_memory().unwrap();
    db.cache_touch("k1", "blob", 100, 10).unwrap();
    db.cache_touch("k2", "blob", 200, 20).unwrap();
    // LRU-first: k1 (older access) before k2.
    let rows = db.cache_entries_by_kind("blob").unwrap();
    assert_eq!(rows, vec![("k1".into(), 100), ("k2".into(), 200)]);

    // Accessing k1 moves it to the back (most recent).
    db.cache_accessed("k1", 30).unwrap();
    let rows = db.cache_entries_by_kind("blob").unwrap();
    assert_eq!(rows[0].0, "k2");
    assert_eq!(rows[1].0, "k1");

    // Re-touch updates size, not just time.
    db.cache_touch("k1", "blob", 150, 40).unwrap();
    let rows = db.cache_entries_by_kind("blob").unwrap();
    assert_eq!(rows.iter().find(|(k, _)| k == "k1").unwrap().1, 150);
}

#[test]
fn cache_index_kinds_are_separate() {
    let db = Db::open_in_memory().unwrap();
    db.cache_touch("blob1", "blob", 100, 1).unwrap();
    db.cache_touch("blk1.b0", "block", 50, 1).unwrap();
    assert_eq!(db.cache_entries_by_kind("blob").unwrap().len(), 1);
    assert_eq!(db.cache_entries_by_kind("block").unwrap().len(), 1);
}

#[test]
fn cache_index_remove_and_remove_all() {
    let db = Db::open_in_memory().unwrap();
    // A blob plus two of its blocks (key prefix shared).
    db.cache_touch("abc", "blob", 1, 1).unwrap();
    db.cache_touch("abc.b0", "block", 1, 1).unwrap();
    db.cache_touch("abc.b1", "block", 1, 1).unwrap();
    // An unrelated entry that must survive.
    db.cache_touch("xyz", "blob", 1, 1).unwrap();

    db.cache_remove("abc.b0").unwrap();
    assert_eq!(db.cache_entries_by_kind("block").unwrap().len(), 1);

    // remove_all drops the blob row and every remaining block of that uid.
    db.cache_remove_all("abc").unwrap();
    assert!(db.cache_entries_by_kind("block").unwrap().is_empty());
    let blobs = db.cache_entries_by_kind("blob").unwrap();
    assert_eq!(blobs, vec![("xyz".into(), 1)]);
}

/// A rebuild is a replacement, not a merge: whatever the index said before
/// is what a stale or externally-deleted cache file would leave behind.
#[test]
fn cache_index_rebuild_replaces_every_row() {
    let db = Db::open_in_memory().unwrap();
    db.cache_touch("gone", "blob", 1, 1).unwrap();
    db.cache_touch("also-gone", "block", 1, 1).unwrap();

    db.cache_rebuild(&[CacheEntryInput {
        key: "kept",
        kind: "blob",
        size: 7,
        last_accessed: 42,
    }])
    .unwrap();

    assert_eq!(
        db.cache_entries_by_kind("blob").unwrap(),
        vec![("kept".to_string(), 7)]
    );
    assert!(db.cache_entries_by_kind("block").unwrap().is_empty());

    // An empty rebuild is how a cache directory that vanished reports itself.
    db.cache_rebuild(&[]).unwrap();
    assert!(db.cache_entries_by_kind("blob").unwrap().is_empty());
}

#[test]
fn pin_add_list_remove_roundtrip() {
    let db = Db::open_in_memory().unwrap();
    db.pin_add("vol~a", "docs/a.txt", false).unwrap();
    db.pin_add("vol~d", "docs", true).unwrap();
    let list = db.pin_list().unwrap();
    assert_eq!(list.len(), 2);
    // No `nodes` row for either pin, so the kind is unknown rather than guessed
    // from the recursive flag.
    assert_eq!(
        list[0],
        PinRow {
            uid: "vol~a".into(),
            path: "docs/a.txt".into(),
            recursive: false,
            is_dir: None,
        }
    );
    assert_eq!(
        list[1],
        PinRow {
            uid: "vol~d".into(),
            path: "docs".into(),
            recursive: true,
            is_dir: None,
        }
    );

    // Once the node is cached, the pin reports the real kind — a folder pinned
    // non-recursively must not look like a file.
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("d", Some("root"), "docs")).unwrap();
    db.pin_add("vol~d", "docs", false).unwrap();
    let list = db.pin_list().unwrap();
    assert!(!list[1].recursive, "pin policy stays non-recursive");
    assert_eq!(list[1].is_dir, Some(true), "but the node is still a folder");

    // Re-pin refreshes path/flag, not a duplicate row.
    db.pin_add("vol~a", "moved/a.txt", false).unwrap();
    let list = db.pin_list().unwrap();
    assert_eq!(list.len(), 2);
    assert_eq!(list[0].path, "moved/a.txt");

    assert!(db.pin_remove("vol~a").unwrap());
    assert!(!db.pin_remove("vol~a").unwrap());
    assert_eq!(db.pin_list().unwrap().len(), 1);
}

#[test]
fn is_pinned_direct_without_node_row() {
    // A direct pin counts even when the node was never hydrated into `nodes`.
    let db = Db::open_in_memory().unwrap();
    db.pin_add("vol~a", "a.txt", false).unwrap();
    assert!(db.is_pinned("vol~a").unwrap());
    assert!(!db.is_pinned("vol~b").unwrap());
}

#[test]
fn recursive_folder_pin_covers_subtree() {
    let db = Db::open_in_memory().unwrap();
    // root/docs/{report.pdf, sub/deep.txt}, root/loose.txt
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("docs", Some("root"), "Documents"))
        .unwrap();
    db.upsert_node(&file("rep", "docs", "report.pdf", 1))
        .unwrap();
    db.upsert_node(&folder("sub", Some("docs"), "Sub")).unwrap();
    db.upsert_node(&file("deep", "sub", "deep.txt", 1)).unwrap();
    db.upsert_node(&file("loose", "root", "loose.txt", 1))
        .unwrap();

    // Pin the Documents folder recursively (uids are `vol~link` display form).
    let du = |l: &str| uid(l).to_string();
    db.pin_add(&du("docs"), "Documents", true).unwrap();

    // Everything under docs (any depth) is pinned; loose.txt is not.
    assert!(db.is_pinned(&du("docs")).unwrap());
    assert!(db.is_pinned(&du("rep")).unwrap());
    assert!(db.is_pinned(&du("deep")).unwrap());
    assert!(!db.is_pinned(&du("loose")).unwrap());

    // pinned_uids expands the subtree (folder + descendants), no loose.txt.
    let mut got = db.pinned_uids().unwrap();
    got.sort();
    assert_eq!(got, vec![du("deep"), du("docs"), du("rep"), du("sub")]);

    // descendants() lists the subtree of a folder (excludes the folder).
    let mut desc = db.descendants(&du("docs")).unwrap();
    desc.sort();
    assert_eq!(desc, vec![du("deep"), du("rep"), du("sub")]);
}

#[test]
fn non_recursive_folder_pin_does_not_cover_children() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("docs", Some("root"), "Documents"))
        .unwrap();
    db.upsert_node(&file("rep", "docs", "report.pdf", 1))
        .unwrap();
    // A non-recursive pin on the folder covers only the folder itself.
    let du = |l: &str| uid(l).to_string();
    db.pin_add(&du("docs"), "Documents", false).unwrap();
    assert!(db.is_pinned(&du("docs")).unwrap());
    assert!(!db.is_pinned(&du("rep")).unwrap());
}

/// A `parent_uid` cycle is corrupt data the API can hand us, and `is_pinned`'s
/// ancestor walk is `UNION ALL` — uncapped it never terminates, while holding
/// the daemon's only SQLite connection, on a path that runs per cached read.
/// The answer here matters less than the fact that there is one.
#[test]
fn is_pinned_terminates_on_a_parent_cycle() {
    let db = Db::open_in_memory().unwrap();
    let du = |l: &str| uid(l).to_string();
    // a -> b -> a, with nothing pinned above either.
    db.upsert_node(&folder("a", Some("b"), "A")).unwrap();
    db.upsert_node(&folder("b", Some("a"), "B")).unwrap();
    db.upsert_node(&file("leaf", "a", "leaf.txt", 1)).unwrap();

    assert!(!db.is_pinned(&du("leaf")).unwrap());

    // And a pin *inside* the cycle is still found rather than walked past.
    db.pin_add(&du("a"), "A", true).unwrap();
    assert!(db.is_pinned(&du("leaf")).unwrap());
}

#[test]
fn schema_objects_exist() {
    let db = Db::open_in_memory().unwrap();
    let count: i64 = db
        .with_conn(|c| {
            Ok(c.query_row(
                "SELECT count(*) FROM sqlite_master
                     WHERE name IN ('nodes', 'nodes_fts', 'cache_entries')",
                [],
                |r| r.get(0),
            )?)
        })
        .unwrap();
    assert_eq!(count, 3);
}

