Kordant/tasks/android-production/11-background-sync.md

11. Background Sync & WorkManager Optimization

meta: id: android-production-11 feature: android-production priority: P2 depends_on: [] tags: [performance, background, production]

objective:

• Optimize background sync using WorkManager to keep data fresh without excessive battery drain

deliverables:

• WorkManager periodic sync workers
• Battery-efficient sync strategy
• Constraint-based scheduling
• Sync status indicators

steps:

1. Audit existing sync:
   • Review android/app/.../data/sync/SyncManager.kt
   • Review OfflineWorker.kt
   • Identify sync frequency and triggers
2. Optimize sync workers:
   • Use PeriodicWorkRequest for regular sync (15 min minimum)
   • Use OneTimeWorkRequest for immediate sync
   • Set constraints: requires network, battery not low
   • Use expedited work for urgent syncs
3. Implement battery-efficient sync:
   • Batch network requests
   • Use delta sync (only changed data)
   • Respect doze mode and app standby
   • Use JobScheduler for API 21-22 (WorkManager uses internally)
4. Add sync types:
   • Alert sync: high priority, frequent
   • Exposure sync: medium priority
   • Spam database update: low priority, daily
   • Watchlist sync: on change
5. Add user controls:
   • Settings toggle for background sync
   • Sync frequency preference (if applicable)
   • Manual sync button in settings
   • Last sync timestamp display
6. Handle failures:
   • Exponential backoff for failed syncs
   • Max retry limit
   • Alert user after repeated failures
   • Queue syncs for when online
7. Add tests:
   • Test worker execution
   • Test constraint handling
   • Test battery impact

tests:

• Unit: Test worker logic
• Integration: Test WorkManager scheduling
• Battery: Verify minimal battery impact

acceptance_criteria:

• WorkManager configured for periodic sync
• Sync constraints: network available, battery not low
• Delta sync reducing data transfer
• Background sync respects doze mode
• User can enable/disable background sync
• Manual sync button in settings
• Last sync timestamp visible
• Failed syncs retry with exponential backoff
• Battery impact <5% per day from background sync
• Unit tests for all worker classes

validation:

• Enable background sync → workers scheduled
• Turn on airplane mode → sync deferred
• Disable battery saver → sync resumes
• Check battery settings → Kordant background usage minimal
• Trigger manual sync → data updates immediately

notes:

• WorkManager is already included (libs.work.runtime.ktx)
• Minimum periodic work interval is 15 minutes
• Android 12+ has stricter background restrictions
• Use Foreground Service for urgent syncs if needed