implemented database for search

crates/pdfs-cli/src/main.rs

@@ -2,6 +2,7 @@
 
 use std::io::Write;
 use std::path::{Path, PathBuf};
+use std::sync::Arc;
 
 use anyhow::{Context, Result, anyhow, bail};
 use clap::{Parser, Subcommand};
@@ -9,6 +10,7 @@ use pdfs_core::auth;
 use pdfs_core::cache::ContentCache;
 use pdfs_core::config::AppDirs;
 use pdfs_core::control::{Request as CtlRequest, Response as CtlResponse};
+use pdfs_core::db::Db;
 
 #[derive(Parser)]
 #[command(
@@ -76,6 +78,14 @@ enum Command {
         /// Photo node uid in `volume~link` form (from `pdfs photos`).
         uid: String,
     },
+    /// Search file/folder names via the running daemon's local index.
+    Search {
+        /// Query string (substring match).
+        query: String,
+        /// Max hits to return.
+        #[arg(long, default_value_t = 50)]
+        limit: usize,
+    },
 }
 
 fn main() -> Result<()> {
@@ -102,6 +112,7 @@ fn main() -> Result<()> {
         Command::Ls { path } => cmd_ls(path),
         Command::Photos { limit, offset } => cmd_photos(limit, offset),
         Command::OpenPhoto { uid } => cmd_open_photo(uid),
+        Command::Search { query, limit } => cmd_search(query, limit),
     }
 }
 
@@ -217,10 +228,15 @@ fn mount_once(mountpoint: Option<PathBuf>) -> Result<pdfs_fuse::MountOutcome> {
         .with_context(|| format!("create mountpoint {}", mountpoint.display()))?;
 
     let username = auth::load().map(|s| s.username).unwrap_or_default();
+    // The daemon owns the unified DB (single writer). Open it here so the content
+    // cache and the mount share one handle: the cache uses its `cache_entries`
+    // table as the LRU index, the mount uses it for nodes/search/event cursor.
+    let db = Arc::new(Db::open(&dirs.db_path()).context("open cache db")?);
     let cache = ContentCache::open(
         dirs.content_cache_dir(),
         dirs.pins_path(),
         pdfs_core::config::DEFAULT_CACHE_BUDGET_BYTES,
+        db.clone(),
     )
     .context("open content cache")?;
     let control_socket = dirs.control_socket();
@@ -272,6 +288,7 @@ fn mount_once(mountpoint: Option<PathBuf>) -> Result<pdfs_fuse::MountOutcome> {
         &mountpoint,
         cache,
         &control_socket,
+        db,
         username,
     );
 
@@ -371,6 +388,22 @@ fn cmd_open_photo(uid: String) -> Result<()> {
     Ok(())
 }
 
+fn cmd_search(query: String, limit: usize) -> Result<()> {
+    match control_request(CtlRequest::Search { query, limit })? {
+        CtlResponse::SearchResults { hits } if hits.is_empty() => println!("(no matches)"),
+        CtlResponse::SearchResults { hits } => {
+            for h in hits {
+                let kind = if h.is_dir { "d" } else { "-" };
+                let pin = if h.pinned { "*" } else { " " };
+                println!("{kind}{pin} {:>12}  {}", h.size, h.path);
+            }
+        }
+        CtlResponse::Error { message } => bail!("{message}"),
+        other => bail!("unexpected response: {other:?}"),
+    }
+    Ok(())
+}
+
 /// Normalize a user-supplied path argument for sending to the daemon. Absolute
 /// paths are canonicalized (so the daemon can strip its mountpoint prefix);
 /// relative paths are passed through and resolved against the mount root.

crates/pdfs-core/Cargo.toml

@@ -17,4 +17,5 @@ thiserror.workspace = true
 tracing.workspace = true
 directories.workspace = true
 sha2.workspace = true
+rusqlite.workspace = true
 keyring.workspace = true

crates/pdfs-core/src/cache.rs

@@ -19,14 +19,32 @@
 use std::collections::{BTreeMap, HashSet};
 use std::io::{Read, Seek, SeekFrom};
 use std::path::{Path, PathBuf};
-use std::time::SystemTime;
+use std::sync::Arc;
+use std::time::{SystemTime, UNIX_EPOCH};
 
 use proton_drive_rs::proton_sdk::ids::NodeUid;
 use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
 
+use crate::db::Db;
 use crate::error::Result;
 
+/// `cache_entries.kind` tag for whole-file content blobs.
+const KIND_BLOB: &str = "blob";
+/// `cache_entries.kind` tag for on-demand block-cache chunks.
+const KIND_BLOCK: &str = "block";
+
+/// Current wall-clock time in unix *milliseconds*, for the LRU `last_accessed`
+/// column. Milliseconds (not seconds) so two cache events in the same second
+/// still order correctly — a coarse second-granularity clock would make LRU
+/// eviction order indeterminate under bursty access.
+fn now_millis() -> i64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|d| d.as_millis() as i64)
+        .unwrap_or(0)
+}
+
 /// Block size for the on-demand block cache. Matches the SDK content block size
 /// (`DEFAULT_BLOCK_SIZE`, 4 MiB) so each cached block maps to exactly one
 /// `download_range` fetch with no straddling.
@@ -42,18 +60,22 @@ struct Meta {
     size: u64,
 }
 
-/// One pinned file, as persisted to the pin registry.
+/// One pin, as carried over the control socket and listed in `status`.
 #[derive(Serialize, Deserialize, Clone, Debug)]
 pub struct Pin {
     /// Node uid in `volume~link` display form.
     pub uid: String,
-    /// Last path the file was pinned under, for display in `status`. Advisory
+    /// Last path the node was pinned under, for display in `status`. Advisory
     /// only — the uid is the identity.
     pub path: String,
+    /// A folder pin whose whole subtree is kept on disk. `false` for a single
+    /// file. Defaulted so a legacy `pins.json` (file pins only) still parses.
+    #[serde(default)]
+    pub recursive: bool,
 }
 
-/// The pin registry, persisted as JSON. Keyed by uid display string so a pin
-/// survives renames/moves of the node.
+/// The legacy JSON pin registry, kept only to import a pre-P5 `pins.json` into
+/// the DB once on open. Live pins are owned by the `pins` table.
 #[derive(Serialize, Deserialize, Default)]
 struct PinFile {
     pins: BTreeMap<String, Pin>,
@@ -80,13 +102,24 @@ pub struct ContentCache {
     /// disables the cap. Pinned blobs are never evicted, so pins alone may push
     /// the cache over budget.
     max_bytes: u64,
+    /// Unified metadata DB. Its `cache_entries` table is the LRU index: every
+    /// store/read/evict updates it, and the budget enforcers query it instead of
+    /// scanning the cache directories (plan.md P4).
+    db: Arc<Db>,
 }
 
 impl ContentCache {
     /// Open (and create) a cache under `content_dir`, with the pin registry at
     /// `pins_path` and a `max_bytes` size cap (`0` = unlimited). Both parent
-    /// directories are created if missing.
-    pub fn open(content_dir: PathBuf, pins_path: PathBuf, max_bytes: u64) -> Result<Self> {
+    /// directories are created if missing. `db` is the shared metadata database
+    /// whose `cache_entries` table backs LRU eviction; the on-disk cache is
+    /// reconciled into it on open.
+    pub fn open(
+        content_dir: PathBuf,
+        pins_path: PathBuf,
+        max_bytes: u64,
+        db: Arc<Db>,
+    ) -> Result<Self> {
         std::fs::create_dir_all(&content_dir)?;
         let thumb_dir = content_dir.join("thumbs");
         std::fs::create_dir_all(&thumb_dir)?;
@@ -100,14 +133,71 @@ impl ContentCache {
         if let Some(parent) = pins_path.parent() {
             std::fs::create_dir_all(parent)?;
         }
-        Ok(Self {
+        let cache = Self {
             content_dir,
             thumb_dir,
             block_dir,
             scratch_dir,
             pins_path,
             max_bytes,
-        })
+            db,
+        };
+        cache.reconcile()?;
+        cache.import_legacy_pins()?;
+        Ok(cache)
+    }
+
+    /// One-time migration of a pre-P5 `pins.json` into the DB `pins` table, then
+    /// delete the file so it never re-imports. Legacy pins were all whole-file
+    /// (non-recursive). Absent file → nothing to do.
+    fn import_legacy_pins(&self) -> Result<()> {
+        let Ok(bytes) = std::fs::read(&self.pins_path) else {
+            return Ok(());
+        };
+        if let Ok(file) = serde_json::from_slice::<PinFile>(&bytes) {
+            for (uid, pin) in file.pins {
+                self.db.pin_add(&uid, &pin.path, false)?;
+            }
+        }
+        let _ = std::fs::remove_file(&self.pins_path);
+        Ok(())
+    }
+
+    /// Rebuild the `cache_entries` LRU index from the on-disk cache. Called once
+    /// on open: the index is cleared, then every blob (`content_dir`) and block
+    /// (`block_dir`) file is re-registered with its on-disk size and last-modified
+    /// time as the initial LRU key. This makes the DB authoritative even after a
+    /// crash or an external file deletion, and picks up caches written by builds
+    /// predating the index. In-run accesses then refine the ordering.
+    fn reconcile(&self) -> Result<()> {
+        self.db.cache_clear()?;
+        for (dir, kind) in [
+            (&self.content_dir, KIND_BLOB),
+            (&self.block_dir, KIND_BLOCK),
+        ] {
+            let Ok(rd) = std::fs::read_dir(dir) else {
+                continue;
+            };
+            for entry in rd.flatten() {
+                let name = entry.file_name();
+                let Some(name) = name.to_str() else { continue };
+                if name.ends_with(".meta") || name.ends_with(".tmp") {
+                    continue;
+                }
+                let Ok(meta) = entry.metadata() else { continue };
+                if !meta.is_file() {
+                    continue;
+                }
+                let at = meta
+                    .modified()
+                    .ok()
+                    .and_then(|t| t.duration_since(UNIX_EPOCH).ok())
+                    .map(|d| d.as_millis() as i64)
+                    .unwrap_or(0);
+                self.db.cache_touch(name, kind, meta.len(), at)?;
+            }
+        }
+        Ok(())
     }
 
