ChooJeongHo/claude-android-skill

Android Clean Architecture & Offline-First Enforcer

Analyze or implement $ARGUMENTS with strict enforcement of this project's architectural rules.

Layer Rules (Non-Negotiable)

Presentation → Domain (UseCase/Repository interface) only
Data → Domain interfaces only
Core → available everywhere
FORBIDDEN: Presentation → Data (direct DAO/API access)
FORBIDDEN: Domain → Android framework (except Paging)

Clean Architecture Checklist

UseCase

• [ ] One public operator fun invoke() only
• [ ] Delegates to exactly one repository method (no business logic in ViewModel)
• [ ] Returns Flow<T> or suspend result — never raw lists
• [ ] No Android imports (except androidx.paging)

Repository Interface (Domain layer)

• [ ] ISP applied: split by domain (Favorite, Watchlist, Search, etc.)
• [ ] Methods return domain models only — no DTOs, no Room entities
• [ ] Suspend functions for mutations, Flow for observations

Repository Implementation (Data layer)

• [ ] Maps DTO/Entity → domain model at the data boundary
• [ ] Room queries use ORDER BY for sorting (not sortedBy in ViewModel)
• [ ] Detekt LongMethod limit: extract helpers if method > 60 lines

ViewModel

• [ ] Exposes StateFlow<UiState> (sealed class: Loading/Success/Error)
• [ ] Uses Channel.CONFLATED + receiveAsFlow() for one-shot events (Snackbar)
• [ ] No direct DAO/Retrofit calls — only UseCase invocations
• [ ] SavedStateHandle for arguments surviving process death
• [ ] Mutex.tryLock() for duplicate call prevention

Offline-First Pattern (RemoteMediator)

Use this pattern only for HomeFragment tabs (NowPlaying, Popular):

Network available:  API → RemoteMediator → Room → PagingSource → UI
Network absent:     Room cache → PagingSource → UI (1h expiry via RemoteKeyEntity.lastUpdated)

Rules:

• [ ] Room DB is Single Source of Truth — never emit API response directly to UI
• [ ] RemoteKeyEntity.lastUpdated checked before REFRESH (skip if < 1h old)
• [ ] PREPEND always returns MediatorResult.Success(endOfPaginationReached = true)
• [ ] DB writes inside withTransaction (or @Transaction on DAO abstract class)

Search uses network-only PagingSource (no Room cache) — this is intentional.

This Project's Patterns

UI State Observation

// CORRECT: single repeatOnLifecycle block, parallel launches
viewLifecycleOwner.lifecycleScope.launch {
    repeatOnLifecycle(Lifecycle.State.STARTED) {
        launch { viewModel.uiState.collect { ... } }
        launch { viewModel.snackbarEvent.collect { ... } }
    }
}

Error Handling

// Use launchWithErrorHandler from core/util/CoroutineExt.kt
viewModelScope.launchWithErrorHandler(snackbarChannel) {
    _uiState.value = UseCase()
}

Navigation

// Safe Args always — no manual bundle.putInt
val action = FragmentDirections.actionToDetail(movieId = id)
findNavController().navigate(action)

Output Format

## Architecture Review: [Target]

### Violations Found
- **[CRITICAL/WARNING]** (file:line): Rule violated → Correct approach

### Compliance Summary
| Layer | Status | Notes |
|-------|--------|-------|
| Presentation | ✅/⚠️/❌ | ... |
| Domain | ✅/⚠️/❌ | ... |
| Data | ✅/⚠️/❌ | ... |

### Offline-First Assessment
[Is the feature properly cache-backed or correctly network-only?]

### Recommended Changes
[Concrete file edits with before/after code snippets]