feat: persist and restore TUI state across restarts

The main TUI now loads state on startup — search history restored as
inert entries, saved chat rooms rejoined on the server, and incomplete
downloads (including failed/timed-out ones) automatically re-enqueued —
and saves a diffed snapshot each loop tick and on exit, so only changed
files are rewritten.

soulseek-rs/src/main.rs

@@ -243,12 +243,16 @@ fn run_default_tui(
 
     persist_credentials(&outcome, config_path, file_config, &secret_store);
 
+    let store = persist::paths::state_dir()
+        .map(persist::state::StateStore::new);
+
     launch_main_tui(
         terminal,
         Arc::new(outcome.client),
         resolved.download_dir.clone(),
         resolved.max_concurrent_downloads,
         Duration::from_secs(resolved.search_timeout),
+        store,
     )
 }
 

soulseek-rs/src/persist/mod.rs

@@ -7,4 +7,5 @@
 pub mod config;
 pub mod paths;
 pub mod secret;
+pub mod snapshot;
 pub mod state;

soulseek-rs/src/persist/snapshot.rs

@@ -0,0 +1,187 @@
+//! Capture the persistable slice of [`AppState`] (and restore the pure
+//! parts of it). Live handles (channels, cancel flags) never leave the
+//! process; only plain data goes to disk.
+
+use super::state::PersistedDownload;
+use crate::models::{AppState, SearchEntry, SearchStatus};
+use soulseek_rs::DownloadStatus;
+
+#[derive(Debug, Clone, PartialEq, Eq, Default)]
+pub struct Snapshot {
+    pub downloads: Vec<PersistedDownload>,
+    pub queries: Vec<String>,
+    pub rooms: Vec<String>,
+}
+
+impl Snapshot {
+    /// Extract what should survive a restart. Downloads that are not yet
+    /// `Completed` (including failed/timed-out ones) are marked incomplete
+    /// so the next start can re-enqueue them.
+    pub fn capture(state: &AppState) -> Self {
+        let downloads = state
+            .downloads
+            .iter()
+            .map(|entry| PersistedDownload {
+                username: entry.download.username.clone(),
+                filename: entry.download.filename.clone(),
+                size: entry.download.size,
+                download_directory: entry
+                    .download
+                    .download_directory
+                    .clone(),
+                completed: matches!(
+                    entry.download.status,
+                    DownloadStatus::Completed
+                ),
+            })
+            .collect();
+
+        let mut queries: Vec<String> = Vec::new();
+        for entry in &state.searches {
+            if !queries.contains(&entry.query) {
+                queries.push(entry.query.clone());
+            }
+        }
+
+        let rooms =
+            state.rooms.open.iter().map(|room| room.name.clone()).collect();
+
+        Self {
+            downloads,
+            queries,
+            rooms,
+        }
+    }
+}
+
+/// Rebuild search history entries from persisted query strings. Restored
+/// searches are inert (completed, no results) — selecting one shows an
+/// empty result set until it is re-run.
+pub fn restore_searches(state: &mut AppState, queries: &[String]) {
+    for query in queries {
+        state.searches.push(SearchEntry {
+            query: query.clone(),
+            status: SearchStatus::Completed,
+            results: Vec::new(),
+            start_time: std::time::Instant::now(),
+            cancel_flag: std::sync::Arc::new(
+                std::sync::atomic::AtomicBool::new(false),
+            ),
+        });
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::models::DownloadEntry;
+    use soulseek_rs::types::{Download, DownloadMetadata};