     /// Filesystem-safe, fixed-length cache key for a uid display string: the
@@ -171,10 +261,10 @@ impl ContentCache {
         len: u64,
     ) -> Option<Vec<u8>> {
         let blob = self.valid_blob(uid, mtime, size)?;
-        // Record the access for LRU: bump the blob's mtime to now. Best effort —
-        // a failed touch only makes eviction order slightly less accurate.
+        // Record the access for LRU in the cache index. Best effort — a failed
+        // update only makes eviction order slightly less accurate.
+        let _ = self.db.cache_accessed(&Self::key(uid), now_millis());
         let mut f = std::fs::File::open(&blob).ok()?;
-        let _ = f.set_times(std::fs::FileTimes::new().set_modified(SystemTime::now()));
         if offset >= size {
             return Some(Vec::new());
         }
@@ -197,12 +287,22 @@ impl ContentCache {
         std::fs::rename(&tmp, &blob)?;
         let meta = serde_json::to_vec(&Meta { mtime, size })?;
         std::fs::write(self.meta_path(uid), meta)?;
+        // Register the blob in the LRU index before enforcing the budget so the
+        // newest entry is weighed (and ordered most-recent) like any other.
+        self.db
+            .cache_touch(&Self::key(uid), KIND_BLOB, bytes.len() as u64, now_millis())?;
         self.enforce_budget();
         Ok(())
     }
 
+    /// Cache-index key for block `idx` of `uid` — the block file's name, which
+    /// is also its `cache_entries.cache_key`.
+    fn block_key(&self, uid: &NodeUid, idx: u64) -> String {
+        format!("{}.b{idx}", Self::key(uid))
+    }
+
     fn block_blob(&self, uid: &NodeUid, idx: u64) -> PathBuf {
-        self.block_dir.join(format!("{}.b{idx}", Self::key(uid)))
+        self.block_dir.join(self.block_key(uid, idx))
     }
 
     fn block_meta(&self, uid: &NodeUid, idx: u64) -> PathBuf {
@@ -222,7 +322,10 @@ impl ContentCache {
             return None;
         }
         let mut f = std::fs::File::open(self.block_blob(uid, idx)).ok()?;
-        let _ = f.set_times(std::fs::FileTimes::new().set_modified(SystemTime::now()));
+        // LRU touch in the cache index (best effort).
+        let _ = self
+            .db
+            .cache_accessed(&self.block_key(uid, idx), now_millis());
         let mut buf = Vec::new();
         f.read_to_end(&mut buf).ok()?;
         Some(buf)
@@ -249,6 +352,12 @@ impl ContentCache {
             self.block_meta(uid, idx),
             serde_json::to_vec(&Meta { mtime, size })?,
         )?;
+        self.db.cache_touch(
+            &self.block_key(uid, idx),
+            KIND_BLOCK,
+            bytes.len() as u64,
+            now_millis(),
+        )?;
         self.enforce_block_budget();
         Ok(())
     }
@@ -260,42 +369,25 @@ impl ContentCache {
         if self.max_bytes == 0 {
             return;
         }
-        let mut total: u64 = 0;
-        let mut blobs: Vec<(PathBuf, u64, SystemTime)> = Vec::new();
-        let Ok(rd) = std::fs::read_dir(&self.block_dir) else {
+        // LRU-ordered (oldest first) block entries straight from the index — no
+        // directory scan. All blocks are evictable; pinned files are served from
+        // whole-file blobs, never blocks.
+        let Ok(entries) = self.db.cache_entries_by_kind(KIND_BLOCK) else {
             return;
         };
-        for entry in rd.flatten() {
-            let path = entry.path();
-            let Some(name) = path.file_name().and_then(|n| n.to_str()) else {
-                continue;
-            };
-            if name.ends_with(".meta") || name.ends_with(".tmp") {
-                continue;
-            }
-            let Ok(meta) = entry.metadata() else { continue };
-            if !meta.is_file() {
-                continue;
-            }
-            total += meta.len();
-            let atime = meta.modified().unwrap_or(SystemTime::UNIX_EPOCH);
-            blobs.push((path, meta.len(), atime));
-        }
+        let mut total: u64 = entries.iter().map(|(_, size)| *size).sum();
         if total <= self.max_bytes {
             return;
         }
-        blobs.sort_by_key(|(_, _, atime)| *atime);
-        for (path, len, _) in blobs {
+        for (key, size) in entries {
             if total <= self.max_bytes {
                 break;
             }
-            let meta = path.with_file_name(format!(
-                "{}.meta",
-                path.file_name().unwrap_or_default().to_string_lossy()
-            ));
-            let _ = std::fs::remove_file(&path);
-            let _ = std::fs::remove_file(meta);
-            total = total.saturating_sub(len);
+            // `key` is the block file's name (and its `.meta` sibling's stem).
+            let _ = std::fs::remove_file(self.block_dir.join(&key));
+            let _ = std::fs::remove_file(self.block_dir.join(format!("{key}.meta")));
+            let _ = self.db.cache_remove(&key);
+            total = total.saturating_sub(size);
         }
     }
 
@@ -328,7 +420,10 @@ impl ContentCache {
             let _ = std::fs::remove_file(self.thumb_blob(uid, ttype));
             let _ = std::fs::remove_file(self.thumb_meta(uid, ttype));
         }
-        // Drop every cached block (and its meta/tmp) for this uid.
+        // Drop every cached block (and its meta/tmp) for this uid. The block
+        // dir is still scanned here because eviction targets one uid's files by
+        // name prefix, not by LRU order; the index rows are removed in one shot
+        // by `cache_remove_all` below.
         let prefix = format!("{}.b", Self::key(uid));
         if let Ok(rd) = std::fs::read_dir(&self.block_dir) {
             for entry in rd.flatten() {
@@ -341,6 +436,8 @@ impl ContentCache {
                 }
             }
         }
+        // Forget the blob and all of this uid's block rows in the LRU index.
+        let _ = self.db.cache_remove_all(&Self::key(uid));
     }
 
     fn thumb_blob(&self, uid: &NodeUid, ttype: i32) -> PathBuf {
@@ -423,101 +520,80 @@ impl ContentCache {
         if self.max_bytes == 0 {
             return;
         }
-        // Pinned blobs (by cache key) are exempt from eviction.
+        // Pinned blobs (by cache key) are exempt from eviction. Resolves direct
+        // pins plus every descendant of a recursively-pinned folder, hashed into
+        // cache keys to match on-disk filenames.
         let pinned: HashSet<String> = self
-            .load_pins()
-            .pins
-            .keys()
+            .db
+            .pinned_uids()
+            .unwrap_or_default()
+            .iter()
             .map(|uid| Self::key_str(uid))
             .collect();
 
-        // Scan blobs (the `<key>` files; skip `.meta`/`.tmp` siblings), record
-        // size + last-access (mtime) for each.
-        let mut total: u64 = 0;
-        let mut blobs: Vec<(PathBuf, u64, SystemTime)> = Vec::new();
-        let Ok(rd) = std::fs::read_dir(&self.content_dir) else {
+        // LRU-ordered (oldest first) blob entries from the index — no directory
+        // scan. Pinned blobs still count toward the total (so pins alone can hold
+        // the cache over budget) but are never chosen as victims.
+        let Ok(entries) = self.db.cache_entries_by_kind(KIND_BLOB) else {
             return;
         };
-        for entry in rd.flatten() {
-            let path = entry.path();
-            let Some(name) = path.file_name().and_then(|n| n.to_str()) else {
-                continue;
-            };
-            if name.ends_with(".meta") || name.ends_with(".tmp") {
-                continue;
-            }
-            let Ok(meta) = entry.metadata() else { continue };
-            if !meta.is_file() {
-                continue;
-            }
-            total += meta.len();
-            if pinned.contains(name) {
-                continue; // counts toward total but is never a victim
-            }
-            let atime = meta.modified().unwrap_or(SystemTime::UNIX_EPOCH);
-            blobs.push((path, meta.len(), atime));
-        }
+        let mut total: u64 = entries.iter().map(|(_, size)| *size).sum();
         if total <= self.max_bytes {
             return;
         }
-        // Oldest access first.
-        blobs.sort_by_key(|(_, _, atime)| *atime);
-        for (path, len, _) in blobs {
+        for (key, size) in entries {
             if total <= self.max_bytes {
                 break;
             }
-            let _ = std::fs::remove_file(&path);
-            let _ = std::fs::remove_file(path.with_extension("meta"));
-            total = total.saturating_sub(len);
+            if pinned.contains(&key) {
+                continue; // counts toward total but is never a victim
+            }
+            // `key` is the blob file's name (and its `.meta` sibling's stem).
+            let _ = std::fs::remove_file(self.content_dir.join(&key));
+            let _ = std::fs::remove_file(self.content_dir.join(format!("{key}.meta")));
+            let _ = self.db.cache_remove(&key);
+            total = total.saturating_sub(size);
         }
     }
 
-    fn load_pins(&self) -> PinFile {
-        std::fs::read(&self.pins_path)
-            .ok()
-            .and_then(|b| serde_json::from_slice(&b).ok())
-            .unwrap_or_default()
-    }
-
-    fn save_pins(&self, pins: &PinFile) -> Result<()> {
-        std::fs::write(&self.pins_path, serde_json::to_vec_pretty(pins)?)?;
-        Ok(())
-    }
-
-    /// Whether `uid` is pinned (independent of whether its blob is currently
-    /// cached).
+    /// Whether `uid` is pinned — directly, or because an ancestor folder is
+    /// pinned recursively (resolved in the DB against the node tree). Independent
+    /// of whether its blob is currently cached. Best effort: a DB error reads as
+    /// "not pinned" rather than failing the calling FUSE op.
     pub fn is_pinned(&self, uid: &NodeUid) -> bool {
-        self.load_pins().pins.contains_key(&uid.to_string())
+        self.db.is_pinned(&uid.to_string()).unwrap_or(false)
     }
 
-    /// Record `uid` as pinned under `path`. The caller is responsible for having
-    /// already cached the content via [`store`](Self::store).
-    pub fn add_pin(&self, uid: &NodeUid, path: &Path) -> Result<()> {
-        let mut file = self.load_pins();
-        let key = uid.to_string();
-        file.pins.insert(
-            key.clone(),
-            Pin {
-                uid: key,
-                path: path.display().to_string(),
-            },
-        );
-        self.save_pins(&file)
+    /// Record `uid` as pinned under `path`. `recursive` marks a folder pin whose
+    /// whole subtree is kept. The caller is responsible for having cached the
+    /// content (a file via [`store`](Self::store); a folder's descendants by the
+    /// daemon walking the subtree).
+    pub fn add_pin(&self, uid: &NodeUid, path: &Path, recursive: bool) -> Result<()> {
+        self.db
+            .pin_add(&uid.to_string(), &path.display().to_string(), recursive)
     }
 
