feat(core,fuse): group the RAW and the JPEG of one shot

A camera that writes both puts two files on the volume, and the timeline showed
two tiles of the same photo. They are one shot to the person who took it.

Schema v30 records what ties them together: the server's own duplicate hash and
main-photo relation, plus a `group_key` every member of a shot carries. The key
is computed when the timeline is replaced, in three steps — the server relation
first, because it knows about live photos and bursts and we do not have to guess
at them; then same capture day, same file-name stem and one member raw while the
other is not, which is the pair a camera writes; otherwise the photo is its own
group. The member the grid shows is the non-raw one, since a JPEG decodes in
milliseconds and is what the person expects to see.

The gallery therefore pages by group and carries `group_size` and `has_raw` on
each entry, and the date scrubber counts what the page shows. The Raw tab is the
exception and still lists every raw file, because that tab exists to answer
"which raws do I have". Album pages are not grouped at all: an album is a list
someone made, and it shows exactly what they put in it.

`TimelineRow` is a struct now. It had grown to five positional fields and was
about to grow to seven, at which point nobody can read a call site.

crates/pdfs-core/src/db/tests.rs

@@ -113,9 +113,13 @@ fn node_from(parent: serde_json::Value, link: &str, name: &str, kind: serde_json
 fn photos_replace_keeps_what_was_learned_and_drops_what_left() {
     let db = Db::open_in_memory().unwrap();
     db.photos_replace(&[
-        ("p1".into(), 300, None, Some("video/mp4".into()), Some(true)),
-        ("p2".into(), 200, None, None, None),
-        ("p3".into(), 100, None, None, None),
+        TimelineRow {
+            media_type: Some("video/mp4".into()),
+            favorite: Some(true),
+            ..TimelineRow::new("p1", 300)
+        },
+        TimelineRow::new("p2", 200),
+        TimelineRow::new("p3", 100),
     ])
     .unwrap();
 
@@ -126,9 +130,13 @@ fn photos_replace_keeps_what_was_learned_and_drops_what_left() {
     // 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(&[
-        ("p0".into(), 400, Some("new.jpg".into()), None, Some(false)),
-        ("p1".into(), 300, None, None, None),
-        ("p2".into(), 200, None, None, None),
+        TimelineRow {
+            name: Some("new.jpg".into()),
+            favorite: Some(false),
+            ..TimelineRow::new("p0", 400)
+        },
+        TimelineRow::new("p1", 300),
+        TimelineRow::new("p2", 200),
     ])
     .unwrap();
 
@@ -200,8 +208,14 @@ fn photos_replace_keeps_what_was_learned_and_drops_what_left() {
 fn favorites_are_remembered_across_refreshes_and_filter_a_page() {
     let db = Db::open_in_memory().unwrap();
     db.photos_replace(&[
-        ("p1".into(), 300, None, None, Some(true)),
-        ("p2".into(), 200, None, None, Some(false)),
+        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).unwrap();
@@ -215,8 +229,11 @@ fn favorites_are_remembered_across_refreshes_and_filter_a_page() {
     // (`None`), and loses to one that could.
     db.photos_set_favorite("p2", true).unwrap();
     db.photos_replace(&[
-        ("p1".into(), 300, None, None, Some(false)),
-        ("p2".into(), 200, None, None, None),
+        TimelineRow {
+            favorite: Some(false),
+            ..TimelineRow::new("p1", 300)
+        },
+        TimelineRow::new("p2", 200),
     ])
     .unwrap();
     let favorites = db.photos_page(0, 10, None, None, true).unwrap();
@@ -232,7 +249,7 @@ fn favorites_are_remembered_across_refreshes_and_filter_a_page() {
 fn photos_page_slices_the_timeline_in_order() {
     let db = Db::open_in_memory().unwrap();
     let items: Vec<_> = (0..5)
-        .map(|i| (format!("p{i}"), 500 - i as i64, None, None::<String>, None))
+        .map(|i| TimelineRow::new(format!("p{i}"), 500 - i as i64))
         .collect();
     db.photos_replace(&items).unwrap();
 
@@ -3926,9 +3943,9 @@ fn an_idle_worker_does_not_wait_on_an_op_another_worker_has() {
 fn photos_delete_removes_the_photo_and_its_album_membership() {
     let db = Db::open_in_memory().unwrap();
     db.photos_replace(&[
-        ("p1".into(), 300, None, None, None),
-        ("p2".into(), 200, None, None, None),
-        ("p3".into(), 100, None, None, None),
+        TimelineRow::new("p1", 300),
+        TimelineRow::new("p2", 200),
+        TimelineRow::new("p3", 100),
     ])
     .unwrap();
     db.albums_replace(&[StoredAlbum {
@@ -3970,3 +3987,117 @@ fn photos_delete_removes_the_photo_and_its_album_membership() {
     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).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)
+        .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);
+}
+
+/// 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).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).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);
+}