# VOD Multi-Source Finds the same movie in the user's other imported playlists, lets them switch which one it streams from without losing the timecode, and turns the playback-error screen into a recovery point. The point is not choice for its own sake — it is rescuing a viewing when the current source is dead, serves an unsupported codec, or buffers badly. ## Scope (v1) | | | | ------------- | ------------------------------------------------------------------------------------------------- | | Source types | **Xtream ↔ Xtream only** | | Content | Movies only — series are not offered a source chip | | Environment | **Electron only** — the chip renders nothing in the PWA | | Auto-failover | Opt-in, **off by default** (`Settings.vodAutoFailover`); offered only on the built-in web players | | Pin scope | Per movie (a global portal priority is out of scope) | | Stream probe | HEAD → reachable + latency, sent with the playlist's own playback headers. **No codec probing** | Stalker never reaches the `content` table (it would need a live authenticated `get_ordered_list&search=` per portal), and M3U playlists are stored as a JSON blob whose search path forces `content_type: 'live'`. Both are additive later without changing the contracts — `VodSourceCandidate.portalType` already carries `'xtream' | 'stalker' | 'm3u'` and discovery sits behind a service interface. A probe answer is cached per _request_, not per URL: two playlists can share a stream URL and require different headers, and one of them answering 403 says nothing about the other. `ffprobe`/`ffmpeg` are not dependencies of this app and are not bundled, so `provenance: 'probe'` means reachability and latency only. There is deliberately no feature flag for codec probing: it would gate a code path with no binary behind it. ## The honesty rule This is the part to preserve if anything here is refactored. Every metadata value carries **where it came from**: | provenance | produced by | rendered as | | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------- | | `api` | `get_vod_info` — container, codec, audio, dimensions | plain tag | | `parsed` | regex over the title/filename | tag prefixed `~`, warn colour | | `probe` | HEAD → reachable + latency (retried as a ranged GET when the server answers 405/501, since plenty serve media over GET while refusing HEAD) | `ok` / `fail` status tag | | _absent_ | — | **no tag at all** + a `check` chip | Three rules follow, and each is enforced in code rather than by convention: 1. **A guess never ranks.** `factualOnly()` (`libs/portal/shared/data-access/.../vod-source-metadata.util.ts`) is the only sanctioned accessor for ranking and failover decisions, and `parsed` values are structurally unreachable through it. A filename claiming 4K cannot outrank a source that was actually reached. 2. **Unknown is not "unavailable".** `VodSourceProbeStatus` separates `fail` (contacted and refused) from `unknown` (timed out, blocked by the redirect policy, or no probe capability). A probe returning HTTP status `0` maps to `unknown`; the UI keeps offering a check and never shows the source as dead. 3. **Empty beats wrong.** Quality is derived from pixel _width_, because letterboxed masters are cropped vertically — a 2.39:1 1080p film is 1920×800, and 800 alone is indistinguishable from a 1280×800 encode. With no width, a height is trusted only within 5% of a standard frame height; otherwise no tag is emitted. Below the HD widths the ranges stop working: 960×540 and 1024×576 are two formats inside one 900–1199 range, 800×600 and 800×450 are neither 480p nor each other, and 720 wide is NTSC 480p or PAL 576p depending only on the height. Those formats are therefore matched rather than bucketed, and an unrecognised shape returns nothing rather than a label that would be published as an `api` fact. A known height has to be consistent with the width **on every tier**, ranges included. Cropping only ever _removes_ lines, so a shorter frame is a letterboxed master of that format, while a taller one is a different shape: 640×480 against 640×360 below, and 1440×1080 (anamorphic 1080) or 1600×900 against the 720p range above. All of those get no tag. Bucketing HD widths is otherwise sound — the standard widths really are far apart — but only once the height is allowed to veto the answer. Provenance is per-field and changes over time: at discovery a row has only `parsed` tags, because the `content` table stores no container, codec or audio. Facts arrive when the source is resolved. ## Architecture ``` VOD details page (Xtream) └── VodMultiSourceHostService component-provided, one per open movie ├── VodMultiSourceController session state + failover ranking ├── VodSourceDiscoveryService ──► DB_FIND_TITLE_SOURCES (trigram FTS) ├── VodSourceResolverService ──► foreign playlist creds → get_vod_info │ → constructVodUrl ├── VodSourcePinService ──► DB_GET/SET/CLEAR_VOD_SOURCE_PIN └── StreamProbeService ──► STREAM_PROBE_URL (main process) ``` `VodMultiSourceHostService` is **component-provided, never root-provided**: the controller's "each source is tried at most once" set must die with the movie, or a later film inherits a poisoned failover history. `VodMultiSourceController` is a plain class, not a service, for the same reason — and so its ranking logic is testable without TestBed. ### Ownership | Concern | Location | | -------------------------- | ---------------------------------------------------------------------- | | DTOs, match key | `libs/shared/interfaces/src/lib/vod-source*.ts` | | Pin table | `libs/shared/database/src/lib/vod-source-pins.schema.ts` | | Discovery SQL | `apps/electron-backend/.../operations/title-sources.operations.ts` | | Pin