     /// Drop `uid` from the pin registry and evict its blob. No-op if not pinned.
+    /// A recursively-pinned folder's descendants are evicted by the daemon
+    /// (`Core::unpin`), which knows the node tree.
     pub fn remove_pin(&self, uid: &NodeUid) -> Result<()> {
-        let mut file = self.load_pins();
-        if file.pins.remove(&uid.to_string()).is_some() {
-            self.save_pins(&file)?;
-        }
+        self.db.pin_remove(&uid.to_string())?;
         self.evict(uid);
         Ok(())
     }
 
-    /// All pinned files, ordered by uid.
+    /// All pins (files and recursive folders), ordered by uid.
     pub fn list_pins(&self) -> Vec<Pin> {
-        self.load_pins().pins.into_values().collect()
+        self.db
+            .pin_list()
+            .unwrap_or_default()
+            .into_iter()
+            .map(|(uid, path, recursive)| Pin {
+                uid,
+                path,
+                recursive,
+            })
+            .collect()
     }
 
     /// Total bytes of cached content blobs (pinned + unpinned), matching what
@@ -591,10 +667,12 @@ mod tests {
 
     fn cache_capped(max_bytes: u64) -> (ContentCache, TempDir) {
         let dir = TempDir::new();
+        let db = Arc::new(Db::open_in_memory().unwrap());
         let c = ContentCache::open(
             dir.path().join("content"),
             dir.path().join("pins.json"),
             max_bytes,
+            db,
         )
         .unwrap();
         (c, dir)
@@ -618,6 +696,40 @@ mod tests {
         );
     }
 
+    #[test]
+    fn reconcile_rebuilds_index_from_disk() {
+        let dir = TempDir::new();
+        let content = dir.path().join("content");
+        let pins = dir.path().join("pins.json");
+
+        // First session: unlimited cap, store three blobs onto disk.
+        let db1 = Arc::new(Db::open_in_memory().unwrap());
+        {
+            let c = ContentCache::open(content.clone(), pins.clone(), 0, db1).unwrap();
+            c.store(&uid("a"), 1, 4, b"aaaa").unwrap();
+            c.store(&uid("b"), 1, 4, b"bbbb").unwrap();
+            c.store(&uid("c"), 1, 4, b"cccc").unwrap();
+        }
+
+        // Second session with a *fresh* index (as if predating P4, or after a
+        // crash) but the same on-disk cache: reconcile repopulates from disk.
+        let db2 = Arc::new(Db::open_in_memory().unwrap());
+        assert!(db2.cache_entries_by_kind("blob").unwrap().is_empty());
+        let c = ContentCache::open(content, pins, 8, db2.clone()).unwrap();
+        assert_eq!(db2.cache_entries_by_kind("blob").unwrap().len(), 3);
+
+        // With the index rebuilt, a further store enforces the budget against the
+        // reconciled entries instead of leaking them.
+        c.store(&uid("d"), 1, 4, b"dddd").unwrap();
+        let total: u64 = db2
+            .cache_entries_by_kind("blob")
+            .unwrap()
+            .iter()
+            .map(|(_, s)| s)
+            .sum();
+        assert!(total <= 8, "budget enforced after reconcile, total={total}");
+    }
+
     #[test]
     fn stale_metadata_is_a_miss() {
         let (c, _d) = cache();
@@ -630,12 +742,36 @@ mod tests {
         assert!(c.read_range(&u, 100, 4, 0, 3).is_none());
     }
 
+    #[test]
+    fn legacy_pins_json_imported_then_removed() {
+        let dir = TempDir::new();
+        let pins = dir.path().join("pins.json");
+        // Hand-write a pre-P5 pins.json (file pins only, no `recursive` field).
+        std::fs::write(
+            &pins,
+            r#"{"pins":{"vol~a":{"uid":"vol~a","path":"docs/a.txt"}}}"#,
+        )
+        .unwrap();
+
+        let db = Arc::new(Db::open_in_memory().unwrap());
+        let c = ContentCache::open(dir.path().join("content"), pins.clone(), 0, db).unwrap();
+
+        // Imported into the DB as a non-recursive pin...
+        assert!(c.is_pinned(&uid("a")));
+        let listed = c.list_pins();
+        assert_eq!(listed.len(), 1);
+        assert_eq!(listed[0].path, "docs/a.txt");
+        assert!(!listed[0].recursive);
+        // ...and the legacy file is gone so it never re-imports.
+        assert!(!pins.exists());
+    }
+
     #[test]
     fn pin_lifecycle_evicts_on_unpin() {
         let (c, _d) = cache();
         let u = uid("a");
         c.store(&u, 100, 3, b"abc").unwrap();
-        c.add_pin(&u, Path::new("docs/a.txt")).unwrap();
+        c.add_pin(&u, Path::new("docs/a.txt"), false).unwrap();
         assert!(c.is_pinned(&u));
         assert_eq!(c.list_pins().len(), 1);
         assert_eq!(c.list_pins()[0].path, "docs/a.txt");
@@ -675,7 +811,7 @@ mod tests {
         let (a, b, d) = (uid("a"), uid("b"), uid("d"));
 
         c.store(&a, 1, 4, b"aaaa").unwrap();
-        c.add_pin(&a, Path::new("a")).unwrap();
+        c.add_pin(&a, Path::new("a"), false).unwrap();
         std::thread::sleep(std::time::Duration::from_millis(10));
         c.store(&b, 1, 4, b"bbbb").unwrap();
         // Over budget: `a` is pinned (oldest) so `b` must be the victim.

crates/pdfs-core/src/config.rs

@@ -94,6 +94,12 @@ impl AppDirs {
         self.state_dir().join("pins.json")
     }
 
+    /// Unified SQLite metadata cache (inodes, FTS, cache LRU, pins). Lives in
+    /// persistent state next to `control.sock`; only the daemon writes it.
+    pub fn db_path(&self) -> PathBuf {
+        self.state_dir().join("cache.db")
+    }
+
     /// Unix domain socket the mount daemon listens on for CLI control commands.
     pub fn control_socket(&self) -> PathBuf {
         self.state_dir().join("control.sock")

crates/pdfs-core/src/control.rs

@@ -49,10 +49,20 @@ pub enum Request {
     PhotosTimeline { offset: usize, limit: usize },
     /// Download a photo's full content into the cache; replies with its path.
     OpenPhoto { uid: String },
+    /// Upload a photo with the given name, media type, and content bytes.
+    UploadPhoto {
+        name: String,
+        media_type: String,
+        bytes: Vec<u8>,
+        capture_time: Option<i64>,
+    },
     /// Download a Drive file's full content into the cache; replies with the
     /// on-disk path so the front-end can open it with the default app. `path`
     /// is mountpoint-relative.
     OpenFile { path: String },
+    /// Full-text search node names against the daemon's local metadata index.
+    /// `limit` caps the number of hits returned. Replies with [`Response::SearchResults`].
+    Search { query: String, limit: usize },
 }
 
 /// One entry in a [`Request::ListDir`] listing.
@@ -69,6 +79,28 @@ pub struct DirEntry {
     pub pinned: bool,
     /// Node uid in `volume~link` form, for follow-up requests.
     pub uid: String,
+    /// Full mountpoint-relative path. Empty for a [`Request::ListDir`] listing
+    /// (the entry lives in the requested directory, so the caller derives the
+    /// path by joining its name); populated when an entry can live anywhere in
+    /// the tree, as for search hits rendered through the browser.
+    #[serde(default)]
+    pub path: String,
+}
+
+/// One hit in a [`Request::Search`] result. Like [`DirEntry`] but carries the
+/// full mountpoint-relative `path` (a hit can live anywhere in the tree), so the
+/// front-end can navigate to or open it directly.
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct SearchHit {
+    pub name: String,
+    /// Mountpoint-relative path (`/`-joined, no leading slash).
+    pub path: String,
+    pub is_dir: bool,
+    pub size: u64,
+    pub modified: i64,
+    pub pinned: bool,
+    /// Node uid in `volume~link` form.
+    pub uid: String,
 }
 
 /// One photo in a [`Request::PhotosTimeline`] page.
@@ -113,6 +145,8 @@ pub enum Response {
     },
     /// An on-disk path the front-end can open (e.g. a downloaded photo).
     FilePath { path: String },
+    /// Full-text search results (reply to [`Request::Search`]).
+    SearchResults { hits: Vec<SearchHit> },
     /// The request failed.
     Error { message: String },
 }

crates/pdfs-core/src/error.rs

@@ -16,6 +16,9 @@ pub enum Error {
     #[error("io: {0}")]
     Io(#[from] std::io::Error),
 
+    #[error("database: {0}")]
+    Db(#[from] rusqlite::Error),
+
     /// No persisted session found — caller must run an interactive login.
     #[error("not logged in (no saved session)")]
     NotLoggedIn,

crates/pdfs-core/src/lib.rs

@@ -6,6 +6,7 @@ pub mod auth;
 pub mod cache;
 pub mod config;
 pub mod control;
+pub mod db;
 pub mod error;
 pub mod service;
 

crates/pdfs-fuse/src/lib.rs

@@ -49,7 +49,10 @@ use fuser::{
     ReplyWrite, Request, Session, TimeOrNow, WriteFlags,
 };
 use pdfs_core::cache::{BLOCK_SIZE, ContentCache};
-use pdfs_core::control::{DirEntry, PhotoItem, Request as CtlRequest, Response as CtlResponse};
+use pdfs_core::control::{
+    DirEntry, PhotoItem, Request as CtlRequest, Response as CtlResponse, SearchHit,
+};
+use pdfs_core::db::{Db, StoredNode};
 use proton_drive_rs::proton_sdk::ids::{DriveEventId, LinkId, NodeUid, VolumeId};
 use proton_drive_rs::{
     DriveEvent, DriveEventScopeId, Node, NodeKind, PhotosTimelineItem, ProtonDriveClient,
@@ -186,11 +189,19 @@ struct State {
     /// have no entry here.
     handles: HashMap<u64, WriteHandle>,
     next_fh: u64,
+    /// Unified SQLite metadata cache. Every map mutation below writes through to
+    /// it inside the `State` lock so the DB stays the authoritative copy across
+    /// restarts (see plan.md P1).
+    db: Arc<Db>,
 }
 
 impl State {
-    /// Allocate (or reuse) a stable inode for a node and store its metadata.
+    /// Allocate (or reuse) a stable inode for a node and store its metadata,
+    /// writing the node through to the DB.
     fn intern(&mut self, parent: u64, node: Node) -> u64 {
+        if let Err(e) = self.db.upsert_node(&node) {
+            warn!(uid = %node.uid, error = %e, "db upsert_node failed");
+        }
         if let Some(&ino) = self.by_uid.get(&node.uid) {
             if let Some(e) = self.entries.get_mut(&ino) {
                 e.node = node;
@@ -213,10 +224,14 @@ impl State {
     }
 
