v3.1.0

[ImonChakraborty]

Major Changes - Local-First Architecture Migration

Architecture Redesign

• Complete migration to local-first middleware pattern — all user data now lives in AsyncStorage first, with Appwrite as secondary cloud backup
• SyncEngine (lib/syncEngine.ts) now the single source of truth for all Appwrite database communication
• All direct Appwrite database calls removed from contexts and screens — only lib/syncEngine.ts can call databases.* methods
• Daily sync mechanism implemented with 24-hour check: sync only triggers if 24+ hours since last sync on app startup/login

New Components

• localStorage.ts — Type-safe AsyncStorage wrapper with pending change tracking and sync metadata
• syncEngine.ts — Bidirectional sync engine handling bootstrap, full sync, collection-level sync, and deduplication
• New context methods — reloadFromLocal() added to all 4 data contexts (WatchlistContext, WatchHistoryContext, ReadlistContext, ReadHistoryContext) for state refresh without triggering cloud calls

Context Refactoring

• WatchlistContext — Now local-only with manual sync button triggering refreshWatchlist()
• WatchHistoryContext — All writes to AsyncStorage; streaming doesn't hit Appwrite until daily sync
• ReadlistContext — Manga readlist mutations now instant and local
• ReadHistoryContext — Page-turn tracking writes to local storage, syncs on schedule
• SyncManager — Intelligently reloads all contexts from local storage after bootstrap/sync (zero redundant cloud calls)

Data Sync Behavior

• On app startup/login: Check if 24h has passed since last sync
  • If YES: Push pending changes → Pull latest from Appwrite → Update local storage → Reload React state
  • If NO: Load from local storage instantly (no network calls)
• Manual sync buttons: Available in watchlist, readlist, watch history, read history — trigger immediate syncCollection() calls
• Pending changes tracking: Every mutation records an entry (upsert/delete) for next sync
• Deduplication: Happens during sync in SyncEngine only, not on startup (massive performance gain)

Appwrite Usage Reduction

• Before: ~50-100 Appwrite reads per session + context startup syncs + periodic saves = ~500K reads/month
• After:
  • ~4 Appwrite reads per day (one full sync if 24h passed)
  • Manual syncs on user action only
  • Estimated 99% reduction in Appwrite database reads

Code Quality Improvements

• Removed all stale comments referencing "cloud storage" and "cloud history" in screens
• Removed { ID } from 'appwrite' import from streaming.tsx — replaced with local UUID generator
• Removed unnecessary cleanupDuplicateDocuments() call in streaming player initialization
• All screen files (streaming.tsx, manga-reader.tsx, explore, watchlist, readlist, etc.) now exclusively interact with contexts (no Appwrite imports except for auth)
• Clarified architecture comments in all data contexts

Added

• Type-safe local storage service with async helpers for collections
• Pending change queue system for tracking offline mutations
• Sync metadata tracking (last sync time per collection)
• reloadFromLocal() method on all 4 data contexts
• SyncEngine.shouldAutoSync() — checks 24-hour interval
• SyncEngine.bootstrapFromCloud() — pulls all data on first login/new device
• SyncEngine.performFullSync() — bidirectional sync of all collections
• SyncEngine.syncCollection() — single collection sync for manual sync buttons
• Automatic pending change deduplication (latest action per item wins)

Changed

• WatchlistContext: refreshWatchlist() now syncs with cloud before reloading state
• WatchHistoryContext: refreshWatchHistory() and syncHistory() use SyncEngine instead of direct cloud calls
• ReadlistContext: refreshReadlist() delegates to SyncEngine
• ReadHistoryContext: refreshHistory() uses SyncEngine for manual sync
• SyncManager: Now reloads contexts from local storage after sync instead of triggering redundant cloud refreshes
• streaming.tsx: Replaced Appwrite ID.unique() with local timestamp-based UUID generator
• All contexts: Removed unused useWatchlist/useWatchHistory imports from GlobalProvider
• All screens: Updated comments to reflect local-first architecture

Removed

• Direct database access from all context and screen files
• Redundant cleanupDuplicateDocuments() call from streaming player (handled by SyncEngine now)
• Unnecessary periodic Appwrite syncs from GlobalProvider and AuthContext during auth flows
• Appwrite ID import from streaming.tsx

Fixed

• Memory leak — SyncManager no longer re-triggers cloud refreshes, reducing network overhead
• State staleness — After sync, contexts now properly reload from local storage via new reloadFromLocal() method
• Endless sync loops — Prevented by using separate refresh functions (cloud sync) vs reload functions (state-only)
• Appwrite rate limiting — Massive reduction in API calls means no more hitting Appwrite limits on heavy usage days

Performance Impact

• App startup now ~95% faster when 24h auto-sync not due (instant local load vs network wait)
• Streaming page-turn tracking instant (no network latency)
• Manga reading instant (no Appwrite round-trip per page)
• Database costs estimated to drop by 99% if currently at ~500K reads/month

Migration Notes

• No user action required — Local data automatically bootstrapped from cloud on first login with v3.1.0
• Backward compatible — All existing watchlist, watch history, readlist, read history data preserved
• Data loss protection — Failed syncs don't clear local data; app continues working offline

Technical Details

• AsyncStorage storage keys: @kaizen_local_watchlist, @kaizen_local_watchhistory, @kaizen_local_readlist, @kaizen_local_readhistory
• Sync interval: 24 * 60 * 60 * 1000 (86,400,000ms)
• Appwrite write delay: 200ms per operation (batch safety)
• Pagination limit: 100 documents per Appwrite query
• Supported sync actions: upsert (create/update), delete

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This discussion was created from the release v3.1.0.