sync_replay_project/docs/ROADMAP.md

Roadmap

Backlog and epics, in order. Done work lives in git history. Check an item off by deleting it in the same commit as the code. Wire changes also edit PROTOCOL.md.

Stabilisation (feature freeze)

No new systems or features until the app is stable on a proper architecture. The next release is the restructure (1.3.0, or 2.0.0). Problems are numbered; delete a line when its fix ships.

Decisions (agreed):

• D1 Presence: In (watching, full), Away (sat out: still in the server, chat and chosen notifications, system notifications in the background, not counted for the gate, ready counter or watched tracking), Gone (disconnected, held in a grace period).
• D2 A joiner during playback does not pause it: they load in the background and join already in sync (a pause also works, no pause is cleaner).
• D3 Watched: at least as good as Jellyfin's own; a peek, skipping around or a screenshot visit never counts. Basis: time present while it played.
• D4 Toasts above the control bar; toasts for joins/leaves, queue adds (title, picture, who), swaps, problems; the rest in the activity log. Chat pop-ups and their sound always on by default; only the unread badge stays off the picture.
• D5 A reconnect resumes the same member within a grace period (~10 min).
• D6 The person passing a video on drops: others keep playing; on reconnect the relay continues from where it was.
• D7 One controls model, two skins (done in 1.2.1-dev.1); uosc credited.
• D8 Always the latest version: automatic checks, a clear prompt (no background download), never during playback.
• D9 Watching alone is a full standalone player: no social sounds or prompts; social parts appear when others are there; no solo mode.
• D11 Login-only sites: error texts say which cookies were used.

Problems:

• P2 Viewers of a relay whose source is gone: mpv loops on failed seeks past what the server buffered (viewer-side recovery, step 5).
• P7 Sat-out people get tracked as watched on Jellyfin.
• P8 Sat-out people get the normal notifications.
• P9 The watched rule (position coverage) misses real watches (D3).
• P11 Toasts cover the video controls.
• P12 Queue additions don't show as toasts.
• P15 Commands reach a player mid-switch (seek 90.0, event:5 errors).
• P17 Preload, warm relay and the fresh player per video are layered on the player instead of being one media pipeline.
• P18 Bilibili "no video formats" with browser cookies set; the hint wording misleads (D11).
• P22 Friends on different versions (D8). (P20 version visible and P21 update band: fixed in 1.2.1-dev.3; check the band in real use.)
• P23 Solo mode you enter and leave; going hosted loses the queue (D9).
• P24 The invite address list is unhelpful (shows the proxy's 198.18.x).
• P25 ssh to Gitea blocked through the proxy (pushes go over https).
• P28 Log noise: "Failed to create file cache"; an idle relay channel for Jellyfin items everyone has an account for.
• P29 Relay start delay after a seek into an unbuffered part.
• P30 Shaders don't work on Windows. Fix in 1.2.1-dev.3 (list read-back check; Windows hwdec auto-copy): a Windows user must confirm shaders stay on and the EGL-surface error is gone.
• P31 Software rendering on a friend's Linux. 1.2.1-dev.3 logs it (mpv: render lines); needs that friend's log, plus watch-together 2>&1 | grep VideoOutput from a terminal if software.
• P32 The app freezes on exit, mostly reported on Windows. 1.2.1-dev.3: orderly close, Linux _exit (0 crashes in 41 closes vs 10/10 before), Windows normal close + TerminateProcess + watchdogs, untested on Windows; if it still hangs: Event Viewer 1000/1002, a Task Manager dump, the close: log lines.
• P33 No volume readout on wheel: likely fixed by the controls rework (1.2.1-dev.1; a test covers both skins); confirm in real use.
• P34 Local anime folders are opened as plain files (no banner, names, next episode, tracking); test library: the user's /mnt/torrents/Torrents/Binux/ (several shows and a movie).