     /// Forget a node entirely: drop its inode, its uid mapping, its own cached
-    /// listing, and its slot in its parent's listing. Returns `(parent_ino,
-    /// name)` when the node was known, so the caller can notify the kernel.
+    /// listing, its slot in its parent's listing, and its DB row. Returns
+    /// `(parent_ino, name)` when the node was known, so the caller can notify
+    /// the kernel.
     fn forget(&mut self, uid: &NodeUid) -> Option<(u64, String)> {
         let ino = self.by_uid.remove(uid)?;
+        if let Err(e) = self.db.delete_node(uid) {
+            warn!(%uid, error = %e, "db delete_node failed");
+        }
         let entry = self.entries.remove(&ino)?;
         self.children.remove(&ino);
         if let Some(kids) = self.children.get_mut(&entry.parent) {
@@ -225,6 +240,20 @@ impl State {
         Some((entry.parent, entry.node.name))
     }
 
+    /// Drop a directory's cached child listing and mark it unlisted in the DB,
+    /// so the next access re-enumerates instead of trusting a stale listing.
+    fn invalidate_listing(&mut self, ino: u64) {
+        if self.children.remove(&ino).is_none() {
+            return;
+        }
+        if let Some(e) = self.entries.get(&ino) {
+            let uid = e.uid.clone();
+            if let Err(err) = self.db.set_listed(&uid, false) {
+                warn!(%uid, error = %err, "db set_listed(false) failed");
+            }
+        }
+    }
+
     /// Update a file entry's recorded plaintext size so `getattr` reflects an
     /// in-progress write before the new revision is sealed.
     fn set_size(&mut self, ino: u64, size: u64) {
@@ -255,6 +284,10 @@ struct Core {
     rt: tokio::runtime::Handle,
     state: Arc<Mutex<State>>,
     cache: Arc<ContentCache>,
+    /// Unified SQLite metadata cache: the persistence layer behind the in-memory
+    /// `State` maps. Every mutation writes through here, and the maps rehydrate
+    /// from it on mount (plan.md P1).
+    db: Arc<Db>,
     /// Cached full photos timeline (newest first), so paged `PhotosTimeline`
     /// requests slice memory instead of re-fetching the whole timeline per page.
     /// `None` until first fetched; refreshed once older than [`TIMELINE_TTL`].
@@ -268,6 +301,71 @@ struct TimelineCache {
 }
 
 impl Core {
+    /// Rehydrate the in-memory `State` maps from the DB on mount, so a cold
+    /// start serves previously-seen metadata (stable inodes, instant listings)
+    /// without re-hitting the API. The root inode is already installed by
+    /// [`ProtonFs::new`]; this fills in every other persisted node and rebuilds
+    /// the child listings of folders the DB records as fully enumerated.
+    fn hydrate(&self) {
+        let stored = match self.db.load_all() {
+            Ok(s) => s,
+            Err(e) => {
+                warn!(error = %e, "db load_all failed; mounting cold");
+                return;
+            }
+        };
+        if stored.is_empty() {
+            return;
+        }
+        let mut st = self.state.lock().unwrap();
+
+        // Pass 1: assign a stable inode to every uid (root is already mapped).
+        for sn in &stored {
+            if st.by_uid.contains_key(&sn.node.uid) {
+                continue;
+            }
+            let ino = st.next_ino;
+            st.next_ino += 1;
+            st.by_uid.insert(sn.node.uid.clone(), ino);
+        }
+
+        // Pass 2: materialize entries, resolving each parent's inode by uid.
+        // Track folders flagged complete so their listings rebuild in pass 3.
+        let mut listed_dirs: Vec<u64> = Vec::new();
+        for sn in stored {
+            let StoredNode { node, listed } = sn;
+            let Some(&ino) = st.by_uid.get(&node.uid) else {
+                continue;
+            };
+            if listed && node.is_folder() {
+                listed_dirs.push(ino);
+            }
+            // The root entry is owned by `ProtonFs::new`; don't overwrite it.
+            if ino == ROOT_INO {
+                continue;
+            }
+            let parent = node
+                .parent_uid
+                .as_ref()
+                .and_then(|p| st.by_uid.get(p).copied())
+                .unwrap_or(ROOT_INO);
+            let uid = node.uid.clone();
+            st.entries.insert(ino, Entry { uid, parent, node });
+        }
+
+        // Pass 3: rebuild child listings for fully-enumerated folders.
+        for dir_ino in listed_dirs {
+            let kids: Vec<u64> = st
+                .entries
+                .iter()
+                .filter(|(_, e)| e.parent == dir_ino && !e.node.trashed)
+                .map(|(&ino, _)| ino)
+                .collect();
+            st.children.insert(dir_ino, kids);
+        }
+        info!(nodes = st.entries.len(), "hydrated metadata cache from db");
+    }
+
     /// Enumerate `ino`'s children from the remote and cache them. No-op if the
     /// directory has already been listed. Network I/O happens without the lock
     /// held so concurrent metadata reads aren't blocked behind a fetch.
@@ -283,6 +381,29 @@ impl Core {
             }
         };
 
+        // Offline fast path: a folder the DB still records as fully enumerated
+        // can be rebuilt from disk without hitting the API, even if its listing
+        // was trimmed from the hot cache mid-run.
+        match self.db.children_if_listed(&folder_uid) {
+            Ok(Some(nodes)) => {
+                let mut st = self.state.lock().unwrap();
+                if st.children.contains_key(&ino) {
+                    return Ok(());
+                }
+                let mut child_inos = Vec::with_capacity(nodes.len());
+                for node in nodes {
+                    if node.trashed {
+                        continue;
+                    }
+                    child_inos.push(st.intern(ino, node));
+                }
+                st.children.insert(ino, child_inos);
+                return Ok(());
+            }
+            Ok(None) => {}
+            Err(e) => warn!(%folder_uid, error = %e, "db children_if_listed failed"),
+        }
+
         let uids = self
             .rt
             .block_on(self.client.enumerate_folder_children_node_uids(&folder_uid))
@@ -311,6 +432,11 @@ impl Core {
             child_inos.push(st.intern(ino, node));
         }
         st.children.insert(ino, child_inos);
+        // Record the listing as complete so a later restart (or a trimmed hot
+        // cache) can rebuild it from the DB without the API.
+        if let Err(e) = self.db.set_listed(&folder_uid, true) {
+            warn!(%folder_uid, error = %e, "db set_listed(true) failed");
+        }
         Ok(())
     }
 
@@ -553,25 +679,32 @@ impl Core {
         Ok(())
     }
 
-    /// Pin the file at mountpoint-relative `rel`: download its full plaintext
-    /// into the content cache and record it in the pin registry. Returns the
-    /// resolved node name on success.
+    /// Pin the node at mountpoint-relative `rel`. A file downloads its full
+    /// plaintext into the content cache; a folder records a recursive pin and
+    /// downloads every descendant file (selective sync). Returns a human message.
     fn pin(&self, rel: &Path) -> Result<String, String> {
         let (ino, uid) = self
             .resolve_path(rel)
             .map_err(|e| format!("resolve path: {e:?}"))?;
-        let (name, mtime, size) = {
+        let (name, is_folder, mtime, size) = {
             let st = self.state.lock().unwrap();
             let e = st.entries.get(&ino).ok_or("node vanished")?;
-            if !e.node.is_file() {
-                return Err("not a regular file".into());
-            }
             (
                 e.node.name.clone(),
+                e.node.is_folder(),
                 e.node.modification_time,
                 node_size(&e.node),
             )
         };
+        if is_folder {
+            // Record the recursive pin first so every descendant is eviction-
+            // exempt before we start filling the cache with the subtree.
+            self.cache
+                .add_pin(&uid, rel, true)
+                .map_err(|e| format!("pin: {e}"))?;
+            let n = self.pin_subtree(ino)?;
+            return Ok(format!("{name} ({n} files)"));
+        }
         let bytes = self
             .rt
             .block_on(self.client.download_file(&uid))
@@ -580,11 +713,56 @@ impl Core {
             .store(&uid, mtime, size, &bytes)
             .map_err(|e| format!("cache store: {e}"))?;
         self.cache
-            .add_pin(&uid, rel)
+            .add_pin(&uid, rel, false)
             .map_err(|e| format!("pin: {e}"))?;
         Ok(name)
     }
 
+    /// Download and cache every file in the subtree rooted at folder `ino`,
+    /// returning the count cached (already-fresh blobs counted, not re-fetched).
+    /// Walks the tree depth-first, enumerating each folder so a cold subtree is
+    /// fully discovered; the lock is dropped before each network download.
+    fn pin_subtree(&self, ino: u64) -> Result<usize, String> {
+        let mut files: Vec<(NodeUid, i64, u64)> = Vec::new();
+        let mut stack = vec![ino];
+        while let Some(dir) = stack.pop() {
+            self.ensure_children(dir)
+                .map_err(|e| format!("enumerate: {e:?}"))?;
+            let st = self.state.lock().unwrap();
+            if let Some(kids) = st.children.get(&dir) {
+                for &k in kids {
+                    if let Some(e) = st.entries.get(&k) {
+                        if e.node.is_folder() {
+                            stack.push(k);
+                        } else {
+                            files.push((
+                                e.uid.clone(),
+                                e.node.modification_time,
+                                node_size(&e.node),
+                            ));
+                        }
+                    }
+                }
+            }
+        }
+        let mut count = 0;
+        for (uid, mtime, size) in files {
+            if self.cache.is_cached(&uid, mtime, size) {
+                count += 1;
+                continue;
+            }
+            match self.rt.block_on(self.client.download_file(&uid)) {
+                Ok(bytes) => {
+                    if self.cache.store(&uid, mtime, size, &bytes).is_ok() {
+                        count += 1;
+                    }
+                }
+                Err(e) => warn!(%uid, error = %e, "pin subtree: download failed"),
+            }
+        }
+        Ok(count)
+    }
+
     /// Fetch a thumbnail of `ttype` for the file at `ino`, served from the cache
     /// when fresh and otherwise downloaded from the remote and cached. Returns
     /// `Ok(None)` when the node is not a file or has no thumbnail of that type.
@@ -615,21 +793,32 @@ impl Core {
         Ok(bytes)
     }
 