CRUD | `apps/electron-backend/.../operations/vod-source-pin.operations.ts` | | Probe handler | `apps/electron-backend/src/app/events/stream-probe.ts` | | Discovery / resolve / rank | `libs/portal/shared/data-access/src/lib/multi-source/` | | Probe + pin clients | `libs/services/src/lib/{stream-probe,vod-source-pin}.service.ts` | | Row / popover / chip | `libs/ui/components/src/lib/vod-sources/` | | Page wiring | `libs/portal/xtream/feature/src/lib/vod-details/vod-multi-source-*.ts` | ### One picker, two places, two counts The chip on the action row and the chip in the inline player's now-playing bar are the same component, so both are handed the same `matchKind` and the same `vodAutoFailover` value and both write the setting back. A copy that rendered the toggle off while it was on — and did nothing when flipped — would be worse than not offering it. The two numbers around it are deliberately different, because their sentences are: the details-page chip says "Sources N" and counts every copy across all playlists — the total the popover lists, route copy included — while the caption says "also found in N other playlists" and counts distinct **playlists** (`alternativePlaylistCount`). The popover groups a portal's three copies of a film under that one portal, so a badge counting playlists would contradict the "All (N)" chip inside, and a caption counting streams would contradict the grouped list it invites the user to open. (The in-player chip still passes the alternatives count: its sentence is "N other places to go", not "N copies exist".) ### The popover: anchoring and fit The chip opens the popover **above** itself, right edges aligned, through a CDK connected overlay with flexible dimensions. That combination is the whole fit contract: - The overlay's bounding box caps the panel to the space between the chip and the viewport edge (16px margin), and inside the panel only the source LIST scrolls — header, search, filter chips and the auto-failover footer are `flex: none`, so they stay visible however short the panel gets. - The overlay's `minHeight` (280px) exists for the FLIP decision, not for sizing: when less than that remains above the chip, CDK skips the position and the panel opens below instead, tail mirrored. As an inline pane style that minimum would also stretch a two-source panel to 280px, so the pane classes neutralize it visually (`.vod-sources-pop--*`). - The position strategy re-applies itself on window resize, so the cap and the flip both hold at any window proportion without component code. ### The popover: filters The chip row composes with the host search (AND): **All (N)** resets the chip filters and states the total copy count, **Available** keeps only sources whose probe verified them, **HD+** keeps sources whose quality tag reads 1080p or better, and the language select is built from the `EN|`-style prefixes actually present in the raw titles. Two of these encode a decision worth writing down: - "Available" is strict: only `probe.status === 'ok'` passes. An unchecked source must never pass a filter with that name — and because checks are lazy, activating the filter while NO source anywhere has a verdict runs check-all itself rather than filtering against nothing. - "HD+" reads the quality tag whether stated (`api`) or guessed (`parsed`). This is a deliberate, narrow exception to "guesses never drive decisions": the filter is a browse aid the user operates while looking at the `~` markers, not an automatic choice — and hiding a copy whose own title says 1080p would make the filter look broken. Ranking and failover still go through `factualOnly()` and cannot see guesses. When search or filters reduce the list, a muted "X of N" counter appears, and groups with no matching copy disappear entirely. ### The popover: copy rows Expanding "N copies in this playlist" lists EVERY copy of the group — including the one the parent row already shows — as compact `app-vod-source-copy-row`s indented under the parent's text column. The playlist's name and monogram are not repeated: the primary text is the provider's own raw stream title (mono), with the parsed `EN|`/`RU|` language prefix promoted to a chip before it. The tag row shows only values that DIFFER from the parent's copy (identical container/codec are omitted), so what distinguishes a copy is the only thing on the line; the copy identical to the parent shows a muted "same as above" note instead. The fuzzy-match warning and the probe verdict are per-copy claims and always render. Each copy row keeps its own check and play actions — play switches playback to that exact stream and moves the active badge. ### Checks: bounded, remembered "Check all" (and the Available filter's implicit one) fires one task per unchecked source, and each task costs a live `get_vod_info` against a foreign portal plus a HEAD at the stream. The host therefore runs at most **4** checks concurrently (`createCheckQueue` in the vod-details folder); a row flips to "checking" the moment it is asked for — which is also what dedupes a second click while it waits for a slot. Settled verdicts (`ok`/`fail`, never `unknown`) are remembered for 10 minutes in the root-provided `VodSourceProbeCacheService`, keyed by source id — i.e. per movie **and** per source. The per-movie controller dies with its detail page, so without this every navigation away and back would re-contact every foreign portal on the next check-all; with it, a rediscovery seeds untouched rows from the cache and shows "available · 0.3s" again without a request. The cache is in-memory only: a probe verdict is a claim about the present, and persisting