# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

**⚠️ Important:** This is the KMM mobile client repository. For full-stack documentation covering both the mobile app and backend API, see the root CLAUDE.md at `../CLAUDE.md`.

## Important Guidelines

**⚠️ DO NOT auto-commit code changes.** Always ask the user before committing. Only create commits when the user explicitly requests it with commands like "commit this work" or "create a commit".

## Project Overview

MyCrib is a Kotlin Multiplatform Mobile (KMM) property management application with shared business logic and platform-specific UI implementations. The backend is a Django REST Framework API (located in the sibling `myCribAPI` directory).

**Tech Stack:**
- **Shared (Kotlin)**: Compose Multiplatform for Android, networking layer, ViewModels, models
- **iOS**: SwiftUI with Kotlin shared layer integration via SKIE
- **Backend**: Django REST Framework (separate repository at `../myCribAPI`)

## Build Commands

### Android
```bash
# Build debug APK
./gradlew :composeApp:assembleDebug

# Build release APK
./gradlew :composeApp:assembleRelease

# Run on connected device/emulator
./gradlew :composeApp:installDebug
```

### iOS
```bash
# Build from command line (use Xcode for best experience)
xcodebuild -project iosApp/iosApp.xcodeproj -scheme iosApp -sdk iphonesimulator -destination 'platform=iOS Simulator,name=iPhone 17' build

# Or open in Xcode
open iosApp/iosApp.xcodeproj
```

### Desktop (JVM)
```bash
./gradlew :composeApp:run
```

### Web
```bash
# Wasm target (modern browsers)
./gradlew :composeApp:wasmJsBrowserDevelopmentRun

# JS target (older browser support)
./gradlew :composeApp:jsBrowserDevelopmentRun
```

## Architecture

### Shared Kotlin Layer (`composeApp/src/commonMain/kotlin/com/example/mycrib/`)

**Core Components:**

1. **APILayer** (`network/APILayer.kt`)
   - **Single entry point for all API calls**
   - Manages caching via DataCache
   - Handles automatic cache updates on mutations (create/update/delete)
   - Pattern: Cache-first reads with optional `forceRefresh` parameter
   - Returns `ApiResult<T>` (Success/Error/Loading states)

2. **DataCache** (`cache/DataCache.kt`)
   - In-memory cache for lookup data (residence types, task categories, priorities, statuses, etc.)
   - Must be initialized via `APILayer.initializeLookups()` after login
   - Stores `MutableState` objects that UI can observe directly
   - Cleared on logout

3. **TokenStorage** (`storage/TokenStorage.kt`)
   - Platform-specific secure token storage
   - Android: EncryptedSharedPreferences
   - iOS: Keychain
   - All API calls automatically include token from TokenStorage

4. **ViewModels** (`viewmodel/`)
   - Shared ViewModels expose StateFlow for UI observation
   - Pattern: ViewModel calls APILayer → APILayer manages cache + network → ViewModel emits ApiResult states
   - ViewModels: `ResidenceViewModel`, `TaskViewModel`, `AuthViewModel`, `ContractorViewModel`, etc.

5. **Navigation** (`navigation/`)
   - Type-safe navigation using kotlinx.serialization
   - Routes defined as `@Serializable` data classes
   - Shared between Android Compose Navigation

**Data Flow:**
```
UI → ViewModel → APILayer → (Cache Check) → Network API → Update Cache → Return to ViewModel → UI observes StateFlow
```

### iOS Layer (`iosApp/iosApp/`)

**Integration Pattern:**
- SwiftUI views wrap Kotlin ViewModels via `@StateObject`
- iOS-specific ViewModels (Swift) wrap shared Kotlin ViewModels
- Pattern: `@Published var data` in Swift observes Kotlin `StateFlow` via async iteration
- Navigation uses SwiftUI `NavigationStack` with sheets for modals

**Key iOS Files:**
- `MainTabView.swift`: Tab-based navigation
- `*ViewModel.swift` (Swift): Wraps shared Kotlin ViewModels, exposes `@Published` properties
- `*View.swift`: SwiftUI screens
- Directory structure mirrors feature organization (Residence/, Task/, Contractor/, etc.)

**iOS ↔ Kotlin Bridge:**
```swift
// Swift ViewModel wraps Kotlin ViewModel
@StateObject private var viewModel = ResidenceViewModel() // Swift wrapper
// Inside: let sharedViewModel: ComposeApp.ResidenceViewModel // Kotlin

// Observe Kotlin StateFlow
Task {
    for await state in sharedViewModel.residencesState {
        await MainActor.run {
            self.residences = (state as? ApiResultSuccess)?.data
        }
    }
}
```

### Android Layer

Android uses Compose UI directly from `composeApp` with shared ViewModels. Navigation via Jetpack Compose Navigation in `App.kt`.