/// A queued op carrying a realistically-sized `meta_json`, which is what made
/// the old scan expensive: the drain read and parsed every op's sidecar to pick
/// one.
fn bulk_op(i: usize, parent: &str) -> PendingOp {
    PendingOp {
        id: 0,
        kind: OP_REVISION.to_string(),
        uid: format!("vol~link{i}"),
        parent_uid: Some(parent.to_string()),
        name: Some(format!("file-{i}.bin")),
        blob_path: Some(format!("/staging/vol~link{i}-{i}")),
        // A StagedWrite sidecar, roughly the shape and size of a real one.
        meta_json: Some(format!(
            r#"{{"uid":"vol~link{i}","len":8388608,"base_size":8388608,
                 "base_mtime":1700000000,"authored":[[0,8388608]],"complete":true,
                 "based_on":{{"mtime":1700000000,"size":8388608}}}}"#
        )),
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    }
}

/// **The B3 measurement.** The drain picks one op per iteration. Doing that by
/// reading the whole queue is quadratic in queue length; doing it in SQL with
/// `LIMIT 1` is flat. Asserts the shape of the difference, not a wall-clock
/// number — the point is that one grows with the queue and the other does not.
#[test]
fn next_due_op_does_not_scale_with_queue_length() {
    use std::time::Instant;

    let db = Db::open_in_memory().unwrap();
    let root = uid("root").to_string();
    const N: usize = 2000;
    for i in 0..N {
        db.enqueue_op(&bulk_op(i, &root)).unwrap();
    }

    // Both must agree on which op is next.
    let scanned = db
        .pending_ops()
        .unwrap()
        .into_iter()
        .find(|o| o.next_attempt_at <= 10);
    let queried = db.next_due_op(10).unwrap();
    assert_eq!(
        scanned.as_ref().map(|o| o.id),
        queried.as_ref().map(|o| o.id),
        "the new query must pick the op the old scan picked"
    );
    assert_eq!(scanned.map(|o| o.uid), queried.map(|o| o.uid));

    // Simulate a drain pass: pick the next op, retire it, repeat.
    let rounds = 200;

    let t0 = Instant::now();
    for _ in 0..rounds {
        let _ = db
            .pending_ops()
            .unwrap()
            .into_iter()
            .find(|o| o.next_attempt_at <= 10);
    }
    let scan = t0.elapsed();

    let t1 = Instant::now();
    for _ in 0..rounds {
        let _ = db.next_due_op(10).unwrap();
    }
    let query = t1.elapsed();

    println!("B3: {rounds} picks over a {N}-op queue — scan {scan:?}, query {query:?}");
    assert!(
        query * 20 < scan,
        "expected the LIMIT 1 query to be far cheaper than a full scan; \
         scan={scan:?} query={query:?}"
    );
}

/// The readiness filter moved into SQL, so it needs its own coverage there: an
/// op whose parent was itself created offline is not yet sendable and must be
/// skipped in favour of a later one that is.
#[test]
fn next_due_op_skips_ops_blocked_on_a_local_parent() {
    let db = Db::open_in_memory().unwrap();
    let root = uid("root").to_string();

    db.enqueue_op(&bulk_op(1, "local~dir")).unwrap();
    db.enqueue_op(&bulk_op(2, &root)).unwrap();

    let next = db.next_due_op(10).unwrap().expect("an op is due");
    assert_eq!(next.uid, "vol~link2", "skipped the local-parent op");

    // A NULL parent is not blocked.
    let mut orphan = bulk_op(3, &root);
    orphan.parent_uid = None;
    db.enqueue_op(&orphan).unwrap();
    db.delete_op(next.id).unwrap();
    assert_eq!(db.next_due_op(10).unwrap().unwrap().uid, "vol~link3");
}

/// B70: a transient file's create is parked so its bytes never upload while it
/// wears that name, the park survives a write attaching its blob, and the
/// finalize rename (un-park) is what finally makes the completed file due.
#[test]
fn a_parked_transient_create_stays_off_the_drain_until_finalized() {
    let db = Db::open_in_memory().unwrap();
    let node = uid("dl").to_string();
    let parent = uid("root").to_string();
    db.enqueue_op(&PendingOp {
        id: 0,
        kind: OP_CREATE.to_string(),
        uid: node.clone(),
        parent_uid: Some(parent),
        name: Some("movie.mkv.part".to_string()),
        blob_path: None,
        meta_json: None,
        created_at: 1,
        attempts: 0,
        last_error: None,
        next_attempt_at: PARK_UNTIL,
    })
    .unwrap();

    // Parked: never selected, however far the clock advances.
    assert!(
        db.next_due_op(PARK_UNTIL - 1).unwrap().is_none(),
        "a parked create is never due"
    );

    // A write attaches its blob to the create but must not wake it.
    let attached = db
        .attach_blob_to_create(&node, "/staging/blob1", "{}")
        .unwrap();
    assert!(attached.is_some(), "the blob attached to the create");
    assert!(
        db.next_due_op(PARK_UNTIL - 1).unwrap().is_none(),
        "still parked after a write attaches"
    );

    // Finalize: un-park, and the completed file is due to upload with its bytes.
    assert!(
        db.set_create_hold(&node, false).unwrap(),
        "a create row was un-parked"
    );
    let due = db
        .next_due_op(1_000)
        .unwrap()
        .expect("the un-parked create is due");
    assert_eq!(due.uid, node);
    assert_eq!(due.blob_path.as_deref(), Some("/staging/blob1"));
}

/// The park sweep's query: parked creates are the rows nothing else in the drain
/// can see, so it has to find them by the sentinel and report how long each has
/// been parked. Ordinary queued work is not its business.
#[test]
fn parked_creates_are_listed_with_the_age_the_sweep_judges_them_by() {
    let db = Db::open_in_memory().unwrap();
    let parent = uid("root").to_string();
    let parked = uid("swap").to_string();
    let due = uid("ordinary").to_string();
    for (node, name, next_attempt_at, created_at) in [
        (&parked, ".notes.txt.swp", PARK_UNTIL, 1_000),
        (&due, "notes.txt", 0, 2_000),
    ] {
        db.enqueue_op(&PendingOp {
            id: 0,
            kind: OP_CREATE.to_string(),
            uid: node.clone(),
            parent_uid: Some(parent.clone()),
            name: Some(name.to_string()),
            blob_path: Some(format!("/staging/{name}")),
            meta_json: None,
            created_at,
            attempts: 0,
            last_error: None,
            next_attempt_at,
        })
        .unwrap();
    }

    let rows = db.parked_create_ops().unwrap();
    assert_eq!(rows.len(), 1, "only the parked create is swept");
    assert_eq!(rows[0].uid, parked);
    assert_eq!(rows[0].created_at, 1_000, "the park's age is readable");
    assert_eq!(
        rows[0].blob_path.as_deref(),
        Some("/staging/.notes.txt.swp")
    );

    // What the sweep does with an expired park: un-park it, and it drains like
    // any other create rather than waiting for a rename that is not coming.
    assert!(db.set_create_hold(&parked, false).unwrap());
    assert!(
        db.parked_create_ops().unwrap().is_empty(),
        "an un-parked create is no longer the sweep's business"
    );
    assert_eq!(
        db.next_due_op(1_000 + PARK_EXPIRY_MS).unwrap().unwrap().uid,
        parked
    );
}

/// Backoff still gates: nothing is returned before an op is due.
#[test]
fn next_due_op_respects_backoff() {
    let db = Db::open_in_memory().unwrap();
    let root = uid("root").to_string();
    let id = db.enqueue_op(&bulk_op(1, &root)).unwrap().0;
    db.record_op_failure(id, "boom", 5_000).unwrap();

    assert!(
        db.next_due_op(4_999).unwrap().is_none(),
        "still backing off"
    );
    assert!(db.next_due_op(5_000).unwrap().is_some(), "due now");
}

/// **The B4 measurement.** `enforce_block_budget` runs on *every* `store_block`,
/// i.e. once per 4 MiB of every cold read. The old path read and sorted every
/// row of the cache index to answer a question that is almost always "no, we are
/// under budget" — under the shared connection lock, so it also stalled FUSE
/// metadata calls.
///
/// Asserts correctness — the aggregate must agree with summing the rows, and
/// must count the kinds apart — and *reports* the timing without asserting on
/// it. See the note at the measurement for why.
#[test]
fn cache_total_bytes_agrees_with_summing_the_rows() {
    use std::time::Instant;

    let db = Db::open_in_memory().unwrap();
    // A 20 GB block cache at 4 MiB a block is ~5000 rows.
    const N: usize = 5000;
    const BLOCK: u64 = 4 << 20;
    for i in 0..N {
        db.cache_touch(&format!("k{i}.b0"), "block", BLOCK, i as i64)
            .unwrap();
    }

    // The aggregate must agree with summing the rows.
    let summed: u64 = db
        .cache_entries_by_kind("block")
        .unwrap()
        .iter()
        .map(|(_, s)| s)
        .sum();
    assert_eq!(db.cache_total_bytes("block").unwrap(), summed);
    assert_eq!(summed, N as u64 * BLOCK);
    // Kinds are counted apart.
    assert_eq!(db.cache_total_bytes("blob").unwrap(), 0);

    let rounds = 500;

    let t0 = Instant::now();
    for _ in 0..rounds {
        let entries = db.cache_entries_by_kind("block").unwrap();
        let _: u64 = entries.iter().map(|(_, s)| *s).sum();
    }
    let scan = t0.elapsed();

    let t1 = Instant::now();
    for _ in 0..rounds {
        let _ = db.cache_total_bytes("block").unwrap();
    }
    let aggregate = t1.elapsed();