it across app launches would let a stale "available" outlive the stream it described. ## Identity Provider ids cannot key a pin — the same film has a different `stream_id` in every portal, which is the problem being solved. `buildVodSourceMatchKey()` produces `tmdb:{id}` when a usable TMDB id exists, otherwise `title:{normalizedBase}:{year}` via the shared `normalizeTitleKeys`. Enrichment adds BOTH identifying fields late, so the same movie can already be pinned under any poorer form of itself: | pinned when | stored under | | ------------------- | --------------------- | | after enrichment | `tmdb:{id}` | | before the TMDB id | `title:{base}:{year}` | | before the year too | `title:{base}:` | `buildVodSourceMatchKeyCandidates` returns all three, most-trusted first. Reading every alias is what keeps a late TMDB id from orphaning an earlier pin. Three key sets, because reading, writing and deleting are different questions (`pinKeysFor` builds all three so they cannot disagree): | set | contents | why | | -------- | ----------------------------------- | ------------------------------------------------ | | `lookup` | every alias above | a pin may sit under any poorer form of the movie | | `write` | `tmdb:` + `title:{base}:{year}` | keys that name exactly ONE film | | `loaded` | the key the pin on screen came from | the only ambiguous row this session may retire | A write stores the decision under **every** key in `write`, and clears whatever stale row is left over. Each half rules out the other's shortcut: - Writing only the top key leaves the movie unfindable under its own poorer identity. A pin set while `tmdb:438631` was known is invisible to the next reopen, which starts out with nothing but a title and a year and asks for `title:dune:2021` — so the preference is ignored until enrichment lands, and permanently if enrichment is off or never answers. Storing it under both keys makes it readable at every stage of the same film's identity, and overwriting the poorer key is also what stops it from still naming the source the user just replaced. - Spreading it across _every_ alias is not the fix either: the yearless form is shared by every remake, so a known-year pin stored there would answer for a different film — pin Dune (2021), open Dune (1984) before its year arrives, and it starts the 2021 source. That form is deliberately absent from `write` for exactly this reason; it stays readable and unwritten. The renderer passes `write[0]` as the pin's own `matchKey` and the rest as `aliasKeys`; `setVodSourcePin` upserts one row per key and retires the leftovers inside the same transaction, so no key list can half-apply. Known limit, inherent to addressing rows by key alone: a write can only touch keys the renderer can _name_. Re-pin a film during a pre-enrichment window and the `tmdb:{id}` row from an earlier, enriched session is not among them, so it survives pointing at the old source — and outranks the title key once the id arrives again. Nothing can enumerate it from the page's side; closing it needs a reverse index from film to key. The window is small in practice (TMDB responses are cached in `tmdb_metadata`, so a revisit usually resolves the id at once) and does not exist at all with enrichment off. A write stores the new key **before** retiring the old rows. The other order destroys the stored preference and can then fail to replace it, leaving nothing persisted while the row still shows the old pin; lookups are most-trusted-first, so a leftover alias never outranks the key just written. The pin a rediscovery reads is applied **immediately**, not after its source lookup returns: holding that snapshot across the await lets it overwrite a pin the user makes in the meantime, leaving the row and the primary Play naming a source the database no longer holds. Applying it first makes the later write simply win. For the same reason a write or an unpin never _deletes_ the yearless alias on spec: that row may hold another remake's preference. The single exception is the row this session actually read, because the user is acting on the pin they can see — and leaving that one would make an unpin come back. The row only changes once the write lands. A pin the database refused is worse than no pin at all — the icon promises the preference will be there next time, and it will not be — so `togglePinnedSource` reports "nothing happened" and the controller is left exactly as it was. ### Rediscovery vs. a new session Two keys, deliberately, because the host has two different questions to answer when enrichment lands: - `vodMultiSourceMovieKey` covers title, year and TMDB id. Enrichment changing any of them **re-runs discovery** — that is how a yearless search gets its year and a `tmdb:`-keyed pin becomes findable. - `vodMultiSourceSessionKey` is `playlistId:contentId` — the film itself. It is what decides whether that rerun is a _refresh_ or a _new session_. A refresh keeps the controller: the source the user switched to stays active (with the facts its resolve produced, rather than the catalog's guesses), the tried set stays burned, the live position stays, and a switch already in flight still commits. Rebuilding there would take the film off the source it is actually streaming, and hand failover a clean slate for sources it has already spent. Only a different film resets — including the tried set, which is what makes failover terminate. A rerun can also legitimately _drop_ the playing row: the year the enrichment supplies makes the year gate reject a copy the yearless search had admitted ("Dune" 1984 while watching the 2021 film). Off the list is right — it is not the same film. Off the screen