-    /// Unpin the file at `rel`, evicting its cached content.
+    /// Unpin the node at `rel`, evicting its cached content. For a folder, also
+    /// evicts every descendant's cached blob (the subtree is no longer kept).
     fn unpin(&self, rel: &Path) -> Result<String, String> {
         let (ino, uid) = self
             .resolve_path(rel)
             .map_err(|e| format!("resolve path: {e:?}"))?;
-        let name = {
+        let (name, is_folder) = {
             let st = self.state.lock().unwrap();
             st.entries
                 .get(&ino)
-                .map(|e| e.node.name.clone())
+                .map(|e| (e.node.name.clone(), e.node.is_folder()))
                 .unwrap_or_default()
         };
         self.cache
             .remove_pin(&uid)
             .map_err(|e| format!("unpin: {e}"))?;
+        // A recursively-pinned folder's descendants were eviction-exempt; now
+        // that the pin is gone, reclaim their blobs eagerly instead of waiting
+        // for budget pressure. Descendants come from the DB node tree.
+        if is_folder && let Ok(uids) = self.db.descendants(&uid.to_string()) {
+            for s in uids {
+                if let Some(u) = parse_uid(&s) {
+                    self.cache.evict(&u);
+                }
+            }
+        }
         Ok(name)
     }
 
@@ -681,6 +870,31 @@ impl Core {
                 modified,
                 pinned: self.cache.is_pinned(&uid),
                 uid: uid.to_string(),
+                // Listing entries live in the requested dir; the caller derives
+                // the path from its name. Left empty.
+                path: String::new(),
+            })
+            .collect())
+    }
+
+    /// Full-text search node names against the local SQLite index, mapping each
+    /// DB hit to the wire [`SearchHit`] (resolving live pin state from the cache,
+    /// which the DB doesn't track). Pure local lookup — never hits the network.
+    fn search(&self, query: &str, limit: usize) -> Result<Vec<SearchHit>, String> {
+        let hits = self
+            .db
+            .search(query, limit)
+            .map_err(|e| format!("search: {e}"))?;
+        Ok(hits
+            .into_iter()
+            .map(|h| SearchHit {
+                name: h.node.name.clone(),
+                path: h.path,
+                is_dir: h.node.is_folder(),
+                size: node_size(&h.node),
+                modified: h.node.modification_time,
+                pinned: self.cache.is_pinned(&h.node.uid),
+                uid: h.node.uid.to_string(),
             })
             .collect())
     }
@@ -855,6 +1069,9 @@ impl ProtonFs {
     fn new(core: Core, root: Node) -> Self {
         {
             let mut st = core.state.lock().unwrap();
+            if let Err(e) = st.db.upsert_node(&root) {
+                warn!(uid = %root.uid, error = %e, "db upsert root failed");
+            }
             st.by_uid.insert(root.uid.clone(), ROOT_INO);
             st.entries.insert(
                 ROOT_INO,
@@ -1710,7 +1927,7 @@ fn apply_event(
                 // Known node changed: drop its cached attrs/data (and listing if
                 // it is a directory) so the next access re-fetches. Its content
                 // blob may now be stale, so evict it too.
-                st.children.remove(&ino);
+                st.invalidate_listing(ino);
                 content.evict(node_uid);
                 let _ = notifier.inval_inode(INodeNo(ino), 0, 0);
             }
@@ -1718,8 +1935,8 @@ fn apply_event(
             // drop it so the new child is picked up on the next readdir.
             if let Some(parent_uid) = parent_node_uid
                 && let Some(&parent) = st.by_uid.get(parent_uid)
-                && st.children.remove(&parent).is_some()
             {
+                st.invalidate_listing(parent);
                 let _ = notifier.inval_inode(INodeNo(parent), 0, 0);
             }
         }
@@ -1746,8 +1963,8 @@ fn apply_event(
             warn!("event continuity lost; dropping all cached listings, resyncing lazily");
             let mut st = state.lock().unwrap();
             let dirs: Vec<u64> = st.children.keys().copied().collect();
-            st.children.clear();
-            for ino in dirs {
+            for &ino in &dirs {
+                st.invalidate_listing(ino);
                 let _ = notifier.inval_inode(INodeNo(ino), 0, 0);
             }
         }
@@ -1758,20 +1975,41 @@ fn apply_event(
 }
 
 /// Poll the remote event cursor forever, applying each batch to the shared
-/// state. Seeds the cursor from the current server head so we only react to
-/// changes made after mount. Runs as a Tokio task; returns only on fatal error.
+/// state. Resumes from the cursor persisted in the DB so changes made while
+/// unmounted are applied; only a first-ever mount seeds from the server head.
+/// The cursor is persisted after every batch. Runs as a Tokio task; returns
+/// only on fatal error.
 async fn run_event_sync(
     client: ProtonDriveClient,
     scope: DriveEventScopeId,
     state: Arc<Mutex<State>>,
     content: Arc<ContentCache>,
+    db: Arc<Db>,
     notifier: Notifier,
 ) {
-    // Seed: a `None` cursor yields a single `CursorAdvanced` at the server head.
-    let mut cursor: Option<DriveEventId> = match client.enumerate_events(&scope, None).await {
-        Ok(events) => events.last().map(|e| e.id().clone()),
+    let mut cursor: Option<DriveEventId> = match db.get_event_cursor() {
+        // Resume: pick up exactly where the last run left off.
+        Ok(Some(saved)) => Some(DriveEventId::from(saved)),
+        // First mount: a `None` cursor yields a single `CursorAdvanced` at the
+        // server head; persist it so the next restart resumes instead of
+        // reseeding (which would skip everything that changed offline).
+        Ok(None) => match client.enumerate_events(&scope, None).await {
+            Ok(events) => {
+                let head = events.last().map(|e| e.id().clone());
+                if let Some(c) = &head
+                    && let Err(e) = db.set_event_cursor(c.as_str())
+                {
+                    warn!(error = %e, "persist seed cursor failed");
+                }
+                head
+            }
+            Err(e) => {
+                error!(error = %e, "failed to seed event cursor; live sync disabled");
+                return;
+            }
+        },
         Err(e) => {
-            error!(error = %e, "failed to seed event cursor; live sync disabled");
+            error!(error = %e, "read persisted cursor failed; live sync disabled");
             return;
         }
     };
@@ -1794,6 +2032,11 @@ async fn run_event_sync(
             apply_event(&state, &content, &notifier, event);
         }
         cursor = events.last().map(|e| e.id().clone());
+        if let Some(c) = &cursor
+            && let Err(e) = db.set_event_cursor(c.as_str())
+        {
+            warn!(error = %e, "persist event cursor failed");
+        }
     }
 }
 
@@ -1889,6 +2132,32 @@ fn handle_control_conn(core: &Core, username: &str, mountpoint: &Path, stream: U
                 message: format!("bad uid: {uid}"),
             },
         },
+        Ok(CtlRequest::UploadPhoto {
+            name,
+            media_type,
+            bytes,
+            capture_time,
+        }) => {
+            let photos = core.photos();
+            let metadata = proton_drive_rs::PhotoUploadMetadata {
+                capture_time,
+                ..Default::default()
+            };
+            match core
+                .rt
+                .block_on(photos.upload_photo(&name, &media_type, &bytes, metadata))
+            {
+                Ok(uid) => {
+                    *core.timeline.lock().unwrap() = None;
+                    CtlResponse::Ok {
+                        message: format!("uploaded photo with uid {uid}"),
+                    }
+                }
+                Err(e) => CtlResponse::Error {
+                    message: format!("upload photo failed: {e}"),
+                },
+            }
+        }
         Ok(CtlRequest::OpenFile { path }) => match rel_to_mount(mountpoint, &path) {
             Ok(rel) => match core.open_file(&rel) {
                 Ok(p) => CtlResponse::FilePath {
@@ -1898,6 +2167,10 @@ fn handle_control_conn(core: &Core, username: &str, mountpoint: &Path, stream: U
             },
             Err(e) => CtlResponse::Error { message: e },
         },
+        Ok(CtlRequest::Search { query, limit }) => match core.search(&query, limit) {
+            Ok(hits) => CtlResponse::SearchResults { hits },
+            Err(e) => CtlResponse::Error { message: e },
+        },
         Err(e) => CtlResponse::Error {
             message: format!("bad request: {e}"),
         },
@@ -1981,6 +2254,7 @@ pub fn mount(
     mountpoint: &Path,
     cache: ContentCache,
     control_socket: &Path,
+    db: Arc<Db>,
     username: String,
 ) -> std::io::Result<MountOutcome> {
     let root = rt
@@ -1998,8 +2272,10 @@ pub fn mount(
             next_ino: 2,
             handles: HashMap::new(),
             next_fh: 1,
+            db: db.clone(),
         })),
         cache: Arc::new(cache),
+        db,
         timeline: Arc::new(Mutex::new(None)),
     };
 
@@ -2029,6 +2305,9 @@ pub fn mount(
     }
 
     let fs = ProtonFs::new(core.clone(), root);
+    // Warm the in-memory maps from the DB so a cold start serves previously
+    // seen metadata without re-hitting the API (plan.md P1).
+    core.hydrate();
 
     // Build the session explicitly (not `mount2`) so we can grab a `Notifier`
     // for the event task. `spawn` runs the session loop on its own background
@@ -2036,7 +2315,7 @@ pub fn mount(
     let bg = Session::new(fs, mountpoint, &config)?.spawn()?;
     let notifier = bg.notifier();
     rt.spawn(run_event_sync(
-        client, scope, core.state, core.cache, notifier,
+        client, scope, core.state, core.cache, core.db, notifier,
     ));
 
     // Stop signals (SIGTERM from `systemctl --user stop`, SIGINT from Ctrl-C)

crates/pdfs-gui/src/app.rs

@@ -32,7 +32,7 @@ use gtk4::glib::BoxedAnyObject;
 
 use pdfs_core::auth;
 use pdfs_core::config::AppDirs;
-use pdfs_core::control::{DirEntry, PhotoItem, Request, Response, send};
+use pdfs_core::control::{DirEntry, PhotoItem, Request, Response, SearchHit, send};
 use pdfs_core::service;
 