    // Reported, not asserted. The SUM is cheaper than reading every row — no
    // materialization, no allocation, no sort — but it is still O(rows), so this
    // is a constant factor, and an assertion on a constant factor measured
    // alongside the rest of the suite tests the machine's load as much as the
    // query. The claim that matters — that the *common* path does not touch the
    // database at all — is pinned by `budget_check_is_free_when_under_budget`,
    // which compares against itself and so is load-independent.
    println!(
        "B4: {rounds} budget checks over {N} entries — scan {scan:?}, aggregate {aggregate:?}"
    );
}

/// Victims still come out least-recently-accessed first, now in bounded batches
/// rather than one unbounded read of the table.
#[test]
fn cache_eviction_candidates_are_lru_ordered_and_limited() {
    let db = Db::open_in_memory().unwrap();
    for i in 0..10u64 {
        // Insert newest-first so insertion order cannot be mistaken for LRU order.
        db.cache_touch(&format!("k{i}"), "blob", 100, (10 - i) as i64)
            .unwrap();
    }
    db.cache_touch("other", "block", 100, 0).unwrap();

    let batch = db.cache_eviction_candidates("blob", 3).unwrap();
    assert_eq!(batch.len(), 3, "honours the limit");
    let keys: Vec<&str> = batch.iter().map(|(k, _)| k.as_str()).collect();
    assert_eq!(keys, ["k9", "k8", "k7"], "least-recently-accessed first");
    assert!(
        batch.iter().all(|(k, _)| k != "other"),
        "a different kind is never a candidate"
    );
}

/// **The B5 checkpoint.** A performance plan proposed concurrent SQLite
/// reads, on the premise that the single `Mutex<Connection>` serializes the FUSE
/// workers. This measures what the connection is actually asked to do now that
/// B3 and B4 have landed, so the proposal is decided on evidence.
///
/// Note what is *not* here: `lookup`/`getattr`/`readdir` do not read this
/// database in the steady state — they serve from `State::entries` in memory and
/// only write through on a cold fill. The per-read DB operation is
/// `cache_accessed`, one `UPDATE` per cache hit, which is what this drives.
#[test]
fn db_contention_under_fuse_worker_load() {
    use std::sync::Arc;
    use std::time::Instant;

    let db = Arc::new(Db::open_in_memory().unwrap());
    for i in 0..5000u64 {
        db.cache_touch(&format!("k{i}.b0"), "block", 4 << 20, i as i64)
            .unwrap();
    }

    // Eight workers, matching FUSE_WORKERS, each doing what a served block read
    // does to the database: one LRU touch.
    const WORKERS: usize = 8;
    const PER_WORKER: usize = 2000;

    let t = Instant::now();
    let mut handles = Vec::new();
    for w in 0..WORKERS {
        let db = db.clone();
        handles.push(std::thread::spawn(move || {
            for i in 0..PER_WORKER {
                db.cache_accessed(&format!("k{}.b0", (w * PER_WORKER + i) % 5000), i as i64)
                    .unwrap();
            }
        }));
    }
    for h in handles {
        h.join().unwrap();
    }
    let concurrent = t.elapsed();

    // The same work on one thread, for the serialization baseline.
    let t = Instant::now();
    for i in 0..(WORKERS * PER_WORKER) {
        db.cache_accessed(&format!("k{}.b0", i % 5000), i as i64)
            .unwrap();
    }
    let serial = t.elapsed();

    let total = WORKERS * PER_WORKER;
    println!(
        "B5: {total} LRU touches — {WORKERS} threads {concurrent:?}, 1 thread {serial:?} \
         (per-op {:?} vs {:?})",
        concurrent / total as u32,
        serial / total as u32
    );
}

#[test]
fn test_db_has_children_and_trashed_filtering() {
    use proton_drive_rs::proton_sdk::ids::{LinkId, VolumeId};
    let db = Db::open_in_memory().unwrap();
    let parent_uid = NodeUid::new(VolumeId::from("vol"), LinkId::from("parent"));
    let child_uid = NodeUid::new(VolumeId::from("vol"), LinkId::from("child"));

    assert!(
        !db.has_children(&parent_uid).unwrap(),
        "no children initially"
    );

    let parent_node = Node {
        uid: parent_uid.clone(),
        parent_uid: None,
        name: "parent".into(),
        kind: NodeKind::Folder,
        creation_time: 100,
        modification_time: 100,
        trashed: false,
        is_shared: false,
        is_shared_publicly: false,
        signature_email: None,
        membership: None,
        photo: None,
        album: None,
        verification: Default::default(),
        direct_role: None,
        share_id: None,
    };
    db.upsert_node(&parent_node).unwrap();

    let mut child_node = Node {
        uid: child_uid.clone(),
        parent_uid: Some(parent_uid.clone()),
        name: "child.txt".into(),
        kind: NodeKind::File {
            media_type: "text/plain".into(),
            total_size_on_storage: 10,
            active_revision_state: None,
            active_revision_id: None,
            content_sha1: None,
            claimed_size: Some(10),
            claimed_modification_time: None,
        },
        creation_time: 100,
        modification_time: 100,
        trashed: false,
        is_shared: false,
        is_shared_publicly: false,
        signature_email: None,
        membership: None,
        photo: None,
        album: None,
        verification: Default::default(),
        direct_role: None,
        share_id: None,
    };
    db.upsert_node(&child_node).unwrap();

    assert!(db.has_children(&parent_uid).unwrap(), "child node present");

    // Trashing child removes it from active children
    child_node.trashed = true;
    db.upsert_node(&child_node).unwrap();

    assert!(
        !db.has_children(&parent_uid).unwrap(),
        "trashed child ignored"
    );
}

#[test]
fn test_db_has_create_op() {
    let db = Db::open_in_memory().unwrap();
    let local_uid = "local~testnode12345678901234567890";

    assert!(!db.has_create_op(local_uid).unwrap(), "no op initially");

    let op = ops::PendingOp {
        id: 0,
        kind: ops::OP_CREATE.to_string(),
        uid: local_uid.to_string(),
        parent_uid: Some("vol~parent".to_string()),
        name: Some("test.txt".to_string()),
        blob_path: None,
        meta_json: None,
        created_at: 1000,
        attempts: 0,
        last_error: None,
        next_attempt_at: 0,
    };
    db.enqueue_op(&op).unwrap();

    assert!(db.has_create_op(local_uid).unwrap(), "create op present");

    db.delete_ops_for_uid(local_uid).unwrap();
    assert!(!db.has_create_op(local_uid).unwrap(), "op deleted");
}

/// The album listing is a wholesale replacement, and an album that leaves the
/// listing must take its contents with it — nothing else ever deletes those rows.
#[test]
fn albums_replace_drops_the_contents_of_an_album_that_left() {
    let db = Db::open_in_memory().unwrap();
    let album = |uid: &str, name: &str, activity: Option<i64>| StoredAlbum {
        uid: uid.into(),
        name: name.into(),
        photo_count: 2,
        cover_uid: Some("cover".into()),
        last_activity: activity,
        shared: false,
    };
    db.albums_replace(&[
        album("a1", "Trip", Some(500)),
        album("a2", "Cats", Some(400)),
    ])
    .unwrap();
    db.album_photos_replace("a1", &[("p1".into(), 300, None, None)])
        .unwrap();
    db.album_photos_replace("a2", &[("p2".into(), 200, None, None)])
        .unwrap();

    // The next refresh no longer has a2 — it was deleted, or unshared.
    db.albums_replace(&[album("a1", "Trip", Some(600))])
        .unwrap();

    assert_eq!(db.albums_count().unwrap(), 1);
    assert_eq!(db.album_photos_count("a1").unwrap(), 1);
    assert_eq!(
        db.album_photos_count("a2").unwrap(),
        0,
        "a departed album's photos go with it"
    );
}

/// An album's contents are replaced like the timeline: server order is kept, and
/// what a thumbnail attempt cost a download to learn survives the refresh.
#[test]
fn album_photos_replace_keeps_what_was_learned() {
    let db = Db::open_in_memory().unwrap();
    db.albums_replace(&[StoredAlbum {
        uid: "a1".into(),
        name: "Trip".into(),
        photo_count: 3,
        cover_uid: None,
        last_activity: None,
        shared: true,
    }])
    .unwrap();
    db.album_photos_replace(
        "a1",
        &[
            ("p1".into(), 300, None, Some("video/mp4".into())),
            ("p2".into(), 200, None, None),
        ],
    )
    .unwrap();

    db.album_photo_set_thumb("p1", THUMB_HAVE, Some(1.5))
        .unwrap();
    db.album_photo_set_thumb("p2", THUMB_NONE, None).unwrap();

    db.album_photos_replace(
        "a1",
        &[
            ("p0".into(), 400, Some("new.jpg".into()), None),
            ("p1".into(), 300, None, None),
            ("p2".into(), 200, None, None),
        ],
    )
    .unwrap();

    let page = db.album_photos_page("a1", 0, 10).unwrap();
    assert_eq!(
        page.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["p0", "p1", "p2"],
        "the album's own order is preserved"
    );
    assert_eq!(page[1].ratio, Some(1.5));
    assert_eq!(page[1].thumb_state, THUMB_HAVE);
    assert_eq!(page[2].thumb_state, THUMB_NONE);
    // The media type is learned-and-kept, so p1 stays classified as a video even
    // though the second refresh carried none.
    assert_eq!(page[1].kind, crate::control::PhotoKind::Video);
    assert_eq!(page[0].thumb_state, THUMB_UNKNOWN);