is not, so `applyDiscoveredSources` keeps it as a row and leaves it active; a caption naming a playlist that is not streaming anything would be a lie about the one thing this feature exists to state. ## What the queries are allowed to miss A source that exists but is never read is indistinguishable, to the user, from one that does not exist — the chip simply does not appear. So: - **The current playlist is excluded in SQL**, not afterwards. It routinely lists a film in several categories, and those rows would otherwise spend the FTS window before a single other playlist was read. - **Duplicates collapse in SQL too**, for the same reason. One playlist can list a film in dozens of categories, and those rows rank identically, so `GROUP BY cat.playlist_id, c.xtream_id` runs before the limit. Collapsing them only in TypeScript afterwards cannot recover the playlists the window never reached. - **Short titles scan on a word boundary, and take no window at all.** The trigram tokenizer cannot index tokens under three characters, so "Up", "It" or "Us" produce an empty `MATCH` and fall back to a scan. A substring scan matches "Titanic" and "The Italian Job" for "It", so the scan asks for the token as a word (`' ' || LOWER(title) || ' ' GLOB '*[^a-z0-9]it[^a-z0-9]*'`) and orders by title length (a match is the title plus decoration: "IT (2017) 1080p"). The FTS path keeps its 60-row window because it ranks by relevance — the best rows are the ones it keeps. A scan cannot rank, so a window there would silently decide which valid sources the user may see, and it would not even buy anything: the GLOB cannot use an index, so SQLite reads every row either way and a `LIMIT` saves transfer, not work. What bounds the scan instead is its predicate: reaching it means NO token cleared the trigram minimum — a one-or-two-character title like "It", but also an all-short multiword one like "I Am" — and EVERY token must then appear as a word. Matching on the first token alone would return most of a large catalog for the confirmation pass to discard, which on the single database worker is real blocking. Like the `LIKE` it replaces it compares ASCII-lowercased text, so a non-ASCII short title is no better and no worse served than before. Both remain necessary-not-sufficient filters: the two-tier normalized confirmation still runs afterwards, so the looser query never admits "Upgrade" for "Up". One row inside the excluded playlist is kept when the caller names it (`keepContentId`): a pin can point at another copy of the film in the playlist being viewed, and dropping that row would leave the preference pointing at nothing. The host therefore reads the pin BEFORE discovery. When that pin is the route's _own_ row, the kept copy and `currentSourceRow()` are the same stream, so `applyDiscoveredSources` drops the duplicate rather than listing it twice. ### Same title, different film The year gate applies to **both** match tiers, not just the year-stripped one. `normalizeTitleKeys` strips bracketed segments wholesale — they usually hold quality and language tags — so "Dune (1984)" and "Dune" normalize to the same string and the exact tier would accept the remake without ever consulting a year, ranked _above_ every fuzzy match. Discovery reads a bracketed year out of the raw title first, and when both sides state a year and they disagree, it is not the same movie. An unknown year still never blocks. The two tiers read different years, though. The **base** tier accepts either form, bracketed or trailing, because it has just stripped a trailing year and that year is the only thing standing between "Dune 1984" and "Dune 2021". The **exact** tier reads the bracketed form ONLY: reaching it means both titles are the same string, so a trailing four digits belong to both, and weighing a number that is part of the NAME against a release year out of metadata rejects the very copy it was meant to confirm — "Blade Runner 2049" against a stated 2017 disappears the moment enrichment lands. Brackets are never part of a name, so "Dune (1984)" is still rejected against 2021 on the exact tier. Which is why the movie's OWN year is read with `releaseTagYear`, not `extractYear`. The latter takes a year from anywhere in the title, which is the right answer where a year is only a search hint that scoring will confirm — and the wrong one here, where the year is part of an identity. "2001: A Space Odyssey" is not a 2001 film: calling it one makes every genuine 1968 copy fail the gate above, so the movie has no alternatives at all, and it moves the pin key the moment enrichment supplies the real year. Only bracketed and trailing forms count. The trailing form stays ambiguous on purpose ("Blade Runner 2049" is a title, not a tag) — that is what the two-tier exact/base match is for. ## Why resolution is lazy The `content` table stores no `container_extension`, and `XtreamUrlService.constructVodUrl` returns `''` without one. A discovered source is therefore **not playable from the database** — every alternative costs one live `get_vod_info` against a foreign playlist's credentials, which can fail offline, on an expired account, or behind Cloudflare. So: rows render instantly from the FTS match with `parsed` provenance, and a URL is resolved only when the user clicks play, pins, or checks. Containers are memoised per `(playlistId, streamId)` for the session, and a container learned earlier is reused if the portal later goes unreachable. Resolution is never fanned out on page load. ## Switching without losing the timecode Every playback host renders `@if (inlinePlayback(); as playback)`, so re-`set()`ing that signal with a new `{streamUrl, startTime}` swaps the source **in place** — the player component, `WebPlayerView` and the engine all survive, and `WebPlayerViewComponent`'s effect rebuilds the source and clears the diagnostic. Three details make the position survive: - The carried position is the **live** one. `handleInlineTimeUpdate` reports to `VodMultiSourceHostService.reportPosition()` _before_ the 15-second persistence throttle, so a switch does not rewind by up to 15 seconds. External players have no `timeupdate` at all, so for them the polled `playback_positions` value IS the live one and is reported directly — seeding it would freeze the resume point where playback started. - It is a single `.set()`, never `null` then set — a null in between would destroy the player subtree and lose the engine. - `playback_positions` is keyed `(playlistId, contentXtreamId, contentType)`, so a switch changes the key. The resolved playback carries the **new** source's `contentInfo`, and that source's row takes over. The position also has to exist _before_ anything plays. Nothing reports a live one until the first `timeupdate`, so a pinned source started straight off the Resume button would resolve at zero and restart the film. The controller is therefore seeded from the persisted position (`seedResumeSeconds`), one-way: once a live position exists it wins, because the stored one lags it by up to the save throttle and applying it would visibly rewind. A resuming engine can emit a `timeupdate` at ~0 before it finishes seeking. `VodDetailsPlaybackService` guards this with a one-shot `resumeSettled` latch — a filter would have broken deliberate seek-backwards. The latch also releases when the target is out of reach: switching a two-hour position into a 90-minute cut means the engine can never report it, and waiting would suppress every save for the rest of the session. `handleInlineTimeUpdate` returns that verdict and the route feeds multi-source the `startTime` it asked for until the engine gets there, so a switch or a failure during the initial seek does not resolve the next source at zero and restart the film. One latch serves both, because two would eventually disagree. ## Failover Only fires when `Settings.vodAutoFailover` is on, and it first awaits a discovery still in flight — a stream can fail faster than SQLite answers, and concluding "nowhere to go" against an empty controller would strand the user on the error screen with alternatives landing a moment later. `stillOwnsScreen()` does that wait and then re-checks the session, because the user can navigate during it and the controller afterwards may belong to a different film; the pinned-Play path takes the same wait, or a persisted pin would lose to worker latency. Ranking (`pickFailoverTarget`): 1. never tried this session — a **hard filter**, not a preference 2. probed reachable; probed failing is penalised 3. not known to have failed recently 4. richer **factual** metadata (via `factualOnly`) 5. exact title match over fuzzy Termination is structural: `triedSourceIds` only ever grows within a session, so an N-source movie fails over at most N−1 times and then shows the honest error screen. Returning to an earlier source by hand does not clear the set. Selection is not an attempt. `setActiveSource` only selects; `markPlaying` also spends the source's turn, and only the three places that really start playback call it — a switch, the route's own Play/Resume, and restoring the playing row after a rediscovery. Discovery selects the route's row the moment the page opens, and a pin or the picker can select an alternative before anything plays; counting those would let a later failure skip a healthy fallback, or call the options exhausted with one untouched. `runFailover` then retires whatever is on screen before picking, so the source that just failed is spent however it got there — one hole per start path would be an infinite ping-pong between two sources. A source that cannot even be resolved is marked tried without becoming active, and failover **continues to the next candidate** rather than giving up — production calls `failover()` only once, on the original failure, so stopping at a dead top-ranked source would strand every healthy one below it. `switchTo` therefore reports which of two things happened: `unresolvable` (marked tried, keep going) or `superseded` (something newer owns the screen, stop). Without that distinction the loop would spin on a superseded target forever, because only the first outcome marks the candidate tried. **A pin is not decoration.** The primary Play action starts from the pinned source when one is set, and the pin outranks every other signal in the ranking above. Loading a pin that only decorated its row would mean "make this the main source" survived a restart as an icon and nothing else. The switch is **always announced** — another source can carry a different dub or cut. The toast offers Undo, and adds a dub warning when `audioDiffersFactually()` is true, which requires **both** sides to state an audio track as fact. Two guesses, or a guess against a fact, stay silent. Web engines only (HTML5/hls.js, Video.js, ArtPlayer). Embedded MPV suppresses shared diagnostics and owns its own error block; external MPV/VLC are fire-and-forget with no error channel back. ## External players and an alternative source A switch goes through the same inline-vs-external fork a normal Play takes, so with MPV or VLC configured the alternative opens in the external player — and that session carries the OTHER playlist's ids. `matchedExternalPlayback` would disown it: the primary button never became Stop, stopping found no session, and another click