+    use std::sync::atomic::AtomicBool;
+    use std::sync::{Arc, mpsc};
+    use std::time::Instant;
+
+    fn download(
+        filename: &str,
+        status: DownloadStatus,
+    ) -> DownloadEntry {
+        let (sender, _receiver) = mpsc::channel();
+        DownloadEntry {
+            download: Download {
+                username: "peer".into(),
+                filename: filename.into(),
+                token: 7,
+                size: 42,
+                download_directory: "/music".into(),
+                status,
+                sender,
+                queue_position: None,
+                metadata: DownloadMetadata::default(),
+            },
+            receiver: None,
+        }
+    }
+
+    fn search(query: &str) -> SearchEntry {
+        SearchEntry {
+            query: query.into(),
+            status: SearchStatus::Active,
+            results: Vec::new(),
+            start_time: Instant::now(),
+            cancel_flag: Arc::new(AtomicBool::new(false)),
+        }
+    }
+
+    #[test]
+    fn capture_maps_download_status_to_completed_flag() {
+        let mut state = AppState::new();
+        state.downloads.push(download("done.mp3", DownloadStatus::Completed));
+        state.downloads.push(download("queued.mp3", DownloadStatus::Queued));
+        state.downloads.push(download(
+            "failed.mp3",
+            DownloadStatus::Failed(Some("nope".into())),
+        ));
+
+        let snapshot = Snapshot::capture(&state);
+        assert_eq!(
+            snapshot
+                .downloads
+                .iter()
+                .map(|d| (d.filename.as_str(), d.completed))
+                .collect::<Vec<_>>(),
+            vec![
+                ("done.mp3", true),
+                ("queued.mp3", false),
+                ("failed.mp3", false)
+            ]
+        );
+        assert_eq!(snapshot.downloads[0].username, "peer");
+        assert_eq!(snapshot.downloads[0].size, 42);
+        assert_eq!(snapshot.downloads[0].download_directory, "/music");
+    }
+
+    #[test]
+    fn capture_takes_queries_in_order_without_duplicates() {
+        let mut state = AppState::new();
+        state.searches.push(search("beatles"));
+        state.searches.push(search("miles davis"));
+        state.searches.push(search("beatles"));
+        let snapshot = Snapshot::capture(&state);
+        assert_eq!(
+            snapshot.queries,
+            vec!["beatles".to_string(), "miles davis".to_string()]
+        );
+    }
+
+    #[test]
+    fn capture_takes_open_room_names() {
+        let mut state = AppState::new();
+        state.rooms.focus_or_open("indie");
+        state.rooms.focus_or_open("jazz");
+        let snapshot = Snapshot::capture(&state);
+        assert_eq!(
+            snapshot.rooms,
+            vec!["indie".to_string(), "jazz".to_string()]
+        );
+    }
+
+    #[test]
+    fn restore_searches_creates_inert_completed_entries() {
+        let mut state = AppState::new();
+        restore_searches(
+            &mut state,
+            &["beatles".to_string(), "miles davis".to_string()],
+        );
+        assert_eq!(state.searches.len(), 2);
+        assert_eq!(state.searches[0].query, "beatles");
+        assert_eq!(state.searches[0].status, SearchStatus::Completed);
+        assert!(state.searches[0].results.is_empty());
+    }
+
+    #[test]
+    fn capture_of_restored_searches_round_trips() {
+        let mut state = AppState::new();
+        restore_searches(&mut state, &["beatles".to_string()]);
+        let snapshot = Snapshot::capture(&state);
+        assert_eq!(snapshot.queries, vec!["beatles".to_string()]);
+    }
+}