    // Paging is relative to the album, and the shared flag round-trips.
    let second = db.album_photos_page("a1", 1, 1).unwrap();
    assert_eq!(second.len(), 1);
    assert_eq!(second[0].uid, "p1");
    assert!(db.albums_list().unwrap()[0].shared);
}

/// A photo held only by an album — everything in an album shared with us — is
/// still resolvable for its capture time, which is what tags its cached
/// thumbnail. One row per uid, even when the photo is in several albums.
#[test]
fn album_photos_by_uid_resolves_a_photo_outside_the_timeline() {
    let db = Db::open_in_memory().unwrap();
    db.album_photos_replace("a1", &[("p1".into(), 300, None, None)])
        .unwrap();
    db.album_photos_replace("a2", &[("p1".into(), 300, None, None)])
        .unwrap();

    let found = db
        .album_photos_by_uid(&["p1".into(), "absent".into()])
        .unwrap();
    assert_eq!(found.len(), 1, "a photo in two albums resolves once");
    assert_eq!(found[0].capture_time, 300);
    assert!(db.album_photos_by_uid(&[]).unwrap().is_empty());
}

/// Per-album freshness stamps are keyed by uid, so invalidating them all is a
/// prefix sweep — and it must not take unrelated keys with it.
#[test]
fn clear_state_prefix_takes_only_the_prefixed_keys() {
    let db = Db::open_in_memory().unwrap();
    db.set_state_i64("album_synced_ms:vol~a1", 1).unwrap();
    db.set_state_i64("album_synced_ms:vol~a2", 2).unwrap();
    db.set_state_i64("albums_synced_ms", 3).unwrap();

    db.clear_state_prefix("album_synced_ms:").unwrap();

    assert_eq!(db.state_i64("album_synced_ms:vol~a1").unwrap(), None);
    assert_eq!(db.state_i64("album_synced_ms:vol~a2").unwrap(), None);
    assert_eq!(
        db.state_i64("albums_synced_ms").unwrap(),
        Some(3),
        "the listing's own stamp is not a per-album one"
    );
}

// --- `nodes.path`, and the subtree work it replaces (DB3) -------------------

/// Read the stored path column directly: the point of these tests is that the
/// column itself is right, not that `path_of` can still fall back to a walk.
fn stored_path(db: &Db, link: &str) -> Option<String> {
    use rusqlite::OptionalExtension;
    db.with_conn(|conn| {
        Ok(conn
            .query_row(
                "SELECT path FROM nodes WHERE uid = ?1",
                [uid(link).to_string()],
                |row| row.get::<_, Option<String>>(0),
            )
            .optional()?
            .flatten())
    })
    .unwrap()
}

#[test]
fn a_node_stores_its_path_when_it_is_written() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("docs", Some("root"), "Documents"))
        .unwrap();
    db.upsert_node(&file("f1", "docs", "report.pdf", 1))
        .unwrap();

    // The root's name is the mount, so it contributes nothing.
    assert_eq!(stored_path(&db, "root").as_deref(), Some(""));
    assert_eq!(stored_path(&db, "docs").as_deref(), Some("Documents"));
    assert_eq!(
        stored_path(&db, "f1").as_deref(),
        Some("Documents/report.pdf")
    );
}

#[test]
fn a_node_below_an_uncached_parent_starts_its_own_path() {
    // A device folder's root lives in `device`/`sync_folder` and never gets a
    // `nodes` row, so its children are the top of the cached chain.
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("orphan", Some("never-cached"), "Work"))
        .unwrap();
    db.upsert_node(&file("f1", "orphan", "notes.txt", 1))
        .unwrap();

    assert_eq!(stored_path(&db, "orphan").as_deref(), Some("Work"));
    assert_eq!(stored_path(&db, "f1").as_deref(), Some("Work/notes.txt"));
}

#[test]
fn renaming_a_folder_rewrites_every_descendant_path() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("a", Some("root"), "Before"))
        .unwrap();
    db.upsert_node(&folder("b", Some("a"), "Inner")).unwrap();
    db.upsert_node(&file("f1", "b", "deep.txt", 1)).unwrap();
    assert_eq!(
        stored_path(&db, "f1").as_deref(),
        Some("Before/Inner/deep.txt")
    );

    db.upsert_node(&folder("a", Some("root"), "After")).unwrap();

    assert_eq!(stored_path(&db, "a").as_deref(), Some("After"));
    assert_eq!(stored_path(&db, "b").as_deref(), Some("After/Inner"));
    assert_eq!(
        stored_path(&db, "f1").as_deref(),
        Some("After/Inner/deep.txt")
    );
    let hit = &db.search("deep.txt", 10).unwrap()[0];
    assert_eq!(
        hit.path, "After/Inner/deep.txt",
        "the search index must carry the rewritten path too"
    );
}

#[test]
fn moving_a_folder_rewrites_every_descendant_path() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("old", Some("root"), "Old")).unwrap();
    db.upsert_node(&folder("new", Some("root"), "New")).unwrap();
    db.upsert_node(&folder("moved", Some("old"), "Moved"))
        .unwrap();
    db.upsert_node(&file("f1", "moved", "deep.txt", 1)).unwrap();

    db.upsert_node(&folder("moved", Some("new"), "Moved"))
        .unwrap();

    assert_eq!(stored_path(&db, "moved").as_deref(), Some("New/Moved"));
    assert_eq!(
        stored_path(&db, "f1").as_deref(),
        Some("New/Moved/deep.txt")
    );
}

#[test]
fn trashing_a_folder_drops_its_subtree_from_the_index() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&folder("a", Some("root"), "Holder"))
        .unwrap();
    db.upsert_node(&file("f1", "a", "hidden.txt", 1)).unwrap();
    assert_eq!(db.search("hidden", 10).unwrap().len(), 1);

    let mut trashed = folder("a", Some("root"), "Holder");
    trashed.trashed = true;
    db.upsert_node(&trashed).unwrap();

    assert_eq!(
        db.search("hidden", 10).unwrap().len(),
        0,
        "a file under a trashed folder is not reachable and must not be findable"
    );

    // …and comes back when the folder does.
    db.upsert_node(&folder("a", Some("root"), "Holder"))
        .unwrap();
    assert_eq!(db.search("hidden", 10).unwrap().len(), 1);
}

/// The re-listing case, which is most of what the write path actually does: a
/// folder upserted with the same name and parent must not touch its subtree.
///
/// Written as a ratio between two subtree sizes, so it fails on the scaling
/// regression rather than on a slow machine. Before this, every re-listing paid
/// a `path_of` walk plus an ancestor walk per descendant.
#[test]
fn re_listing_a_folder_does_not_scale_with_its_subtree() {
    fn elapsed_for(children: usize) -> std::time::Duration {
        let db = Db::open_in_memory().unwrap();
        db.upsert_node(&folder("root", None, "My Files")).unwrap();
        db.upsert_node(&folder("big", Some("root"), "Big")).unwrap();
        let kids: Vec<Node> = (0..children)
            .map(|i| file(&format!("k{i}"), "big", &format!("child-{i}.txt"), 1))
            .collect();
        db.upsert_nodes(&kids).unwrap();

        let unchanged = folder("big", Some("root"), "Big");
        let start = std::time::Instant::now();
        for _ in 0..20 {
            db.upsert_node(&unchanged).unwrap();
        }
        start.elapsed()
    }

    let small = elapsed_for(100);
    let large = elapsed_for(2_000);
    assert!(
        large < small * 8,
        "re-listing a folder scaled with its subtree: {small:?} for 100 children, \
         {large:?} for 2000 (20x the descendants)"
    );
}

#[test]
fn migration_v25_backfills_paths_for_an_existing_tree() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-v24-fixture-{}-{}.db",
        std::process::id(),
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos()
    ));
    {
        let db = Db::open(&path).unwrap();
        db.upsert_node(&folder("root", None, "My Files")).unwrap();
        db.upsert_node(&folder("docs", Some("root"), "Documents"))
            .unwrap();
        db.upsert_node(&file("f1", "docs", "report.pdf", 1))
            .unwrap();
        db.upsert_node(&folder("orphan", Some("never-cached"), "Work"))
            .unwrap();
        db.upsert_node(&file("f2", "orphan", "notes.txt", 1))
            .unwrap();
    }
    {
        // Put the file back in the state a released V24 database was in.
        let conn = rusqlite::Connection::open(&path).unwrap();
        conn.execute_batch(
            "ALTER TABLE nodes DROP COLUMN path;
             UPDATE sync_state SET value = '24' WHERE key = 'schema_version';",
        )
        .unwrap();
    }

    let db = Db::open(&path).unwrap();
    assert_eq!(stored_path(&db, "root").as_deref(), Some(""));
    assert_eq!(stored_path(&db, "docs").as_deref(), Some("Documents"));
    assert_eq!(
        stored_path(&db, "f1").as_deref(),
        Some("Documents/report.pdf"),
        "an existing tree must come out of the migration with the same paths \
         the walk used to produce"
    );
    // A subtree whose top has an uncached parent is ordinary data, not an error.
    assert_eq!(stored_path(&db, "orphan").as_deref(), Some("Work"));
    assert_eq!(stored_path(&db, "f2").as_deref(), Some("Work/notes.txt"));

    let _ = std::fs::remove_file(&path);
    let _ = std::fs::remove_file(format!("{}.lock", path.display()));
}