opened a second player. The page therefore claims a session that matches either the route's own stream or the alternative multi-source says is active (`VodDetailsPlaybackBindings.activeSource`). `ownsContent()` answers that question once, for both consumers: the session matcher AND the playback-position bridge. They cannot be allowed to disagree — a page that shows a Stop button for a session whose progress it discards keeps the resume point at wherever playback began, so a switch an hour later rewinds the whole session. The caption itself appears only while a player is actually running — inline or a matched external session, and not while a playback diagnostic is up. Discovery marks a source active as the page opens, so gating on that alone would have the page claim "Playing from …" before Play was pressed, after the player was closed, and over the error screen for a stream that would not play. Whichever source ends up playing, the "playing" badge follows it: starting the route's own stream (Play, Resume, Restart, or the fallback after a pin does not apply) hands the badge back to the route row, or the picker and caption go on naming an alternative that is no longer running. That hand-back also invalidates a switch still resolving — the user chose the route stream, and an older resolution arriving afterwards would replace what they just asked for. And a source started through the picker or a pin is recorded in Recently Viewed exactly as an ordinary Play is — it is the same film, watched. Stop then has to win over the pin. The primary action consults the pin first — that is what makes "make this the main source" decide where playback starts — but when a session is already running the same button reads Stop, and doing anything other than stopping would launch a second player while the first kept going. ## PWA Discovery, foreign-playlist reads, the pin table and the probe are all main-process. A browser HEAD to an arbitrary IPTV host is CORS-blocked, and `no-cors` yields an opaque response where 200, 403 and 404 are indistinguishable — so the PWA cannot answer these questions honestly rather than merely lacking a convenience. Every entry point is gated on a bridge `typeof` check (`isAvailable`), matching `CatalogTitleMatchService`. In the PWA the chip renders nothing and the auto-failover setting is hidden. ## Resuming a pinned copy Playback positions are keyed by (playlist, stream), so a pinned alternative carries its own. `playPinned` looks that position up and applies it — and applies **zero** when the lookup comes back empty, because the controller is still holding the ROUTE copy's position at that moment. Carrying it across would drop the user into the middle of a film they never started here, and the first save would write that timecode under the pinned source's key. When no lookup function is supplied at all, nothing is applied: "never watched" was never established, so there is nothing to correct. ## What the primary button describes Two position signals, not one. `vodPlaybackPosition` is the LAST position seen — whichever copy produced it — and feeds the progress bar and the switch handoff. `routePlaybackPosition` is the route copy's own row, and everything that acts on the route's stream reads that: Resume, its label, its timecode. Collapsing them lets an alternative's progress resume the route copy at a timecode nobody reached in it. Route reuse (the Similar rail) clears both, so the button cannot describe the previous movie while the new lookup is still in flight, and every route start — including the primary button's fall-through past an unresolvable pin — goes through the route's own wrappers, which replace whatever timecode an alternative left in the controller. While the pinned copy is the one playing, its live position wins over the row that was stored before this session started. A pin means the button plays a copy the page did not load a position for. A watched-through copy resolves to zero rather than its stored seconds, through the same `isResumablePosition` rule the label uses — otherwise the button reads Play and then seeks back to where the film ended. Restart follows the pin for the same reason: with Resume honouring a pinned copy, a Restart that started the route copy would silently switch the user's playlist. `createPrimaryActionPosition` therefore looks that copy's row up and lets it govern the label, the timecode and the Restart affordance — including when the lookup comes back empty, because "never watched" is an answer: the button must read Play, not `Resume 42:18` on a stream that starts at zero. A pin on the route's own row changes nothing; the loaded position already IS that copy's. ## Provider codec metadata `info.video` / `info.audio` come back in two shapes: the declared string array (`['H.264']`, which the mock server and many panels send) and the ffprobe object carrying `codec_name`/`width`/`height`. `readStreamInfo` accepts both — reading only the object silently lost the codec on every array response. That codec is a **display** fact and nothing more. The "dub may differ" warning reads `audioLanguage`, which comes from the track's language tag (`info.audio.tags.language`, or `language` on panels that hoist it) and never from `audio`. A codec cannot answer the question the warning asks: AAC and AC3 routinely carry the same dub, and two AC3 tracks can carry different ones, so comparing codecs fired on every identical-language re-encode and stayed silent on the dub changes it exists for. Wrong in both directions is worse than absent, because a warning people learn to ignore is not a warning. Few panels tag a language at all, so in practice