 /// How many photos to pull per [`Request::PhotosTimeline`] page.
@@ -47,6 +47,11 @@ const REFRESH_INTERVAL: Duration = Duration::from_secs(2);
 /// Backoff between auto-retries of a Files/Photos load while the mount service
 /// is still coming up (see [`load_browser`] / [`load_gallery`]).
 const CONNECT_RETRY_INTERVAL: Duration = Duration::from_secs(2);
+/// Idle pause after the last keystroke before a search query is sent, so typing
+/// doesn't fire a request per character.
+const SEARCH_DEBOUNCE: Duration = Duration::from_millis(250);
+/// Cap on search hits requested from the daemon.
+const SEARCH_LIMIT: usize = 200;
 
 /// One rendered pin row, retained so [`repaint_pins`] can flip the unpin button's
 /// `sensitive` in place (when the pin set is unchanged) instead of rebuilding.
@@ -112,11 +117,17 @@ struct Ui {
     browser_retry: gtk4::Button,
     /// Mountpoint-relative path the browser is showing (empty = root).
     browser_path: RefCell<String>,
+    /// Debounced full-text search box in the browser header.
+    browser_search: gtk4::SearchEntry,
+    /// Pending debounce timer for the search box; replaced on every keystroke so
+    /// only the last pause actually fires a [`Request::Search`].
+    search_source: RefCell<Option<glib::SourceId>>,
     // Photos (gallery) page.
     gallery_model: gio::ListStore,
     gallery_status: gtk4::Label,
     gallery_retry: gtk4::Button,
     gallery_more: gtk4::Button,
+    gallery_upload: gtk4::Button,
 }
 
 impl Ui {
@@ -173,7 +184,17 @@ fn load_proton_theme() {
          .brand-icon {{ color: {PROTON_PURPLE}; }}\n\
          .file-grid {{ padding: 6px; }}\n\
          .file-tile {{ padding: 8px; border-radius: 10px; }}\n\
-         .file-tile:hover {{ background: alpha({PROTON_PURPLE}, 0.10); }}\n"
+         .file-tile:hover {{ background: alpha({PROTON_PURPLE}, 0.10); }}\n\
+         .photo-viewer-window {{ background-color: #000000; }}\n\
+         .viewer-top-bar {{ background: linear-gradient(to bottom, rgba(0, 0, 0, 0.8), rgba(0, 0, 0, 0)); padding: 12px 24px; color: white; }}\n\
+         .viewer-title {{ font-weight: bold; font-size: 1.1rem; text-shadow: 0 1px 3px rgba(0, 0, 0, 0.9); color: white; }}\n\
+         .viewer-action-btn {{ color: white; background-color: rgba(255, 255, 255, 0.15); border-radius: 50%; padding: 8px; margin-left: 4px; }}\n\
+         .viewer-action-btn:hover {{ background-color: rgba(255, 255, 255, 0.3); color: white; }}\n\
+         .viewer-nav-btn {{ background-color: rgba(0, 0, 0, 0.5); color: white; margin: 24px; padding: 16px; border-radius: 50%; }}\n\
+         .viewer-nav-btn:hover {{ background-color: rgba(0, 0, 0, 0.8); color: white; }}\n\
+         .viewer-status {{ color: #ff5555; font-size: 1.1rem; background-color: rgba(0, 0, 0, 0.8); padding: 12px 24px; border-radius: 8px; text-shadow: 0 1px 2px rgba(0,0,0,0.5); }}\n\
+         .card {{ border-radius: 8px; transition: transform 0.2s ease, filter 0.2s ease; margin: 4px; }}\n\
+         .card:hover {{ transform: scale(1.02); filter: brightness(0.9); }}\n"
     );
     let provider = gtk4::CssProvider::new();
     provider.load_from_string(&css);
@@ -252,15 +273,19 @@ fn build_window(app: &adw::Application) {
         browser_status: browser_widgets.3,
         browser_retry: browser_widgets.6,
         browser_path: RefCell::new(String::new()),
+        browser_search: browser_widgets.7,
+        search_source: RefCell::new(None),
         gallery_model: gallery_widgets.0,
         gallery_status: gallery_widgets.1,
         gallery_retry: gallery_widgets.4,
         gallery_more: gallery_widgets.2,
+        gallery_upload: gallery_widgets.5,
     });
 
     wire_login(&ui);
     wire_logout(&ui, &main_widgets.5);
     wire_browser(&ui, &browser_widgets.4, &browser_widgets.5);
+    wire_search(&ui);
     wire_gallery(&ui, &gallery_widgets.3);
     wire_retry(&ui);
 
@@ -831,6 +856,7 @@ fn build_browser_page() -> (
         gtk4::GridView,
         gtk4::ColumnView,
         gtk4::Button,
+        gtk4::SearchEntry,
     ),
 ) {
     let model = gio::ListStore::new::<BoxedAnyObject>();
@@ -866,9 +892,16 @@ fn build_browser_page() -> (
     toggles.append(&grid_toggle);
     toggles.append(&list_toggle);
 
+    let search = gtk4::SearchEntry::builder()
+        .placeholder_text("Search Drive")
+        .valign(gtk4::Align::Center)
+        .build();
+    search.set_width_chars(18);
+
     let header = gtk4::Box::new(gtk4::Orientation::Horizontal, 8);
     header.append(&back);
     header.append(&crumb);
+    header.append(&search);
     header.append(&toggles);
 
     let status = gtk4::Label::builder().wrap(true).build();
@@ -938,7 +971,7 @@ fn build_browser_page() -> (
 
     (
         inner.upcast(),
-        (model, back, crumb, status, grid, column_view, retry),
+        (model, back, crumb, status, grid, column_view, retry, search),
     )
 }
 
@@ -1165,6 +1198,11 @@ fn entry_at(model: Option<&impl IsA<gio::ListModel>>, pos: u32) -> Option<DirEnt
 fn activate_entry(ui: &Rc<Ui>, entry: &DirEntry) {
     let rel = entry_rel(ui, entry);
     if entry.is_dir {
+        // Descending into a search hit: clear the query so the folder listing
+        // isn't immediately re-masked by a stale search.
+        if !entry.path.is_empty() {
+            ui.browser_search.set_text("");
+        }
         *ui.browser_path.borrow_mut() = rel;
         load_browser(ui);
     } else {
@@ -1217,6 +1255,11 @@ fn toggle_pin(ui: &Rc<Ui>, entry: &DirEntry) {
 /// Join the entry name onto the current browser directory to get its
 /// mountpoint-relative path.
 fn entry_rel(ui: &Rc<Ui>, entry: &DirEntry) -> String {
+    // Search hits carry an absolute (mountpoint-relative) path since they can
+    // live anywhere; plain listing entries derive it from the current folder.
+    if !entry.path.is_empty() {
+        return entry.path.clone();
+    }
     let base = ui.browser_path.borrow();
     if base.is_empty() {
         entry.name.clone()
@@ -1357,6 +1400,97 @@ fn repaint_browser(ui: &Rc<Ui>, entries: &[DirEntry]) {
     }
 }
 
+/// Wire the browser header's search box: debounce keystrokes, then either run a
+/// search or — when cleared — restore the current directory listing.
+fn wire_search(ui: &Rc<Ui>) {
+    let ui_s = ui.clone();
+    ui.browser_search.connect_search_changed(move |_| {
+        // Replace any pending debounce so only the last keystroke's pause fires.
+        if let Some(src) = ui_s.search_source.borrow_mut().take() {
+            src.remove();
+        }
+        let ui_t = ui_s.clone();
+        let src = glib::timeout_add_local_once(SEARCH_DEBOUNCE, move || {
+            ui_t.search_source.borrow_mut().take();
+            let query = ui_t.browser_search.text().trim().to_string();
+            if query.is_empty() {
+                load_browser(&ui_t);
+            } else {
+                run_search(&ui_t, &query);
+            }
+        });
+        *ui_s.search_source.borrow_mut() = Some(src);
+    });
+}
+
+/// Send a [`Request::Search`] to the daemon and render the hits in the browser
+/// views, reusing the same row model so click-to-open and pin work unchanged
+/// (each hit carries its full path; see [`entry_rel`]).
+fn run_search(ui: &Rc<Ui>, query: &str) {
+    ui.browser_model.remove_all();
+    ui.browser_retry.set_visible(false);
+    ui.browser_status.set_label("Searching…");
+    ui.browser_status.set_visible(true);
+
+    ui.busy_begin();
+    let rx = spawn_request(
+        ui.dirs.control_socket(),
+        Request::Search {
+            query: query.to_string(),
+            limit: SEARCH_LIMIT,
+        },
+    );
+    let ui = ui.clone();
+    glib::spawn_future_local(async move {
+        let result = rx.recv().await;
+        ui.busy_end();
+        // The box may have been cleared (or changed) while the reply was in
+        // flight; if so a fresh load/search already owns the model — drop this.
+        if ui.browser_search.text().trim().is_empty() {
+            return;
+        }
+        match result {
+            Ok(Ok(Response::SearchResults { hits })) => repaint_search(&ui, &hits),
+            Ok(Ok(Response::Error { message })) => browser_message(&ui, &message),
+            Ok(Ok(_)) => browser_message(&ui, "Unexpected reply from daemon."),
+            Ok(Err(_)) | Err(_) => browser_unreachable(&ui),
+        }
+    });
+}
+
+/// Repopulate the model with search hits — folders first, then by name — mapping
+/// each [`SearchHit`] to a path-carrying [`DirEntry`] the existing renderers and
+/// handlers already understand.
+fn repaint_search(ui: &Rc<Ui>, hits: &[SearchHit]) {
+    ui.browser_model.remove_all();
+    if hits.is_empty() {
+        browser_message(ui, "No matches.");
+        return;
+    }
+    ui.browser_status.set_visible(false);
+
+    let mut entries: Vec<DirEntry> = hits
+        .iter()
+        .map(|h| DirEntry {
+            name: h.name.clone(),
+            is_dir: h.is_dir,
+            size: h.size,
+            modified: h.modified,
+            pinned: h.pinned,
+            uid: h.uid.clone(),
+            path: h.path.clone(),
+        })
+        .collect();
+    entries.sort_by(|a, b| {
+        b.is_dir
+            .cmp(&a.is_dir)
+            .then_with(|| a.name.to_lowercase().cmp(&b.name.to_lowercase()))
+    });
+    for entry in entries {
+        ui.browser_model.append(&BoxedAnyObject::new(entry));
+    }
+}
+
 /// The Photos page: a [`gtk4::GridView`] of thumbnails backed by a
 /// [`gio::ListStore`] of [`BoxedAnyObject`]-wrapped [`PhotoItem`]s, plus a
 /// "Load more" button and a status label.
@@ -1368,6 +1502,7 @@ fn build_gallery_page() -> (
         gtk4::Button,
         gtk4::GridView,
         gtk4::Button,
+        gtk4::Button, // Upload Photo
     ),
 ) {
     let model = gio::ListStore::new::<BoxedAnyObject>();
@@ -1429,21 +1564,41 @@ fn build_gallery_page() -> (
         .child(&grid)
         .build();
 