/// A queue carried over from V26 keeps its rows, and every one of them starts
/// out not access-deferred — a migration must not invent a deferral window that
/// would report an ordinary queued upload as blocked.
#[test]
fn migration_v27_adds_the_access_deferral_column_to_a_v26_queue() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-v26-fixture-{}-{}.db",
        std::process::id(),
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos()
    ));
    {
        let db = Db::open(&path).unwrap();
        db.enqueue_op(&crate::db::PendingOp {
            id: 0,
            kind: crate::db::OP_REVISION.to_string(),
            uid: "v~l".to_string(),
            parent_uid: None,
            name: None,
            blob_path: Some("/tmp/blob".to_string()),
            meta_json: Some("{}".to_string()),
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap();
    }
    {
        // Put the file back in the state a released V26 database was in.
        let conn = rusqlite::Connection::open(&path).unwrap();
        conn.execute_batch(
            "ALTER TABLE pending_op DROP COLUMN access_deferred_since;
             UPDATE sync_state SET value = '26' WHERE key = 'schema_version';",
        )
        .unwrap();
    }

    let db = Db::open(&path).unwrap();
    let ops = db.pending_ops().unwrap();
    assert_eq!(ops.len(), 1, "the migration keeps the queued write");
    let now = 5_000i64;
    assert_eq!(
        db.defer_op_for_access(ops[0].id, now, now + 5_000).unwrap(),
        now,
        "a carried-over op is not already deferred"
    );

    let _ = std::fs::remove_file(&path);
    let _ = std::fs::remove_file(format!("{}.lock", path.display()));
}

/// V44 adds the remote revision a baseline row was synced at. A row carried
/// over from V43 has none, and the mirror then compares the modification time
/// and size as before, so upgrading changes nothing about what is in step
/// (`docs/BUGS.md` B249).
#[test]
fn migration_v44_adds_the_synced_revision_without_disturbing_a_v43_baseline() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-v43-fixture-{}-{}.db",
        std::process::id(),
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos()
    ));
    let row = StoredSyncEntry {
        rel_path: "notes.txt".into(),
        remote_uid: Some("vol~notes".into()),
        local_mtime: 1_700_000_000,
        local_mtime_ns: Some(1_700_000_000_123_456_789),
        local_size: 42,
        remote_rev: Some("1700000000".into()),
        remote_hash: Some("42".into()),
        remote_revision_id: Some("rev-1".into()),
    };
    {
        let db = Db::open(&path).unwrap();
        let folder = db
            .sync_folder_add("/home/me/Mirror", "vol~root", "share")
            .unwrap();
        db.sync_entry_upsert(folder, &row).unwrap();
    }
    {
        // Put the file back in the state a released V43 database was in.
        let conn = rusqlite::Connection::open(&path).unwrap();
        conn.execute_batch(
            "ALTER TABLE sync_entry DROP COLUMN remote_revision_id;
             UPDATE sync_state SET value = '43' WHERE key = 'schema_version';",
        )
        .unwrap();
    }

    let db = Db::open(&path).unwrap();
    let entries = db.sync_entries(1).unwrap();
    let entry = entries.get("notes.txt").expect("the baseline row survives");
    assert_eq!(
        entry,
        &StoredSyncEntry {
            remote_revision_id: None,
            ..row.clone()
        }
    );

    // And the column is live, including through a move of the row.
    db.sync_entry_upsert(1, &row).unwrap();
    db.sync_entries_move(1, "notes.txt", 1, "moved.txt")
        .unwrap();
    let entries = db.sync_entries(1).unwrap();
    assert_eq!(
        entries["moved.txt"].remote_revision_id.as_deref(),
        Some("rev-1")
    );
    drop(db);
    let _ = std::fs::remove_file(&path);
}

/// A mirror baseline carried over from V27 keeps its rows, and each one reads
/// back with no nanosecond time. That `None` is the whole point: it makes the
/// comparison fall back to whole seconds for rows written before the column
/// existed, instead of asserting a sub-second time of zero and re-uploading
/// every already-synced file in the folder (`docs/BUGS.md` B25).
#[test]
fn migration_v28_adds_sub_second_local_times_without_disturbing_a_v27_baseline() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-v27-fixture-{}-{}.db",
        std::process::id(),
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos()
    ));
    {
        let db = Db::open(&path).unwrap();
        let folder = db
            .sync_folder_add("/home/me/Mirror", "vol~root", "share")
            .unwrap();
        db.sync_entry_upsert(
            folder,
            &StoredSyncEntry {
                rel_path: "notes.txt".into(),
                remote_uid: Some("vol~notes".into()),
                local_mtime: 1_700_000_000,
                local_mtime_ns: Some(1_700_000_000_123_456_789),
                local_size: 42,
                remote_rev: Some("1700000000".into()),
                remote_hash: Some("42".into()),
                remote_revision_id: None,
            },
        )
        .unwrap();
    }
    {
        // Put the file back in the state a released V27 database was in.
        let conn = rusqlite::Connection::open(&path).unwrap();
        conn.execute_batch(
            "ALTER TABLE sync_entry DROP COLUMN local_mtime_ns;
             UPDATE sync_state SET value = '27' WHERE key = 'schema_version';",
        )
        .unwrap();
    }

    let db = Db::open(&path).unwrap();
    let entries = db.sync_entries(1).unwrap();
    let entry = entries.get("notes.txt").expect("the baseline row survives");
    assert_eq!(entry.local_mtime, 1_700_000_000);
    assert_eq!(entry.local_size, 42);
    assert_eq!(
        entry.local_mtime_ns, None,
        "a carried-over row must not claim a sub-second time it never recorded"
    );

    // And the column is live: a refreshed row keeps the precision it is given.
    db.sync_entry_upsert(
        1,
        &StoredSyncEntry {
            local_mtime_ns: Some(1_700_000_001_000_000_500),
            ..entry.clone()
        },
    )
    .unwrap();
    assert_eq!(
        db.sync_entries(1).unwrap()["notes.txt"].local_mtime_ns,
        Some(1_700_000_001_000_000_500)
    );

    let _ = std::fs::remove_file(&path);
    let _ = std::fs::remove_file(format!("{}.lock", path.display()));
}

// --- read-only connection pool (DB2) ---------------------------------------

/// A read must not queue behind whatever happens to be writing.
///
/// The write connection is held for the whole measurement — which is what a
/// large listing's commit does to it — while a reader asks for a search. Before
/// the pool this was the same mutex, so the read waited for the writer;
/// `busy_timeout` never entered into it, because the contention was this
/// process's own lock rather than SQLite's.
#[test]
fn a_read_does_not_wait_for_the_write_connection() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-readpool-{}-{}.db",
        std::process::id(),
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos()
    ));
    let db = std::sync::Arc::new(Db::open(&path).unwrap());
    db.upsert_node(&folder("root", None, "My Files")).unwrap();
    db.upsert_node(&file("f1", "root", "findme.txt", 1))
        .unwrap();

    let held = std::time::Duration::from_millis(500);
    let (tx, rx) = std::sync::mpsc::channel();
    let writer = {
        let db = db.clone();
        std::thread::spawn(move || {
            db.with_conn(|_conn| {
                tx.send(()).unwrap();
                std::thread::sleep(held);
                Ok(())
            })
            .unwrap();
        })
    };
    rx.recv().unwrap();

    let start = std::time::Instant::now();
    let hits = db.search("findme", 10).unwrap();
    let waited = start.elapsed();
    writer.join().unwrap();

    assert_eq!(hits.len(), 1, "the read must still see committed data");
    assert!(
        waited < held / 2,
        "the read waited {waited:?} for a write connection held {held:?}"
    );

    drop(db);
    let _ = std::fs::remove_file(&path);
    let _ = std::fs::remove_file(format!("{}.lock", path.display()));
}

/// §5: the drain is several workers over one queue, and the claim column is the
/// only thing keeping them off each other's work. Two properties matter — no
/// row is ever handed to two workers, and no *node* is ever worked by two
/// workers even though its ops are separate rows.
#[test]
fn a_claimed_op_is_invisible_to_every_other_worker() {
    let db = Db::open_in_memory().unwrap();
    let root = uid("root").to_string();
    for i in 0..3 {
        db.enqueue_op(&bulk_op(i, &root)).unwrap();
    }

    let first = db.claim_next_due_op(10).unwrap().expect("an op is due");
    let second = db
        .claim_next_due_op(10)
        .unwrap()
        .expect("another op is due");
    let third = db
        .claim_next_due_op(10)
        .unwrap()
        .expect("a third op is due");
    assert!(
        db.claim_next_due_op(10).unwrap().is_none(),
        "a fourth claim must find nothing left: every queued op is taken"
    );

    let mut ids = [first.id, second.id, third.id];
    ids.sort_unstable();
    assert_eq!(
        ids,
        [1, 2, 3],
        "each worker must get a distinct row, oldest first"
    );

    // Releasing puts one back, and it is the one that comes out next.
    db.release_op_claim(second.id).unwrap();
    let again = db.claim_next_due_op(10).unwrap().expect("the released op");
    assert_eq!(again.id, second.id);
}