Restructure (in order; reviewed against the code). Truth lives in three places: the server (members, presence, gate, transport, queue incl. the automatic continuation and countdown, relay state), the device (client id, library and folders, match corrections, watch history, settings, notification prefs, what this app is sourcing) and the integrations (Jellyfin played/resume, AniList list). 2. Status (one computed level, incl. the server's hold reason) + Notifier (noticeFor(event, context): self presence, alone, window activity, playing, prefs, replayed; owns its toast timer; system notifications port; library snack bars moved in). Fixes P8 P11 P12 P21 P33, "source left"; D4, D1 notifications, D9 alone policy (isAlone in core). Step 1 left over for it: the presence notices are today's (sat you out, a toast when auto sit-out sets you away, lost signal and return only in the activity log); a replayed feed only logs. 3. Your server: one hub, listeners attached and detached without members reconnecting (old isolate path kept until that's proven); Invite as a value (filtered addresses, version gate from /health.version, an fp field reserved for pinned certificates later); SessionState is deleted here. Fixes P22 P23 P24; D9. 4. Library + Media identity: L1 local grouping (kinds, folder hints, gaps, merge across folders) and L2 match (AniList/TVDB, art, names, manual pin, cache); MediaRef in swap/queue media. Fixes P34. 5. Media pipeline + player host port: plan → resolve → open → ready, commands queued during a switch, viewer-side recovery when a source drops (no mpv seek loops, play what's buffered), resolver and source chosen by capability; a Windows CI smoke job (start, open, close within N s, no orphan process). Fixes P2 P15 P17 P18 P28 P29, P30–P32; D11. 6. What's next (decides which/when, asks the pipeline to prepare; continuation and countdown as server state, shared cancel) + Watch tracking (time In from the presence history, device history, Jellyfin now, AniList later). Fixes P7 P9; D3. 7. Release 1.3.0: publish the manifest (protocol 16 makes it a required update for 1.2.x) and update the VPS dedicated server in the same window; check a 1.2.x app gets a clear "update the app" message. Composition root: an AppGraph built in main.dart only constructs and disposes systems (no logic, no signals); systems get dependencies through constructors, widgets through one AppScope; a test fails if the count of .instance singletons grows (today: SessionState 94, AppSettings 51, JellyfinAccounts 10, Profile 7). Not in the restructure: P25 (ops).

Agreed since: the queue stays in memory (no server storage). Transport: wss:// preferred when a server offers it, ws:// still allowed (a cleartext exception on Android); it only carries sync. Tests: many pin behaviour the restructure drops; each is tagged with the step that rewrites it, and the safety-net scenarios (DEVELOPMENT "Tests") must keep passing through every step. Open questions below are decided during the restructure. How: incremental on main (one system extracted per step, every dev build usable), signals plus constructor wiring through one composition root (no new framework), dev builds 1.3.0-dev.N, everyone moves to proto 16 together at the 1.3.0 release. Rooms are out (no room id). No Windows dev builds: restructure testing happens on Linux; Windows friends stay on 1.2.x until the 1.3.0 release (Windows-only fixes like P30 reach them then). Left of the rename (app, binaries, archives and data folder are Starsync): the repository (Foxyz/sync_replay_project) and with it the manifest and asset URLs (a new manifest URL needs a release that reads both first); the dedicated server's fallback folder ~/.cache/watch-together, the release token file ~/.config/watch-together-release-token, Jellyfin's client name "Watch Together" (devices are listed under it) and WatchTogetherApp; dropping the 1.2.x launchers from the archive once nobody updates from 1.2.x. Left of step 1: Update and restart keeps the member gone for the restarted app, but the app starts on Home (it does not rejoin by itself) and does not remember what it was passing on, so a relay it served ends with its grace unless it is put up again; worth doing only if updates ever happen mid-session (D8 says never during playback).

Open decisions:

• Starting together: today someone has to stay unready so others can join first. Ideas: a short "starting in 30 s, ready up" countdown; waiting for everyone from the last session.

• Platform decision: "Desktop + mpv only" becomes "mpv only, desktop first" if Android goes ahead.

• D10 was dropped on purpose (preload/warm relay/fresh player are folded into step 6, not a separate decision).

Protocol 16 (open parts)

Opened in step 1: PROTOCOL.md is proto 16 (version ranges and the refusal frame, error codes and close codes, lasting members by client id with takeover and seq, grace and bye, presence and PresencePolicy, state.hold, feed ids, seq and replay, relay sourceGone and source resume, lasting queue[].by, auto items and cancel, media.ref, members[].app/caps), server, core and app. Still open on the wire, frozen at the 1.3.0 release:

• state.advance (step 6): the server starts the countdown when the media finishes and an item is first, sets queuePlay at its end and holds it while the item's performer or source is gone. Today it is parsed and broadcast but never started; auto items and cancel are live.
• media.ref producers (step 4); the server carries it already.
• hello.client optionally derived per server (HMAC of an install secret and the dialled host:port).
• TLS: /health.tls is always false; wss:// only with a CA-valid certificate in 1.3.0, pinned self-signed via the Invite fp later.
• err code rate: reserved, nothing sends it.

Backlog

1. Auto-skip OP/ED (undecided): who decides and how (shared for the server, personal, per show) is open. Constraint: a skip is a seek and seeks are shared, and only real ranges (segments, OP/ED chapters) should ever be skipped.

2. Files: next episode from Files (by parsed episode, with the countdown, and under Up next's "Continues with"). Later: tracking for file series.