it is usually silent — which is the honest state, and the same one the rest of this feature takes when it does not know. Switching sources through `startResolvedPlayback` closes the external session it LAUNCHED first — tracked separately from the controller's active source, which a switch has already moved to the destination by then. It REPLACES what is playing — with MPV or VLC and instance reuse off, the backend would otherwise spawn a second detached player, leaving both sources running and Stop owning only the newer one. ## Short titles and Unicode The title index folds diacritics. `content_title_fts` is created with `tokenize='trigram remove_diacritics 1'`, because matching compares NORMALIZED titles ("Amélie" → "amelie") against an index built from the raw one — without folding, every accented title was invisible to the FTS path, and two identical `Amélie` entries produced no candidates at all. The tokenizer is fixed at CREATE time, so existing databases are recreated and rebuilt once behind `migration:content-title-fts-remove-diacritics:v1`. `remove_diacritics` needs SQLite 3.45+. The migration probes support on a temp table first and does nothing when the runtime rejects it, leaving the working index in place — and does NOT record itself as done, so a later app version shipping a newer SQLite upgrades then. (better-sqlite3 currently bundles 3.53, so the fallback is defensive rather than a path anyone is on.) The completed marker is not taken as proof. `createTables` declares this table too, with the plain tokenizer, and `CREATE TABLE IF NOT EXISTS` would recreate it unfolded if it ever went missing after the marker was written — leaving two sources of truth for one tokenizer. The migration therefore reads the live table's own DDL out of `sqlite_master` and rebuilds unless it really folds. A degraded index is otherwise invisible: discovery simply stops finding "Pokémon" for "pokemon", with nothing to indicate it should have. **Case folding for non-ASCII, on the FTS tier, is still not possible.** `LOWER()` and the trigram tokenizer both fold ASCII only, so a Cyrillic title stored with different capitalisation in two playlists ("ОН" vs "Он") cannot be folded by the indexed path. Closing that needs a stored normalized-title column, which is deliberately out of scope here. The **scan** tier does fold it, because GLOB character classes are _not_ ASCII-only — `patternCompare` reads them as UTF-8 code points, and `'Он' GLOB '*[Оо][Нн]*'` is true. `caseInsensitiveGlobPattern` therefore folds the case in JavaScript, where Unicode case mapping is real, and hands SQLite one class per character. A letter can have more lowercase spellings than case mapping reaches from any one of them: Greek `Σ` lowercases to `σ`, but a word-final sigma is written `ς` and is equally a lowercase of it, and neither `Σ` nor `σ` arrives at `ς`. Each class is therefore built from a **fold group** — every character sharing an uppercase form — so every spelling reaches every other one. A request for `ΑΣ` finds a stored `Ας`, which the earlier one-way reach (`ς` found `Σ` and `σ`, but never the reverse) did not: uppercase is just as typeable as lowercase, so "`ς` only occurs word-finally" never justified the asymmetry. `CASE_FOLD_GROUPS` is derived by scanning the cased ranges at module load, the same way `ACCENTED_BY_BASE` is, rather than tabulating pairs by hand — so it generalises past sigma on its own: dotless `ı` folds with `i`, the long `ſ` with `s`, and the historic Cyrillic letterforms with `В Д О С Т Ъ Ѣ`. Only the groups a per-character fold would miss are kept, 24 of 767, since the rest are just {upper, lower} and add nothing. Widening a class only ever costs candidate rows: the scan is a necessary-not-sufficient filter and `normalizeTitleKeys` is what confirms a match. **Admitting a candidate is only half of it.** A class that admits a row the confirmation then rejects finds nothing, so sigma has to be folded on both tiers. `normalizeTitleKeys` therefore rewrites `ς` to `σ` after lowercasing. This is not symmetry for its own sake: `toLowerCase` picks the form by position, so `"ΑΣ"` arrives as `"ας"` while an already-lowercase `"ασ"` stays medial, and the same word reaches the comparison spelled two ways. Both SQL tiers were already folding them together — SQLite's trigram tokenizer does full Unicode folding natively (unlike `LOWER()`, which is ASCII-only), and the scan's GLOB classes now do it in JavaScript. The confirmation was the only tier that did not, which made this a **pre-existing gap on the FTS path too**, not just on the scan: a stored `"ο αρχοντασ"` was returned as a candidate for `"ο αρχοντας"` and then discarded. Folding to the medial form is what Unicode case folding does. It returns `null` — leaving the substring tests as the whole answer — for a token holding a GLOB metacharacter (SQLite GLOB has no escape character, so an unescaped `*` would become a wildcard matching every row) or a case mapping that changes length (`ß` uppercases to `SS`, `İ` lowercases to two code points). Neither has a single-character class that means the same thing, and a wrong pattern is worse than an absent one. The ASCII/Unicode branch is decided from the RAW token, not the normalized one: normalization folds diacritics, so "Ça" arrives as "ca" and looks like plain ASCII while the stored title still reads "Ça". ASCII tokens keep the word-boundary GLOB (what stops "it" matching "Titanic"). The non-ASCII branch keeps both substring tests alongside the folded class, because the class is built from the raw token and cannot match across a diacritic difference, which the folded-token test does. It has no