#[test]
fn two_workers_never_share_a_node() {
    let db = Db::open_in_memory().unwrap();
    let root = uid("root").to_string();
    // Two ops of different kinds against one node — a queued rename and a
    // queued revision, which is an ordinary `mv` plus a save.
    let mut revision = bulk_op(0, &root);
    revision.parent_uid = None;
    db.enqueue_op(&revision).unwrap();
    let rename = PendingOp {
        kind: OP_RENAME.to_string(),
        parent_uid: Some(root.clone()),
        blob_path: None,
        meta_json: None,
        ..bulk_op(0, &root)
    };
    db.enqueue_op(&rename).unwrap();

    let claimed = db.claim_next_due_op(10).unwrap().expect("an op is due");
    assert_eq!(claimed.kind, OP_REVISION, "the older op goes first");
    assert!(
        db.claim_next_due_op(10).unwrap().is_none(),
        "the second op targets the same node, so it must wait for the first: \
         two workers on one uid would race over its staged blob and land its \
         changes out of order"
    );

    db.release_op_claim(claimed.id).unwrap();
    db.delete_op(claimed.id).unwrap();
    assert_eq!(
        db.claim_next_due_op(10).unwrap().map(|o| o.kind),
        Some(OP_RENAME.to_string()),
        "once the revision retires, the rename is claimable"
    );
}

#[test]
fn claims_do_not_survive_the_process_that_took_them() {
    let db = Db::open_in_memory().unwrap();
    let root = uid("root").to_string();
    for i in 0..2 {
        db.enqueue_op(&bulk_op(i, &root)).unwrap();
    }
    db.claim_next_due_op(10).unwrap().unwrap();
    db.claim_next_due_op(10).unwrap().unwrap();
    assert!(db.claim_next_due_op(10).unwrap().is_none());

    // What `Db::open` does after the single-writer lock says the previous run
    // is gone. Without it those ops are invisible to every worker forever.
    assert_eq!(db.clear_op_claims().unwrap(), 2);
    assert!(
        db.claim_next_due_op(10).unwrap().is_some(),
        "a crashed run's claims must not park its queue"
    );
}

#[test]
fn an_idle_worker_does_not_wait_on_an_op_another_worker_has() {
    let db = Db::open_in_memory().unwrap();
    let root = uid("root").to_string();
    db.enqueue_op(&bulk_op(0, &root)).unwrap();

    assert_eq!(db.earliest_due_at().unwrap(), Some(0));
    db.claim_next_due_op(10).unwrap().unwrap();
    assert_eq!(
        db.earliest_due_at().unwrap(),
        None,
        "an op somebody else is draining is not work this worker is waiting for"
    );
}

/// B200: a rename queued behind a long upload of the same node is due, but no
/// worker may claim it until the upload retires. Counted as due, it had every
/// idle worker wake at once, find nothing, and go round again.
#[test]
fn earliest_due_at_skips_an_op_held_behind_a_claimed_one() {
    let db = Db::open_in_memory().unwrap();
    let root = uid("root").to_string();
    let mut revision = bulk_op(0, &root);
    revision.parent_uid = None;
    db.enqueue_op(&revision).unwrap();
    db.enqueue_op(&PendingOp {
        kind: OP_RENAME.to_string(),
        parent_uid: Some(root.clone()),
        blob_path: None,
        meta_json: None,
        ..bulk_op(0, &root)
    })
    .unwrap();

    db.claim_next_due_op(10)
        .unwrap()
        .expect("the revision is due");
    assert!(db.claim_next_due_op(10).unwrap().is_none());
    assert_eq!(
        db.earliest_due_at().unwrap(),
        None,
        "a row no worker can claim is not work an idle worker is waiting for"
    );
}

/// Trashing a photo from the gallery must not leave it behind on an album page:
/// the row goes, its album membership goes with it, and nothing else moves.
#[test]
fn photos_delete_removes_the_photo_and_its_album_membership() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow::new("p1", 300),
        TimelineRow::new("p2", 200),
        TimelineRow::new("p3", 100),
    ])
    .unwrap();
    db.albums_replace(&[StoredAlbum {
        uid: "a1".into(),
        name: "Trip".into(),
        photo_count: 3,
        cover_uid: Some("p1".into()),
        last_activity: Some(500),
        shared: false,
    }])
    .unwrap();
    db.album_photos_replace(
        "a1",
        &[
            ("p1".into(), 300, None, None),
            ("p2".into(), 200, None, None),
            ("p3".into(), 100, None, None),
        ],
    )
    .unwrap();

    assert_eq!(db.photos_delete(&["p2".into()]).unwrap(), 1);

    let page = db.photos_page(0, 10, None, None, false, false).unwrap();
    assert_eq!(
        page.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["p1", "p3"],
        "only the trashed photo leaves the timeline"
    );
    assert_eq!(db.album_photos_count("a1").unwrap(), 2);
    let album = db.album_photos_page("a1", 0, 10).unwrap();
    assert_eq!(
        album.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["p1", "p3"]
    );

    // A uid we no longer hold is not an error: the event poller and the trash
    // reply can both report the same deletion.
    assert_eq!(db.photos_delete(&["p2".into()]).unwrap(), 0);
    assert_eq!(db.photos_delete(&[]).unwrap(), 0);
}

/// A shot taken as RAW+JPEG is one photo to the person who took it: the grid
/// shows the JPEG once, and the Raw tab still lists the raw file.
#[test]
fn a_raw_and_its_jpeg_are_one_entry_in_the_grid() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow {
            name: Some("IMG_1234.JPG".into()),
            ..TimelineRow::new("jpeg", 300)
        },
        TimelineRow {
            name: Some("img_1234.cr2".into()),
            ..TimelineRow::new("raw", 300)
        },
        TimelineRow {
            name: Some("IMG_9999.JPG".into()),
            ..TimelineRow::new("alone", 200)
        },
    ])
    .unwrap();

    let page = db.photos_page(0, 10, None, None, false, false).unwrap();
    assert_eq!(
        page.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["jpeg", "alone"],
        "the pair shows once, as the member that can be displayed"
    );
    assert_eq!(page[0].group_size, 2);
    assert!(page[0].has_raw, "the tile can say the raw is there");
    assert_eq!(page[1].group_size, 1);
    assert!(!page[1].has_raw);

    // The Raw tab answers "which raws do I have", so it lists files.
    let raws = db
        .photos_page(
            0,
            10,
            Some(crate::control::PhotoKind::Raw),
            None,
            false,
            false,
        )
        .unwrap();
    assert_eq!(
        raws.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["raw"]
    );
    assert_eq!(db.photos_counts().unwrap(), (2, 0, 1));

    // Both members are reachable from either uid: the lightbox switches between
    // them, and deleting the tile has to trash both.
    let group = db.photos_group("raw").unwrap();
    assert_eq!(
        group.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["jpeg", "raw"]
    );
    assert_eq!(db.photos_group("alone").unwrap().len(), 1);
}

/// Pixel names the two files of one raw capture after the role each plays, so
/// their stems differ. The shot is still one shot, and the grid shows the cover
/// JPEG.
#[test]
fn a_pixel_raw_capture_groups_with_its_cover_jpeg() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow {
            name: Some("PXL_20260919_000625670.RAW-01.COVER.jpg".into()),
            ..TimelineRow::new("cover", 1_789_776_385)
        },
        TimelineRow {
            name: Some("PXL_20260919_000625670.RAW-02.ORIGINAL.dng".into()),
            ..TimelineRow::new("original", 1_789_776_385)
        },
        // A name that merely contains the marker's opening is not a marker.
        TimelineRow {
            name: Some("scan.raw-notes.jpg".into()),
            ..TimelineRow::new("notes", 1_789_776_385)
        },
        TimelineRow {
            name: Some("scan.raw-other.dng".into()),
            ..TimelineRow::new("other", 1_789_776_385)
        },
    ])
    .unwrap();

    let page = db.photos_page(0, 10, None, None, false, false).unwrap();
    assert_eq!(
        page.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["cover", "notes", "other"],
        "the capture shows once, as the cover JPEG"
    );
    assert_eq!(page[0].group_size, 2);
    assert!(page[0].has_raw);
    assert_eq!(
        db.photos_group("original")
            .unwrap()
            .iter()
            .map(|p| p.uid.as_str())
            .collect::<Vec<_>>(),
        ["cover", "original"]
    );
}

/// Two files that merely share a name are not one shot: the same stem on
/// different days, or two files of the same kind, stay apart.
#[test]
fn a_shared_name_alone_does_not_group_photos() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow {
            name: Some("IMG_1234.JPG".into()),
            ..TimelineRow::new("today", 1_700_000_000)
        },
        TimelineRow {
            name: Some("IMG_1234.CR2".into()),
            ..TimelineRow::new("last-year", 1_600_000_000)
        },
        TimelineRow {
            name: Some("IMG_1234.PNG".into()),
            ..TimelineRow::new("same-kind", 1_700_000_000)
        },
    ])
    .unwrap();

    let page = db.photos_page(0, 10, None, None, false, false).unwrap();
    assert_eq!(page.len(), 3, "three shots, three tiles");
    assert!(page.iter().all(|p| p.group_size == 1));
}