3. yt-dlp follow-ups (see ARCHITECTURE "yt-dlp"): check that the bundled Windows libmpv has the ytdl hook (Lua) and plays edl:// URLs through media_kit; if not, resolve in the app and open the relay tracks' formats. YouTube: yt-dlp wants a JS runtime (deno) for full extraction. Formats that need yt-dlp's cookies.

   • Live streams through the relay (today refused: the sync model needs a fixed duration and seeking).
   • tool/relay_e2e.dart: a two-track case (bytes and pieces) over a shaped source link. Pieces on a slow source: a cold piece can take longer than media_kit's 5 s network-timeout; if it does, fetch the first pieces before setting relay.live.
   • Pieces, unverified so far: the 403/410 re-resolve against a real expiring HLS (signed segment URLs), HLS discontinuities / ad splicing, Windows' bundled ffmpeg with extensionless piece URLs (p/<i>; fine with ffmpeg 9 on Linux).
   • Thumbnails and scrubbing previews of a relayed media with tracks should open the video track's URL alone, not the EDL.

4. AniList account: sign in (OAuth via a localhost callback), "My list" filter on the Schedule from the user's AniList lists. This is the Schedule's personal tracking; AnimeFlow has no per-user follow.

5. Ops: Check shaders on Windows; run the relay e2e "the source drops uncleanly and comes back" a few times under the full suite (its predecessor failed about half the time there).

6. Windows: first real use. Check the rename at 1.3.0: a 1.2.x install updates and restarts (watch_together.exe, a copy of starsync.exe), the data in %APPDATA%\foxyz\Starsync came over from %APPDATA%\com.example\watch_together and Documents, the next update restarts starsync.exe. CI builds and publishes starsync-<ver>-windows-x64.zip (libmpv bundled) and runs the updater tests on NTFS; a friend has joined from it. Still unchecked: fullscreen controls, hosting (firewall prompt), in-app update from one release to the next. The rest of the desktop tests are not in CI.

7. Relay follow-ups (see ARCHITECTURE "Relay"). First real use: owner's PC -> VPS -> friend, Jellyfin and a file. Then:

   • Source takeover: when the source leaves, another member with an account on that Jellyfin (or the same file: name, size, hash) takes over instead of the buffer running dry.
   • "Bob can't open this link — relay it?": offer the relay to whoever put a direct link up when a viewer's player fails to open it.
   • The host's own file as Up next's first item: it plays from /m once up, so others open it cold (the warm relay covers every other relayed item, see ARCHITECTURE "Relay"). The hosting app could hand the server the item's path early and /m serve it under a next/ name until the swap.
   • Research (before building anything): can stream URLs a member's app resolved with yt-dlp (its cookies, its address) be fetched by the server from another address? Per site: YouTube (its googlevideo URLs carry the resolving IP), Bilibili, X, generic HLS/DASH, others; and YouTube resolved by the server itself from a VPS, with and without cookies. Decides whether a server-driven fetch of member-resolved links (the member need not upload or stay) is worth building.

8. Jellyfin (epic, below).

9. Smaller items

   • Video output robustness: if media_kit's hardware path regresses to software (see ARCHITECTURE, Media: render mode), vendor a media_kit_video fix that builds the EGL display from GDK's native display. The video freeze after GPU idle is not explained by this; next suspect is media_kit's context switching on the raster thread with NVIDIA.
   • Link conveniences: a link swap in session updates the remembered media; show the open link with an open-in-browser button.
   • Time UI: remaining time, scrubber preview.
   • mpv / mpv.net shortcut parity.
   • Chaos suite: host drop 5 s / 30 s, viewer stall, 20-seek storm, long outage with cache exhaustion (tool/shaper.dart --kill-after); assert no OOM, no stuck session, drift recovers.
   • Chat history pane (today: activity log only).
   • Images in chat (paste a screenshot; server memory only): possible, not wanted yet.
   • HTTP: move the app's clients (Jellyfin, AniList, AnimeFlow, updater) to dio from fox_utils when touching them, for retries/interceptors.
   • TLS: document a reverse proxy in front of the server.
   • Up next follow-ups (see ARCHITECTURE "Up next"): a whole season or a pick list at once ("Add the rest of the season").
   • Sidecar subtitles.

Epic: Jellyfin

What is left (the rest is in ARCHITECTURE.md, "Jellyfin in a session"):

• Auto-advance cancel for everyone (the next episode and Up next): today Cancel is per screen (the designated swapper's Cancel stops the swap; a seek stops all). The wire has it (queue cancel, state.advance); the app uses it in step 6.
• Sidecar (external) subtitle streams of Jellyfin items: only embedded tracks are mapped to mpv today.

Deferred

P2P, Android. Never: transcoding, web clients.