word boundary — `[^a-z0-9]` would treat every Cyrillic letter as a separator — so it is looser, and the normalized confirmation afterwards is what makes looser safe. ## Claims about the present `isActive` means "the source a switch or Play would use" — selection, not playback. `pinnedSourceAwaitingPlay` therefore takes `playbackLive` as well: a pinned row stays selected after its player is closed, and skipping the pin on selection alone would send the next Play to the route copy. Discovery sets it the moment the page opens, and it survives closing the player — so it cannot, on its own, back a statement in the present tense. `VodDetailsRouteComponent.playbackLive` is that statement. Inline, it needs a `timeupdate`: `inlinePlayback()` is only the REQUEST to play, non-null while the engine is still opening the stream and still non-null after it fails, while a timeupdate is the engine reporting frames. External, it needs the session past `launching`. Every path that mounts a stream clears the latch first — Play, Restart, and a source switch, which puts a DIFFERENT stream into the same host and so cannot inherit the old one's evidence. Two things read it, and they must agree: the "Playing from" caption, and the source row's badge — which reads `Current` when a source is merely selected and `Playing` once one really is. ## Where the route's code lives `VodDetailsRouteComponent` is a thin host. The multi-source concerns it grew live in `VodDetailsMultiSourceUiService` (component-provided): the `playbackLive` evidence, the caption, the primary button's position, the source actions, and the failover toast. The "Similar" rail and offline downloads sit in their own component-provided services beside it. ## Backup `playPinnedSource` reports `played` / `superseded` / `unavailable`, and only `unavailable` may fall through to the route source. Collapsing the first two meant a double-click on Play — where the second attempt supersedes the first — had the losing attempt conclude "no usable pin" and start the route stream over the playback the winning one had just begun. Same distinction as `runFailover`'s, for the same reason. A pin is written under every key naming its film, and its stale aliases retired, in ONE transaction (`setVodSourcePin(db, pin, retireKeys, aliasKeys)`). Split in two there is no honest outcome for a half-failure: a surviving alias is read before the canonical key on the next open, so reporting success starts the source the user just replaced — while reporting failure leaves the canonical row durable and the UI showing a pin that is no longer the stored one. A call with no usable key reports failure rather than claiming a preference it never wrote. Pins ride along with playlist backup, under the playlist they point at, as the optional `sourcePins` collection. See `docs/architecture/playlist-backup-restore.md` for the remapping and sanitizing rules — the short version is that `matchKey` names the film and survives as-is, while the playlist id becomes the imported copy's. Both restore routes use the same atomic replacement: the direct backup restore and the parked replay after a fresh Xtream import call `VodSourcePinService.replaceForPlaylist`, whose worker operation clears the playlist's pins and inserts the complete restored set in one transaction. For direct restore, that preserves the existing pins if an insert fails. A fresh import has no pre-existing pins to lose; there it prevents a partially applied prefix from being visible before the parked state is retried. The parked state is consumed only after that atomic replacement succeeds, and its removal is verified (with an empty tombstone as the safe fallback when storage removal fails). Consumption compares the current parked snapshot with the one that was applied. Store-owned replay and direct backup restore share a playlist-scoped FIFO coordinator and consume a revision captured for the content generation they restored. Duplicate consumers of that revision coalesce, while a newer revision remains parked for its own post-import consumer; an older asynchronous replacement therefore cannot clear or finish after a newer one. Parking is verified before an import can report success, and whole backup imports are serialized as well. Either restore path reports a failed import instead of claiming success when consumption cannot be confirmed. Fresh-import initialization stays blocked and retryable on either failure. Cached content is not exposed while parked state exists: a complete active initialization must restore and retire the snapshot before the catalog opens, because a scope-limited offline cache may not contain every identity referenced by the backup. Route bootstrap and Settings import completion reconcile that gate before content can be edited. The active content route also stays unmounted while replay is pending, and the import overlay follows the full initialization session (including cache-only retries), not only remote-download events. ## Which engines can fail over Only the built-in web players (HTML5, Video.js, ArtPlayer) raise the playback diagnostic that reaches `onPlaybackFailed()`. `WebPlayerViewComponent` suppresses it for Embedded MPV, and external MPV/VLC never mount that component at all — a stream that dies there is invisible to the app. So the toggle is hidden, not merely inert, on those engines: in `Settings > Playback` (`reportsPlaybackFailures()` gating the row) and in the sources menu (`autoFailoverSupported`). Leaving it visible would let a user switch on a feature that can never fire. The stored preference is untouched by the change — switching back to a web player restores whatever was set.