/// The server knows about live photos and bursts, so its own relation groups
/// files this client would never pair by name.
#[test]
fn the_servers_photo_relation_groups_a_live_photo() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow {
            name: Some("IMG_0001.HEIC".into()),
            ..TimelineRow::new("main", 300)
        },
        TimelineRow {
            name: Some("clip.mov".into()),
            main_uid: Some("main".into()),
            ..TimelineRow::new("related", 299)
        },
    ])
    .unwrap();

    let page = db.photos_page(0, 10, None, None, false, false).unwrap();
    assert_eq!(
        page.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["main"]
    );
    assert_eq!(page[0].group_size, 2);
    assert!(!page[0].has_raw, "a live photo's video is not a raw file");

    // The relation is learned-and-kept: a refresh that could not resolve the
    // nodes must not break the group up.
    db.photos_replace(&[
        TimelineRow::new("main", 300),
        TimelineRow::new("related", 299),
    ])
    .unwrap();
    assert_eq!(db.photos_group("related").unwrap().len(), 2);
}

/// A database written before grouping existed opens, keeps its timeline, and
/// shows every photo — a row with no `group_key` is its own group, which is how
/// the gallery behaved before the column.
#[test]
fn migration_v32_retries_videos_written_off_as_unthumbnailable() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-v31-fixture-{}-{}.db",
        std::process::id(),
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos()
    ));
    {
        let db = Db::open(&path).unwrap();
        db.photos_replace(&[
            TimelineRow {
                name: Some("VID-20260804-WA0023.mp4".into()),
                ..TimelineRow::new("video", 300)
            },
            TimelineRow {
                name: Some("broken.jpg".into()),
                ..TimelineRow::new("photo", 200)
            },
        ])
        .unwrap();
        db.photo_set_thumb("video", THUMB_NONE, None).unwrap();
        db.photo_set_thumb("photo", THUMB_NONE, None).unwrap();
        let conn = rusqlite::Connection::open(&path).unwrap();
        conn.execute_batch("UPDATE sync_state SET value = '31' WHERE key = 'schema_version';")
            .unwrap();
    }

    let db = Db::open(&path).unwrap();
    let state = |uid: &str| db.photos_by_uid(&[uid.into()]).unwrap()[0].thumb_state;
    assert_eq!(state("video"), THUMB_UNKNOWN, "the video is tried again");
    assert_eq!(
        state("photo"),
        THUMB_NONE,
        "an undecodable photo stays written off"
    );
    drop(db);
    let _ = std::fs::remove_file(&path);
}

#[test]
fn migration_v30_leaves_a_v29_timeline_intact() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-v29-fixture-{}-{}.db",
        std::process::id(),
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos()
    ));
    {
        let db = Db::open(&path).unwrap();
        db.photos_replace(&[
            TimelineRow {
                name: Some("IMG_1234.JPG".into()),
                ..TimelineRow::new("jpeg", 300)
            },
            TimelineRow {
                name: Some("IMG_1234.CR2".into()),
                ..TimelineRow::new("raw", 300)
            },
        ])
        .unwrap();
        db.photo_set_thumb("jpeg", THUMB_HAVE, Some(1.5)).unwrap();
    }
    {
        // Put the file back in the state a released V29 database was in.
        let conn = rusqlite::Connection::open(&path).unwrap();
        conn.execute_batch(
            "DROP INDEX idx_photos_group;
             ALTER TABLE photos DROP COLUMN group_key;
             ALTER TABLE photos DROP COLUMN main_uid;
             ALTER TABLE photos DROP COLUMN content_hash;
             UPDATE sync_state SET value = '29' WHERE key = 'schema_version';",
        )
        .unwrap();
    }

    let db = Db::open(&path).unwrap();
    let page = db.photos_page(0, 10, None, None, false, false).unwrap();
    assert_eq!(
        page.iter().map(|p| p.uid.as_str()).collect::<Vec<_>>(),
        ["jpeg", "raw"],
        "no photo goes missing before the next refresh groups them"
    );
    assert!(page.iter().all(|p| p.group_size == 1));
    assert_eq!(page[0].ratio, Some(1.5), "what was learned is still there");

    // The next refresh fills the column in and the pair collapses.
    db.photos_replace(&[
        TimelineRow {
            name: Some("IMG_1234.JPG".into()),
            ..TimelineRow::new("jpeg", 300)
        },
        TimelineRow {
            name: Some("IMG_1234.CR2".into()),
            ..TimelineRow::new("raw", 300)
        },
    ])
    .unwrap();
    let page = db.photos_page(0, 10, None, None, false, false).unwrap();
    assert_eq!(page.len(), 1);
    assert_eq!(page[0].uid, "jpeg");

    let _ = std::fs::remove_file(&path);
    let _ = std::fs::remove_file(format!("{}.lock", path.display()));
}

/// A refresh that skips an already-resolved photo sends a row carrying only the
/// uid and capture time. The name must survive that, because the tab split and
/// the grouping are both derived from it.
#[test]
fn photos_replace_keeps_a_skipped_photos_name() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow {
            name: Some("IMG_1234.JPG".into()),
            media_type: Some("image/jpeg".into()),
            resolved_at: Some(1),
            ..TimelineRow::new("jpeg", 300)
        },
        TimelineRow {
            name: Some("IMG_1234.CR2".into()),
            media_type: Some("application/octet-stream".into()),
            resolved_at: Some(1),
            ..TimelineRow::new("raw", 300)
        },
    ])
    .unwrap();
    let page = db.photos_page(0, 10, None, None, false, false).unwrap();
    assert_eq!(page.len(), 1, "one shot, two files");
    assert!(page[0].has_raw);

    // The next refresh resolves neither, because both are already resolved.
    db.photos_replace(&[TimelineRow::new("jpeg", 300), TimelineRow::new("raw", 300)])
        .unwrap();
    let page = db.photos_page(0, 10, None, None, false, false).unwrap();
    assert_eq!(page.len(), 1, "the group survives a skipped refresh");
    assert_eq!(page[0].name.as_deref(), Some("IMG_1234.JPG"));
    assert!(page[0].has_raw, "the raw file is still a raw file");
    assert_eq!(page[0].group_size, 2);
}

/// Only the photos a refresh actually read are marked resolved; the rest stay
/// eligible, so the next refresh tries them again.
#[test]
fn photos_replace_marks_only_the_rows_it_resolved() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow {
            name: Some("ok.jpg".into()),
            resolved_at: Some(1),
            ..TimelineRow::new("ok", 300)
        },
        // The chunk holding this one failed.
        TimelineRow::new("failed", 200),
    ])
    .unwrap();
    assert_eq!(db.photos_resolved().unwrap(), ["ok"]);

    // A resolved photo stays resolved across a refresh that skips it.
    db.photos_replace(&[
        TimelineRow::new("ok", 300),
        TimelineRow {
            name: Some("late.jpg".into()),
            resolved_at: Some(2),
            ..TimelineRow::new("failed", 200)
        },
    ])
    .unwrap();
    let mut resolved = db.photos_resolved().unwrap();
    resolved.sort();
    assert_eq!(resolved, ["failed", "ok"]);
}

/// What a refresh read is the truth, including what it no longer reports: a
/// photo unlinked from its main on another device leaves the group.
#[test]
fn a_resolved_replace_clears_a_relation_the_server_dropped() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow {
            name: Some("IMG_0001.HEIC".into()),
            resolved_at: Some(1),
            ..TimelineRow::new("main", 300)
        },
        TimelineRow {
            name: Some("clip.mov".into()),
            main_uid: Some("main".into()),
            resolved_at: Some(1),
            ..TimelineRow::new("related", 299)
        },
    ])
    .unwrap();
    assert_eq!(db.photos_group("related").unwrap().len(), 2);

    // Both are read again and the server no longer reports the relation.
    db.photos_replace(&[
        TimelineRow {
            name: Some("IMG_0001.HEIC".into()),
            resolved_at: Some(2),
            ..TimelineRow::new("main", 300)
        },
        TimelineRow {
            name: Some("clip.mov".into()),
            resolved_at: Some(2),
            ..TimelineRow::new("related", 299)
        },
    ])
    .unwrap();
    assert_eq!(
        db.photos_group("related").unwrap().len(),
        1,
        "an unlinked photo stands on its own"
    );
}

/// A refresh that did *not* read the nodes must not break the group up, which is
/// the older behaviour and still the one a failed resolve gets.
#[test]
fn an_unresolved_replace_keeps_a_relation() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow {
            name: Some("IMG_0001.HEIC".into()),
            resolved_at: Some(1),
            ..TimelineRow::new("main", 300)
        },
        TimelineRow {
            name: Some("clip.mov".into()),
            main_uid: Some("main".into()),
            resolved_at: Some(1),
            ..TimelineRow::new("related", 299)
        },
    ])
    .unwrap();

    db.photos_replace(&[
        TimelineRow::new("main", 300),
        TimelineRow::new("related", 299),
    ])
    .unwrap();
    assert_eq!(db.photos_group("related").unwrap().len(), 2);
}

