iptvnator/docs/architecture/playlist-backup-restore.md

Playlist Backup/Restore Architecture

This document describes the versioned playlist backup/restore flow used by the settings screen.

Entry Points

• UI: apps/web/src/app/settings/settings-backup-section.component.ts (embedded in settings.component.html), with the file read/handoff in apps/web/src/app/settings/settings-backup.facade.ts
• Backup service: libs/services/src/lib/playlist-backup.service.ts
• Manifest types: libs/shared/interfaces/src/lib/playlist-backup.interface.ts
• Xtream pending restore storage: libs/services/src/lib/xtream-pending-restore.service.ts

Manifest Contract

Backups are versioned JSON manifests, not raw Playlist[] dumps and not SQLite database snapshots.

Top-level shape:

• kind: "iptvnator-playlist-backup"
• version: 1
• exportedAt
• includeSecrets
• settings?.epgUrls
• playlists[]

The manifest is portable across machines because it stores playlist definitions and portable user state, while excluding cache-only database content.

Export Scope

M3U

M3U backups are self-contained.

• Always export canonical rawM3u from PlaylistsService.getRawPlaylistById()
• Preserve source metadata when available:
  • original source kind: url, file, or text
  • original URL
  • userAgent, referrer, origin
  • filePathHint for provenance only
• Export playlist-scoped user state:
  • favorites by channel URL
  • recently viewed M3U items
  • hidden group titles

The embedded raw text is the canonical restore artifact. The internal parsed playlist object graph is not the backup format.

Xtream

Xtream backups export only connection metadata plus portable user state.

• Connection metadata:
  • serverUrl
  • username
  • password
• User state:
  • hidden categories by { categoryType, xtreamId }
  • favorites by { contentType, xtreamId, addedAt?, position? }
  • recently viewed by { contentType, xtreamId, viewedAt }
  • playback positions as PlaybackPositionData[]
  • optional VOD source pins by { matchKey, contentId, updatedAt? }

An imported Xtream archive can wait for its catalog to download. Export reads that pending snapshot before consulting the catalog: its hidden categories, favorites, history, and positions are authoritative, including empty lists. Pending pins are authoritative when present; an absent sourcePins field keeps the existing store's pins when that store is available, or stays absent when it is unavailable. Re-export neither applies nor consumes the pending snapshot, so it also works before the portal has been opened and in browser runtimes. Parental category locks still come from the current lock store.

A failed pending-storage or playback-position read fails export. An unreadable collection must never be serialized as a successful empty collection.

Explicitly excluded:

• cached categories/content rows
• import-status flags and other app-state cache markers
• downloads

Stalker

Stalker backups export connection metadata plus playlist-scoped favorites/recent state.

• Exported connection fields:
  • portalUrl
  • macAddress
  • isFullStalkerPortal
  • username
  • password
  • userAgent
  • referrer
  • origin
  • serial/device/signature fields when present
• Exported user state:
  • favorites snapshots
  • recently viewed snapshots

Explicitly excluded — session state, as opposed to the connection definition:

• stalkerToken
• stalkerSessionIdentity (the fingerprint the token was negotiated for)
• stalkerWatchdogTimeout / stalkerTimeslot (the profile-advertised cadence)
• stalkerAccountInfo
• playback positions in v1

App Settings

Only EPG source URLs are backed up at the app-settings level.

• Exported: settings.epgUrls
• Excluded: cached EPG database content

Import Flow

The settings backup facade (settings-backup.facade.ts, driven by settings-backup-section.component.ts) reads the file (file.text()) and hands its contents to PlaylistBackupService.importBackup().

The service:

1. Validates the manifest kind/version before any writes.
2. Rejects legacy raw Playlist[] JSON blobs.
3. Builds stable source fingerprints for merge-vs-create decisions.
4. Upserts playlists into app playlist storage.
5. Restores provider-specific user state.