+    // Modern header: "Photos" title + "Upload Photo" action button
+    let header_box = gtk4::Box::new(gtk4::Orientation::Horizontal, 8);
+    let title_label = gtk4::Label::builder()
+        .label("Photos")
+        .halign(gtk4::Align::Start)
+        .hexpand(true)
+        .build();
+    title_label.add_css_class("heading");
+
+    let upload = gtk4::Button::builder()
+        .label("Upload Photo")
+        .icon_name("list-add-symbolic")
+        .valign(gtk4::Align::Center)
+        .build();
+    upload.add_css_class("pill");
+    upload.add_css_class("suggested-action");
+    header_box.append(&title_label);
+    header_box.append(&upload);
+
     let inner = gtk4::Box::new(gtk4::Orientation::Vertical, 12);
     inner.set_margin_top(12);
     inner.set_margin_bottom(12);
     inner.set_margin_start(12);
     inner.set_margin_end(12);
+    inner.append(&header_box);
     inner.append(&status);
     inner.append(&retry);
     inner.append(&scroll);
     inner.append(&more);
 
-    (inner.upcast(), (model, status, more, grid, retry))
+    (inner.upcast(), (model, status, more, grid, retry, upload))
 }
 
-/// Wire the gallery: activating a tile downloads the photo and opens it; the
-/// "Load more" button appends the next page.
+/// Wire the gallery: activating a tile downloads the photo and opens it in our
+/// in-app lightbox viewer; the "Load more" button appends the next page.
 fn wire_gallery(ui: &Rc<Ui>, grid: &gtk4::GridView) {
     let ui_open = ui.clone();
     grid.connect_activate(move |grid, pos| {
@@ -1454,34 +1609,513 @@ fn wire_gallery(ui: &Rc<Ui>, grid: &gtk4::GridView) {
             .downcast_ref::<BoxedAnyObject>()
             .map(|o| o.borrow::<PhotoItem>().uid.clone());
         let Some(uid) = uid else { return };
-        // Ignore a repeat activation of a photo already downloading.
-        if !ui_open.opening.borrow_mut().insert(uid.clone()) {
-            return;
-        }
-        ui_open.busy_begin();
-        let rx = spawn_request(
-            ui_open.dirs.control_socket(),
-            Request::OpenPhoto { uid: uid.clone() },
-        );
-        let ui = ui_open.clone();
-        glib::spawn_future_local(async move {
-            let result = rx.recv().await;
-            ui.busy_end();
-            ui.opening.borrow_mut().remove(&uid);
-            match result {
-                Ok(Ok(Response::FilePath { path })) => open_path(&path),
-                Ok(Ok(Response::Error { message })) => {
-                    tracing::error!("open photo failed: {message}")
-                }
-                _ => tracing::error!("open photo request failed"),
-            }
-        });
+        open_photo_viewer(&ui_open, uid);
     });
 