## Environment Configuration

**API Environment Toggle** (`composeApp/src/commonMain/kotlin/com/example/mycrib/network/ApiConfig.kt`):

```kotlin
val CURRENT_ENV = Environment.DEV  // or Environment.LOCAL
```

- `Environment.LOCAL`: Points to `http://10.0.2.2:8000/api` (Android emulator) or `http://127.0.0.1:8000/api` (iOS simulator)
- `Environment.DEV`: Points to `https://mycrib.treytartt.com/api`

**Change this to switch between local Django backend and production server.**

## Common Development Patterns

### Adding a New API Endpoint

1. Add API call to appropriate `*Api.kt` class in `network/` (e.g., `TaskApi.kt`)
2. Add method to `APILayer.kt` that manages caching (if applicable)
3. Add method to relevant ViewModel that calls APILayer
4. Update UI to observe the new StateFlow

### Handling Platform-Specific Code

Use `expect/actual` pattern:

```kotlin
// commonMain
expect fun platformSpecificFunction(): String

// androidMain
actual fun platformSpecificFunction(): String = "Android"

// iosMain
actual fun platformSpecificFunction(): String = "iOS"
```

### Type Conversions for iOS

Kotlin types bridge to Swift with special wrappers:
- `Double` → `KotlinDouble` (use `KotlinDouble(double:)` constructor)
- `Int` → `KotlinInt` (use `KotlinInt(int:)` constructor)
- `String` stays `String`
- Optional types: Kotlin nullable (`Type?`) becomes Swift optional (`Type?`)

**Example iOS form submission:**
```swift
// TextField uses String binding
@State private var estimatedCost: String = ""

// Convert to KotlinDouble for API
estimatedCost: estimatedCost.isEmpty ? nil : KotlinDouble(double: Double(estimatedCost) ?? 0.0)
```

### Refreshing Lists After Mutations

**iOS Pattern:**
```swift
.sheet(isPresented: $showingAddForm) {
    AddFormView(
        isPresented: $showingAddForm,
        onSuccess: {
            viewModel.loadData(forceRefresh: true)
        }
    )
}
```

**Android Pattern:**
```kotlin
// Use savedStateHandle to pass refresh flag between screens
navController.previousBackStackEntry?.savedStateHandle?.set("refresh", true)
navController.popBackStack()

// In destination composable
val shouldRefresh = backStackEntry.savedStateHandle.get<Boolean>("refresh") ?: false
LaunchedEffect(shouldRefresh) {
    if (shouldRefresh) viewModel.loadData(forceRefresh = true)
}
```

## Testing

Currently tests are minimal. When adding tests:
- Android: Place in `composeApp/src/androidUnitTest/` or `composeApp/src/commonTest/`
- iOS: Use XCTest framework in Xcode project

## Key Dependencies

- Kotlin Multiplatform: 2.1.0
- Compose Multiplatform: 1.7.1
- Ktor Client: Network requests
- kotlinx.serialization: JSON serialization
- kotlinx.coroutines: Async operations
- SKIE: Kotlin ↔ Swift interop improvements

## Important Notes

### Committing Changes

When committing changes that span both iOS and Android, commit them together in the KMM repository. If backend changes are needed, commit separately in the `myCribAPI` repository.

### Data Cache Initialization

**Critical**: After user login, call `APILayer.initializeLookups()` to populate DataCache with reference data. Without this, dropdowns and pickers will be empty.

```kotlin
// After successful login
val initResult = APILayer.initializeLookups()
if (initResult is ApiResult.Success) {
    // Navigate to main screen
}
```

### iOS Build Issues

If iOS build fails with type mismatch errors:
1. Check that cost fields (estimatedCost, actualCost, purchasePrice) use `KotlinDouble`, not `String`
2. Verify preview/mock data matches current model signatures
3. Clean build folder in Xcode (Cmd+Shift+K) and rebuild

### Force Refresh Pattern

Always use `forceRefresh: true` when data should be fresh:
- After creating/updating/deleting items
- On pull-to-refresh gestures
- When explicitly requested by user

Without `forceRefresh`, APILayer returns cached data.

## Project Structure Summary

```
MyCribKMM/
├── composeApp/
│   └── src/
│       ├── commonMain/kotlin/com/example/mycrib/
│       │   ├── cache/          # DataCache
│       │   ├── models/         # Shared data models
│       │   ├── network/        # APILayer, API clients
│       │   ├── repository/     # Additional data repositories
│       │   ├── storage/        # TokenStorage
│       │   ├── ui/             # Compose UI (Android)
│       │   │   ├── components/ # Reusable components
│       │   │   ├── screens/    # Screen composables
│       │   │   └── theme/      # Material theme
│       │   ├── viewmodel/      # Shared ViewModels
│       │   └── App.kt          # Android navigation
│       ├── androidMain/        # Android-specific code
│       ├── iosMain/            # iOS-specific Kotlin code
│       └── commonTest/         # Shared tests
│
├── iosApp/iosApp/
│   ├── *ViewModel.swift        # Swift wrappers for Kotlin VMs
│   ├── *View.swift             # SwiftUI screens
│   ├── Components/             # Reusable SwiftUI components
│   ├── Design/                 # Design system (spacing, colors)
│   ├── Extensions/             # Swift extensions
│   ├── Helpers/                # Utility helpers
│   ├── PushNotifications/      # APNs integration
│   └── [Feature]/              # Feature-grouped files
│       ├── Task/
│       ├── Residence/
│       ├── Contractor/
│       └── Documents/
│
└── gradle/                     # Gradle wrapper and configs
```

## Related Repositories

- **Backend API**: `../myCribAPI` - Django REST Framework backend
- **Load Testing**: `../myCribAPI/locust` - Locust load testing scripts
- **Documentation**: `../myCribAPI/docs` - Server configuration guides