Fingerprint rules:

• M3U URL playlists: normalized URL
• M3U without URL: hash of canonical rawM3u
• Xtream: normalized serverUrl + username
• Stalker: normalized portalUrl + macAddress

If a fingerprint matches an existing playlist:

• keep the existing playlist ID
• update mutable metadata from the backup
• replace playlist-scoped state with the backup payload

If no fingerprint matches:

• create a new playlist
• reuse exportedId only when it is unused
• otherwise generate a new UUID

Xtream Restore Contract

Xtream restore is type-aware end to end. The app no longer stores plain xtream_id[] arrays for refresh/import restore because IDs can collide across live, movie, and series.

Runtime contract:

• shared shape: XtreamPendingRestoreState
• persisted in local storage by playlist ID
• consumed by:
  • Xtream refresh actions
  • settings backup import
  • Xtream content initialization

Restore state originates from untrusted sources (user-supplied backup files, stale localStorage entries), so every read and write goes through normalizeXtreamPendingRestoreState (libs/shared/interfaces). Entries in hiddenCategories, favorites, and recentlyViewed without a usable numeric xtreamId are dropped rather than restored: backups exported by builds affected by issue #1017 contain ID-less hidden-category entries, and matching them against category rows would otherwise degrade to a type-only comparison that hides every category of that type. Category rows themselves cross the DB worker IPC boundary in the snake_case wire shape declared by XCategoryFromDb/XtreamCategoryFromDb; the category operations project their Drizzle rows explicitly to keep that contract true.

Replacing the playlist's pins deletes by playlist and writes the replacements in one transaction. It does not use the capped keyed-clear operation, which could leave surplus pins behind. Any replacement failure fails the entry and retains the pending snapshot for retry.

sourcePins (VOD multi-source) is the one optional collection, and the normalizer preserves that: an absent field stays absent rather than becoming [], because restore treats a PRESENT collection as authoritative and clears the playlist's existing pins before applying it. Materializing an empty array would turn "this archive predates pins" into "this archive says there are none": archives written before multi-source existed simply do not have it, so its absence is age rather than damage and only a wrong type is rejected. A pin is carried under the playlist it points AT — exporting it anywhere else would restore a preference for a portal the archive never contained. Its matchKey identifies the film rather than the portal, so it survives untouched; only the playlist id is remapped to the imported copy. Pins whose match key or content id is unusable are dropped, since writing one would occupy the unique key of a film it does not describe.

Electron restore behavior:

1. Category import reads pending hidden-category state while saving categories.
2. After content import, favorites/recent state is restored by typed { contentType, xtreamId } matching.
3. Playback positions are replaced for the destination playlist in one SQLite transaction through DB_REPLACE_ALL_PLAYBACK_POSITIONS. Empty means clear; a failed insert rolls back the deletion and all earlier inserts.
4. VOD source pins are re-applied against the IMPORTED playlist id.

For existing Xtream playlists with a fully populated offline cache, backup import applies the restore immediately. Otherwise the typed restore payload is left pending until the next Xtream initialization/import. Both paths use strict playback-position replacement: unavailable storage, rejected IPC, or an unsuccessful response fail the restore and leave the pending snapshot intact. Atomic restore support is checked separately from the ordinary Xtream SQLite capability gate. An older preload missing the replacement method keeps using SQLite for playback and backup export. Import parks the snapshot first, then rejects unsupported atomic restore before checking catalog completeness or writing category visibility, collections, positions, or pins. Deferred restore performs the same preflight before applying user state. The retained snapshot can be retried once atomic replacement becomes available. Ordinary playback keeps its existing capability checks and best-effort persistence API. The whole restore is not one database transaction; already applied categories/favorites/history can remain after a later failure, but the snapshot remains available to retry the complete restore. It is consumed only after every restore step succeeds.

Current UX

The settings page now exports/imports “playlist backups” instead of the old raw JSON application dump.

• Export filename: iptvnator-playlist-backup-YYYY-MM-DD.json
• Import summary reports:
  • imported
  • merged
  • skipped
  • failed