     let ui_more = ui.clone();
     ui.gallery_more.clone().connect_clicked(move |_| {
         load_gallery(&ui_more, true);
     });
+
+    let ui_upload = ui.clone();
+    ui.gallery_upload.connect_clicked(move |_| {
+        let dialog = gtk4::FileDialog::builder()
+            .title("Select Photo to Upload")
+            .build();
+
+        let filter = gtk4::FileFilter::new();
+        filter.set_name(Some("Images"));
+        filter.add_mime_type("image/*");
+        let filters = gio::ListStore::new::<gtk4::FileFilter>();
+        filters.append(&filter);
+        dialog.set_filters(Some(&filters));
+
+        let ui = ui_upload.clone();
+        let parent_win = ui.stack.root().and_downcast::<gtk4::Window>();
+        dialog.open(parent_win.as_ref(), gio::Cancellable::NONE, move |res| {
+            if let Ok(file) = res {
+                if let Some(path) = file.path() {
+                    let name = path
+                        .file_name()
+                        .and_then(|n| n.to_str())
+                        .unwrap_or("photo.jpg")
+                        .to_string();
+                    let bytes = match std::fs::read(&path) {
+                        Ok(b) => b,
+                        Err(e) => {
+                            tracing::error!("Failed to read photo: {e}");
+                            return;
+                        }
+                    };
+                    let ext = path
+                        .extension()
+                        .and_then(|e| e.to_str())
+                        .unwrap_or("jpg")
+                        .to_lowercase();
+                    let media_type = match ext.as_str() {
+                        "png" => "image/png",
+                        "gif" => "image/gif",
+                        "webp" => "image/webp",
+                        "tiff" | "tif" => "image/tiff",
+                        _ => "image/jpeg",
+                    };
+                    let capture_time = std::fs::metadata(&path)
+                        .and_then(|m| m.modified())
+                        .ok()
+                        .and_then(|t| t.duration_since(std::time::SystemTime::UNIX_EPOCH).ok())
+                        .map(|d| d.as_secs() as i64);
+
+                    ui.busy_begin();
+                    let rx = spawn_request(
+                        ui.dirs.control_socket(),
+                        Request::UploadPhoto {
+                            name,
+                            media_type: media_type.to_string(),
+                            bytes,
+                            capture_time,
+                        },
+                    );
+                    let ui_clone = ui.clone();
+                    glib::spawn_future_local(async move {
+                        let res = rx.recv().await;
+                        ui_clone.busy_end();
+                        match res {
+                            Ok(Ok(Response::Ok { message })) => {
+                                tracing::info!("Photo uploaded: {message}");
+                                load_gallery(&ui_clone, false);
+                            }
+                            Ok(Ok(Response::Error { message })) => {
+                                tracing::error!("Upload failed: {message}");
+                                show_error_dialog(&ui_clone, &format!("Upload failed: {message}"));
+                            }
+                            _ => {
+                                tracing::error!("Upload request failed");
+                                show_error_dialog(
+                                    &ui_clone,
+                                    "Upload request failed (daemon unreachable).",
+                                );
+                            }
+                        }
+                    });
+                }
+            }
+        });
+    });
+}
+
+fn show_error_dialog(ui: &Rc<Ui>, message: &str) {
+    let parent = ui.stack.root().and_downcast::<gtk4::Window>();
+    let dialog = adw::AlertDialog::builder()
+        .heading("Photo Operation")
+        .body(message)
+        .build();
+    dialog.add_response("ok", "OK");
+    dialog.present(parent.as_ref());
+}
+
+fn find_photo_index(model: &gio::ListStore, uid: &str) -> Option<u32> {
+    for i in 0..model.n_items() {
+        if let Some(obj) = model.item(i) {
+            if let Some(boxed) = obj.downcast_ref::<BoxedAnyObject>() {
+                if boxed.borrow::<PhotoItem>().uid == uid {
+                    return Some(i);
+                }
+            }
+        }
+    }
+    None
+}
+
+fn format_capture_time(secs: i64) -> String {
+    let date = glib::DateTime::from_unix_local(secs);
+    match date {
+        Ok(d) => match d.format("%Y-%m-%d %H:%M:%S") {
+            Ok(s) => s.to_string(),
+            Err(_) => "Unknown Date".to_string(),
+        },
+        Err(_) => "Unknown Date".to_string(),
+    }
+}
+
+fn load_photo(
+    ui: &Rc<Ui>,
+    uid: String,
+    picture: &gtk4::Picture,
+    spinner: &gtk4::Spinner,
+    status_label: &gtk4::Label,
+    current_path: Rc<RefCell<Option<String>>>,
+) {
+    spinner.set_visible(true);
+    spinner.start();
+    picture.set_paintable(gtk4::gdk::Paintable::NONE);
+    status_label.set_visible(false);
+    *current_path.borrow_mut() = None;
+
+    let rx = spawn_request(
+        ui.dirs.control_socket(),
+        Request::OpenPhoto { uid: uid.clone() },
+    );
+    let picture_clone = picture.clone();
+    let spinner_clone = spinner.clone();
+    let status_clone = status_label.clone();
+    glib::spawn_future_local(async move {
+        let result = rx.recv().await;
+        spinner_clone.stop();
+        spinner_clone.set_visible(false);
+        match result {
+            Ok(Ok(Response::FilePath { path })) => match gtk4::gdk::Texture::from_filename(&path) {
+                Ok(texture) => {
+                    picture_clone.set_paintable(Some(&texture));
+                    *current_path.borrow_mut() = Some(path);
+                }
+                Err(e) => {
+                    status_clone.set_label(&format!("Failed to load image: {e}"));
+                    status_clone.set_visible(true);
+                }
+            },
+            Ok(Ok(Response::Error { message })) => {
+                status_clone.set_label(&format!("Error downloading photo: {message}"));
+                status_clone.set_visible(true);
+            }
+            _ => {
+                status_clone.set_label("Failed to connect to daemon");
+                status_clone.set_visible(true);
+            }
+        }
+    });
+}
+
+fn save_photo_to_disk(window: &gtk4::Window, source_path: &str, original_name: &str) {
+    let dialog = gtk4::FileDialog::builder()
+        .title("Save Photo")
+        .initial_name(original_name)
+        .build();
+    let source_path_str = source_path.to_string();
+    dialog.save(Some(window), gio::Cancellable::NONE, move |res| {
+        if let Ok(file) = res {
+            if let Some(dest_path) = file.path() {
+                if let Err(e) = std::fs::copy(&source_path_str, &dest_path) {
+                    tracing::error!("Failed to copy file to {:?}: {}", dest_path, e);
+                } else {
+                    tracing::info!("Saved photo to {:?}", dest_path);
+                }
+            }
+        }
+    });
+}
+
+fn navigate_photo(
+    ui: &Rc<Ui>,
+    current_uid: &Rc<RefCell<String>>,
+    delta: i32,
+    picture: &gtk4::Picture,
+    spinner: &gtk4::Spinner,
+    status_label: &gtk4::Label,
+    title_label: &gtk4::Label,
+    prev_btn: &gtk4::Button,
+    next_btn: &gtk4::Button,
+    current_path: Rc<RefCell<Option<String>>>,
+) {
+    let model = &ui.gallery_model;
+    let n = model.n_items();
+    if n == 0 {
+        return;
+    }
+    let uid_val = current_uid.borrow().clone();
+    let current_idx = find_photo_index(model, &uid_val).unwrap_or(0);
+    let next_idx = (current_idx as i32 + delta).clamp(0, n as i32 - 1) as u32;
+
+    let Some(obj) = model.item(next_idx) else {
+        return;
+    };
+    let Some(boxed) = obj.downcast_ref::<BoxedAnyObject>() else {
+        return;
+    };
+    let photo = boxed.borrow::<PhotoItem>().clone();
+
+    *current_uid.borrow_mut() = photo.uid.clone();
+
+    prev_btn.set_sensitive(next_idx > 0);
+    next_btn.set_sensitive(next_idx < n - 1);
+
+    let date_str = format_capture_time(photo.capture_time);
+    title_label.set_label(&format!("Photo {} of {} • {}", next_idx + 1, n, date_str));
+
+    load_photo(
+        ui,
+        photo.uid.clone(),
+        picture,
+        spinner,
+        status_label,
+        current_path,
+    );
+}
+
+fn open_photo_viewer(ui: &Rc<Ui>, initial_uid: String) {
+    let parent = ui.stack.root().and_downcast::<gtk4::Window>().unwrap();
+
+    let window = gtk4::Window::builder()
+        .title("Photo Viewer")
+        .modal(true)
+        .transient_for(&parent)
+        .default_width(800)
+        .default_height(600)
+        .build();
+    window.add_css_class("photo-viewer-window");
+
+    let overlay = gtk4::Overlay::new();
+
+    let picture = gtk4::Picture::builder()
+        .content_fit(gtk4::ContentFit::Contain)
+        .hexpand(true)
+        .vexpand(true)
+        .build();
+    overlay.set_child(Some(&picture));
+
+    let prev_btn = gtk4::Button::builder()
+        .icon_name("go-previous-symbolic")
+        .tooltip_text("Previous Photo")
+        .halign(gtk4::Align::Start)
+        .valign(gtk4::Align::Center)
+        .build();
+    prev_btn.add_css_class("circular");
+    prev_btn.add_css_class("flat");
+    prev_btn.add_css_class("viewer-nav-btn");
+    overlay.add_overlay(&prev_btn);
+
+    let next_btn = gtk4::Button::builder()
+        .icon_name("go-next-symbolic")
+        .tooltip_text("Next Photo")
+        .halign(gtk4::Align::End)
+        .valign(gtk4::Align::Center)
+        .build();
+    next_btn.add_css_class("circular");
+    next_btn.add_css_class("flat");
+    next_btn.add_css_class("viewer-nav-btn");
+    overlay.add_overlay(&next_btn);
+
+    let top_bar = gtk4::Box::new(gtk4::Orientation::Horizontal, 8);
+    top_bar.add_css_class("viewer-top-bar");
+    top_bar.set_valign(gtk4::Align::Start);
+    top_bar.set_hexpand(true);
+
+    let title_label = gtk4::Label::builder()
+        .halign(gtk4::Align::Start)
+        .hexpand(true)
+        .ellipsize(gtk4::pango::EllipsizeMode::End)
+        .build();
+    title_label.add_css_class("viewer-title");
+    top_bar.append(&title_label);
+
+    let download_btn = gtk4::Button::builder()
+        .icon_name("document-save-symbolic")
+        .tooltip_text("Download to Disk")
+        .build();
+    download_btn.add_css_class("flat");
+    download_btn.add_css_class("viewer-action-btn");
+    top_bar.append(&download_btn);
+
+    let open_ext_btn = gtk4::Button::builder()
+        .icon_name("document-open-symbolic")
+        .tooltip_text("Open in External App")
+        .build();
+    open_ext_btn.add_css_class("flat");
+    open_ext_btn.add_css_class("viewer-action-btn");
+    top_bar.append(&open_ext_btn);
+
+    let close_btn = gtk4::Button::builder()
+        .icon_name("window-close-symbolic")
+        .tooltip_text("Close")
+        .build();
+    close_btn.add_css_class("flat");
+    close_btn.add_css_class("viewer-action-btn");
+    top_bar.append(&close_btn);
+
+    overlay.add_overlay(&top_bar);
+
+    let spinner = gtk4::Spinner::builder()
+        .halign(gtk4::Align::Center)
+        .valign(gtk4::Align::Center)
+        .width_request(48)
+        .height_request(48)
+        .build();
+    overlay.add_overlay(&spinner);
+
+    let status_label = gtk4::Label::builder()
+        .wrap(true)
+        .justify(gtk4::Justification::Center)
+        .halign(gtk4::Align::Center)
+        .valign(gtk4::Align::Center)
+        .build();
+    status_label.add_css_class("viewer-status");
+    overlay.add_overlay(&status_label);
+
+    window.set_child(Some(&overlay));
+
+    let current_uid = Rc::new(RefCell::new(initial_uid.clone()));
+    let current_path = Rc::new(RefCell::new(None::<String>));
+
+    let n = ui.gallery_model.n_items();
+    let initial_idx = find_photo_index(&ui.gallery_model, &initial_uid).unwrap_or(0);
+    prev_btn.set_sensitive(initial_idx > 0);
+    next_btn.set_sensitive(initial_idx < n - 1);
+
+    let mut initial_capture_time = 0;
+    if let Some(obj) = ui.gallery_model.item(initial_idx) {
+        if let Some(boxed) = obj.downcast_ref::<BoxedAnyObject>() {
+            initial_capture_time = boxed.borrow::<PhotoItem>().capture_time;
+        }
+    }
+    let date_str = format_capture_time(initial_capture_time);
+    title_label.set_label(&format!(
+        "Photo {} of {} • {}",
+        initial_idx + 1,
+        n,
+        date_str
+    ));
+
+    load_photo(
+        ui,
+        initial_uid,
+        &picture,
+        &spinner,
+        &status_label,
+        current_path.clone(),
+    );
+
+    let w_close = window.clone();
+    close_btn.connect_clicked(move |_| {
+        w_close.close();
+    });
+
+    let w_download = window.clone();
+    let path_download = current_path.clone();
+    let uid_download = current_uid.clone();
+    download_btn.connect_clicked(move |_| {
+        if let Some(path) = path_download.borrow().as_deref() {
+            let uid_val = uid_download.borrow();
+            let name = format!("{}.jpg", uid_val);
+            save_photo_to_disk(&w_download, path, &name);
+        }
+    });
+
+    let path_ext = current_path.clone();
+    open_ext_btn.connect_clicked(move |_| {
+        if let Some(path) = path_ext.borrow().as_deref() {
+            open_path(path);
+        }
+    });
+
+    let ui_prev = ui.clone();
+    let uid_prev = current_uid.clone();
+    let pic_prev = picture.clone();
+    let spin_prev = spinner.clone();
+    let status_prev = status_label.clone();
+    let title_prev = title_label.clone();
+    let p_btn = prev_btn.clone();
+    let n_btn = next_btn.clone();
+    let path_prev = current_path.clone();
+    prev_btn.connect_clicked(move |_| {
+        navigate_photo(
+            &ui_prev,
+            &uid_prev,
+            -1,
+            &pic_prev,
+            &spin_prev,
+            &status_prev,
+            &title_prev,
+            &p_btn,
+            &n_btn,
+            path_prev.clone(),
+        );
+    });
+
+    let ui_next = ui.clone();
+    let uid_next = current_uid.clone();
+    let pic_next = picture.clone();
+    let spin_next = spinner.clone();
+    let status_next = status_label.clone();
+    let title_next = title_label.clone();
+    let p_btn = prev_btn.clone();
+    let n_btn = next_btn.clone();
+    let path_next = current_path.clone();
+    next_btn.connect_clicked(move |_| {
+        navigate_photo(
+            &ui_next,
+            &uid_next,
+            1,
+            &pic_next,
+            &spin_next,
+            &status_next,
+            &title_next,
+            &p_btn,
+            &n_btn,
+            path_next.clone(),
+        );
+    });
+
+    let key_controller = gtk4::EventControllerKey::new();
+    let ui_key = ui.clone();
+    let uid_key = current_uid.clone();
+    let pic_key = picture.clone();
+    let spin_key = spinner.clone();
+    let status_key = status_label.clone();
+    let title_key = title_label.clone();
+    let p_btn = prev_btn.clone();
+    let n_btn = next_btn.clone();
+    let path_key = current_path.clone();
+    let w_key = window.clone();
+    key_controller.connect_key_pressed(move |_, key, _keycode, _state| {
+        match key.name().as_deref() {
+            Some("Left") => {
+                let current_idx =
+                    find_photo_index(&ui_key.gallery_model, &uid_key.borrow()).unwrap_or(0);
+                if current_idx > 0 {
+                    navigate_photo(
+                        &ui_key,
+                        &uid_key,
+                        -1,
+                        &pic_key,
+                        &spin_key,
+                        &status_key,
+                        &title_key,
+                        &p_btn,
+                        &n_btn,
+                        path_key.clone(),
+                    );
+                }
+                glib::Propagation::Stop
+            }
+            Some("Right") => {
+                let n = ui_key.gallery_model.n_items();
+                let current_idx =
+                    find_photo_index(&ui_key.gallery_model, &uid_key.borrow()).unwrap_or(0);
+                if current_idx < n - 1 {
+                    navigate_photo(
+                        &ui_key,
+                        &uid_key,
+                        1,
+                        &pic_key,
+                        &spin_key,
+                        &status_key,
+                        &title_key,
+                        &p_btn,
+                        &n_btn,
+                        path_key.clone(),
+                    );
+                }
+                glib::Propagation::Stop
+            }
+            Some("Escape") => {
+                w_key.close();
+                glib::Propagation::Stop
+            }
+            _ => glib::Propagation::Proceed,
+        }
+    });
+    window.add_controller(key_controller);
+
+    window.present();
 }
 
 /// Fetch a timeline page from the daemon. When `append` is false the model is