/// A remote event names the photo it changed, and that is all it takes to have
/// the next refresh read that one node again.
#[test]
fn marking_a_photo_unresolved_makes_it_eligible_again() {
    let db = Db::open_in_memory().unwrap();
    db.photos_replace(&[
        TimelineRow {
            name: Some("a.jpg".into()),
            resolved_at: Some(1),
            ..TimelineRow::new("a", 300)
        },
        TimelineRow {
            name: Some("b.jpg".into()),
            resolved_at: Some(1),
            ..TimelineRow::new("b", 200)
        },
    ])
    .unwrap();

    assert_eq!(db.photos_mark_unresolved(&["a".to_string()]).unwrap(), 1);
    assert_eq!(db.photos_resolved().unwrap(), ["b"]);
    // A uid the timeline does not hold changes nothing.
    assert_eq!(db.photos_mark_unresolved(&["gone".to_string()]).unwrap(), 0);

    assert_eq!(db.photos_mark_all_unresolved().unwrap(), 2);
    assert!(db.photos_resolved().unwrap().is_empty());
}

/// An existing timeline opens as resolved, so upgrading does not re-read the
/// whole library once — except for the photos nothing was ever learned about.
#[test]
fn migration_v31_treats_an_existing_timeline_as_resolved() {
    let path = std::env::temp_dir().join(format!(
        "pdfs-db-v30-fixture-{}-{}.db",
        std::process::id(),
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos()
    ));
    {
        let db = Db::open(&path).unwrap();
        db.photos_replace(&[
            TimelineRow {
                name: Some("IMG_1234.JPG".into()),
                resolved_at: Some(1),
                ..TimelineRow::new("named", 300)
            },
            // A photo whose resolve had failed: nothing was ever learned.
            TimelineRow::new("nameless", 200),
        ])
        .unwrap();
    }
    {
        // Put the file back in the state a released V30 database was in.
        let conn = rusqlite::Connection::open(&path).unwrap();
        conn.execute_batch(
            "DROP INDEX idx_photos_unresolved;
             ALTER TABLE photos DROP COLUMN resolved_at;
             UPDATE sync_state SET value = '30' WHERE key = 'schema_version';",
        )
        .unwrap();
    }

    let db = Db::open(&path).unwrap();
    assert_eq!(
        db.photos_resolved().unwrap(),
        ["named"],
        "the stored timeline is trusted, a nameless row is not"
    );

    let _ = std::fs::remove_file(&path);
    let _ = std::fs::remove_file(format!("{}.lock", path.display()));
}

fn queued_op(db: &Db, uid: &str, failures: i64, next_attempt_at: i64) -> i64 {
    let (id, _) = db
        .enqueue_op(&ops::PendingOp {
            id: 0,
            kind: ops::OP_REVISION.to_string(),
            uid: uid.to_string(),
            parent_uid: None,
            name: None,
            blob_path: None,
            meta_json: None,
            created_at: 1000,
            attempts: 0,
            last_error: None,
            next_attempt_at,
        })
        .unwrap();
    for _ in 0..failures {
        db.record_op_failure(id, "boom", next_attempt_at).unwrap();
    }
    id
}

/// "Retry now" must make a backed-off op due, but never un-park a transient
/// file's op: that one waits for its finishing rename, not for time.
#[test]
fn retry_now_makes_a_backed_off_op_due_but_leaves_parked_ops_parked() {
    let db = Db::open_in_memory().unwrap();
    let backed_off = queued_op(&db, "vol~a", 3, 90_000);
    let parked = queued_op(&db, "vol~b", 0, ops::PARK_UNTIL);

    assert!(db.retry_op_now(backed_off, 5_000).unwrap());
    assert!(!db.retry_op_now(parked, 5_000).unwrap());

    let ops = db.pending_ops().unwrap();
    let due = |id: i64| ops.iter().find(|op| op.id == id).unwrap().next_attempt_at;
    assert_eq!(due(backed_off), 5_000);
    assert_eq!(due(parked), ops::PARK_UNTIL);
}

/// A change Drive refused needs the user now, not after six more failures, and
/// its refusal is the error the status leads with.
#[test]
fn an_op_with_an_issue_counts_as_failing_at_once() {
    let db = Db::open_in_memory().unwrap();
    queued_op(&db, "vol~a", 1, 90_000);
    let refused = queued_op(&db, "vol~b", 1, 90_000);
    assert_eq!(db.pending_op_counts().unwrap().failing, 0);

    db.record_op_failure(refused, "storage quota exceeded", 90_000)
        .unwrap();
    db.set_op_issue(refused, Some("quota")).unwrap();
    let counts = db.pending_op_counts().unwrap();
    assert_eq!(counts.failing, 1);
    assert_eq!(counts.last_error.as_deref(), Some("storage quota exceeded"));
    assert_eq!(
        db.op_issues().unwrap(),
        std::collections::HashMap::from([(refused, "quota".to_string())])
    );

    // The op stays queued with its bytes; clearing the issue is all it takes.
    db.set_op_issue(refused, None).unwrap();
    assert_eq!(db.pending_op_counts().unwrap().failing, 0);
    assert!(db.op_issues().unwrap().is_empty());
    assert_eq!(db.pending_ops().unwrap().len(), 2);
}

/// The browser shows an issue on the node it is about, which it knows by
/// local id, under either uid.
#[test]
fn a_refused_change_names_its_node_by_local_id() {
    let db = Db::open_in_memory().unwrap();
    db.upsert_nodes(&[
        folder("root", None, "My Files"),
        file("a", "root", "a.bin", 1),
        file("b", "root", "b.bin", 1),
    ])
    .unwrap();
    let refused = queued_op(&db, &uid("a").to_string(), 1, 90_000);
    queued_op(&db, &uid("b").to_string(), 1, 90_000);
    let gone = queued_op(&db, "vol~nowhere", 1, 90_000);
    db.set_op_issue(refused, Some("quota")).unwrap();
    db.set_op_issue(gone, Some("missing")).unwrap();

    let lid = db.lid_of(&uid("a").to_string()).unwrap().unwrap();
    assert_eq!(
        db.node_issues().unwrap(),
        std::collections::HashMap::from([(lid, "quota".to_string())])
    );
}

/// The name checks the drain makes before each op look the name up in an
/// index. Scanning the queue instead made a large offline batch quadratic.
#[test]
fn queue_name_checks_use_an_index() {
    let db = Db::open_in_memory().unwrap();
    let conn = db.conn.lock();
    let plan = |sql: &str| -> String {
        let mut stmt = conn.prepare(&format!("EXPLAIN QUERY PLAN {sql}")).unwrap();
        stmt.query_map([], |r| r.get::<_, String>(3))
            .unwrap()
            .map(|row| row.unwrap())
            .collect::<Vec<_>>()
            .join("; ")
    };
    for sql in [
        "SELECT 1 FROM pending_op WHERE kind = 'trash' AND name = 'a'",
        "SELECT 1 FROM pending_op WHERE name = 'a' AND kind IN ('create', 'mkdir', 'rename')",
        "SELECT 1 FROM pending_op WHERE kind = 'rename'",
    ] {
        let plan = plan(sql);
        assert!(plan.contains("pending_op_kind_name"), "{sql}: {plan}");
    }
}

/// A reconnect moves up the ops that failed for want of a link. One Drive
/// refused, for quota or access, keeps its backoff: the link coming back
/// changes nothing about it. "Retry all" still moves both.
#[test]
fn a_reconnect_leaves_refused_ops_to_their_backoff() {
    let db = Db::open_in_memory().unwrap();
    let offline = queued_op(&db, "vol~a", 2, 90_000);
    let refused = queued_op(&db, "vol~b", 2, 90_000);
    db.set_op_issue(refused, Some("quota")).unwrap();

    assert_eq!(db.retry_unrefused_ops_now(5_000).unwrap(), 1);
    let due = |id: i64| {
        db.pending_ops()
            .unwrap()
            .into_iter()
            .find(|op| op.id == id)
            .unwrap()
            .next_attempt_at
    };
    assert_eq!(due(offline), 5_000);
    assert_eq!(due(refused), 90_000);

    assert_eq!(db.retry_failed_ops_now(5_000).unwrap(), 1);
    assert_eq!(due(refused), 5_000);
}

#[test]
fn retry_all_touches_only_ops_that_have_failed() {
    let db = Db::open_in_memory().unwrap();
    let failed = queued_op(&db, "vol~a", 2, 90_000);
    let debounced = queued_op(&db, "vol~b", 0, 7_000);
    let parked = queued_op(&db, "vol~c", 4, ops::PARK_UNTIL);

    assert_eq!(db.retry_failed_ops_now(5_000).unwrap(), 1);

    let ops = db.pending_ops().unwrap();
    let due = |id: i64| ops.iter().find(|op| op.id == id).unwrap().next_attempt_at;
    assert_eq!(due(failed), 5_000);
    assert_eq!(due(debounced), 7_000);
    assert_eq!(due(parked), ops::PARK_UNTIL);
}

#[test]
fn a_queued_op_stops_existing_once_the_node_is_deleted() {
    let db = Db::open_in_memory().unwrap();
    let (id, _) = db
        .enqueue_op(&PendingOp {
            id: 0,
            kind: OP_REVISION.to_string(),
            uid: uid("journal").to_string(),
            parent_uid: None,
            name: None,
            blob_path: Some("/staging/journal".to_string()),
            meta_json: Some("{}".to_string()),
            created_at: 1,
            attempts: 0,
            last_error: None,
            next_attempt_at: 0,
        })
        .unwrap();
    assert!(db.op_exists(id).unwrap());

    let blobs = db.delete_ops_for_uid(&uid("journal").to_string()).unwrap();
    assert_eq!(blobs, vec!["/staging/journal"]);
    assert!(!db.op_exists(id).unwrap());
}