soulseek-rs/src/ui/main_tui/mod.rs

@@ -6,6 +6,10 @@ mod rooms;
 mod search;
 
 use crate::models::AppState;
+use crate::persist::{
+    snapshot::{Snapshot, restore_searches},
+    state::StateStore,
+};
 use color_eyre::Result;
 use ratatui::{
     DefaultTerminal,
@@ -22,6 +26,9 @@ pub struct MainTui {
     max_concurrent_downloads: usize,
     search_timeout: Duration,
     spinner_state: usize,
+    store: Option<StateStore>,
+    /// Last snapshot written to disk, to skip no-op saves.
+    saved_snapshot: Snapshot,
 }
 
 impl MainTui {
@@ -30,15 +37,107 @@ impl MainTui {
         download_dir: String,
         max_concurrent_downloads: usize,
         search_timeout: Duration,
+        store: Option<StateStore>,
     ) -> Self {
-        Self {
+        let mut tui = Self {
             client,
             state: AppState::new(),
             download_dir,
             max_concurrent_downloads,
             search_timeout,
             spinner_state: 0,
+            store,
+            saved_snapshot: Snapshot::default(),
+        };
+        tui.restore_persisted_state();
+        tui
     }
+
+    /// Bring back last session's state: search history, chat rooms
+    /// (rejoined on the server), and downloads — incomplete ones are
+    /// re-enqueued so they resume automatically.
+    fn restore_persisted_state(&mut self) {
+        let Some(store) = &self.store else { return };
+
+        restore_searches(&mut self.state, &store.load_search_queries());
+
+        for room in store.load_rooms() {
+            if self.state.rooms.focus_or_open(&room)
+                && let Err(e) = self.client.join_room(&room)
+            {
+                soulseek_rs::warn!("Could not rejoin {room}: {e}");
+            }
+        }
+
+        let downloads = store.load_downloads();
+        self.saved_snapshot = Snapshot::capture(&self.state);
+        // Completed entries are shown as-is; the rest re-enqueue below and
+        // reappear through the normal downloads channel.
+        self.saved_snapshot.downloads.clone_from(&downloads);
+
+        let sender = self.downloads_sender();
+        for entry in downloads {
+            if entry.completed {
+                self.state.downloads.push(crate::models::DownloadEntry {
+                    download: soulseek_rs::types::Download {
+                        username: entry.username,
+                        filename: entry.filename,
+                        token: 0,
+                        size: entry.size,
+                        download_directory: entry.download_directory,
+                        status: soulseek_rs::DownloadStatus::Completed,
+                        sender: std::sync::mpsc::channel().0,
+                        queue_position: None,
+                        metadata: Default::default(),
+                    },
+                    receiver: None,
+                });
+            } else {
+                let client = self.client.clone();
+                let sender = sender.clone();
+                std::thread::spawn(move || {
+                    match client.download(
+                        entry.filename.clone(),
+                        entry.username,
+                        entry.size,
+                        entry.download_directory,
+                    ) {
+                        Ok((download, rx)) => {
+                            let _ = sender.send((download, rx));
+                        }
+                        Err(e) => soulseek_rs::warn!(
+                            "Could not resume {}: {e}",
+                            entry.filename
+                        ),
+                    }
+                });
+            }
+        }
+    }
+
+    /// Write state to disk when it differs from what was last saved.
+    fn save_persisted_state(&mut self) {
+        let Some(store) = &self.store else { return };
+        let snapshot = Snapshot::capture(&self.state);
+        if snapshot == self.saved_snapshot {
+            return;
+        }
+        if snapshot.downloads != self.saved_snapshot.downloads
+            && let Err(e) = store.save_downloads(&snapshot.downloads)
+        {
+            soulseek_rs::warn!("Could not save downloads state: {e}");
+        }
+        if snapshot.queries != self.saved_snapshot.queries
+            && let Err(e) = store.save_search_queries(&snapshot.queries)
+        {
+            soulseek_rs::warn!("Could not save search history: {e}");
+        }
+        if snapshot.rooms != self.saved_snapshot.rooms
+            && let Err(e) = store.save_rooms(&snapshot.rooms)
+        {
+            soulseek_rs::warn!("Could not save room state: {e}");
+        }
+        self.saved_snapshot = snapshot;
     }
 
     pub fn run(mut self, mut terminal: DefaultTerminal) -> Result<()> {
@@ -49,6 +148,7 @@ impl MainTui {
         // of raw mode / the alternate screen and mouse capture disabled, or the
         // user is left with a corrupted terminal.
         let result = self.run_event_loop(&mut terminal);
+        self.save_persisted_state();
 
         let _ = execute!(std::io::stdout(), DisableMouseCapture);
         ratatui::restore();
@@ -78,6 +178,8 @@ impl MainTui {
 
             self.spinner_state = (self.spinner_state + 1) % 10;
 
+            self.save_persisted_state();
+
             // Drain every queued input event before the next draw: key
             // autorepeat outpaces the frame time, and handling one event per
             // frame makes the backlog keep scrolling for seconds after the
@@ -110,12 +212,14 @@ pub fn launch_main_tui(
     download_dir: String,
     max_concurrent_downloads: usize,
     search_timeout: Duration,
+    store: Option<StateStore>,
 ) -> Result<()> {
     let tui = MainTui::new(
         client,
         download_dir,
         max_concurrent_downloads,
         search_timeout,
+        store,
     );
     tui.run(terminal)
 }