# Fluffytrix Agent Guidelines

## Project Overview

Fluffytrix is an Android Matrix chat client with a Discord-like UI. Built with Kotlin, targeting Android 14+ (minSdk 34, targetSdk 36, compileSdk 36).

**Package**: `com.example.fluffytrix`  
**Build system**: Gradle with KotlinDSL, version catalog at `gradle/libs.versions.toml`  
**DI**: Koin  
**State management**: Jetpack Compose StateFlow, ViewModel  
**UI framework**: Jetpack Compose with Material 3 (Dynamic Colors)  
**Protocol**: Trixnity SDK for Matrix  
**Storage**: Room Database, DataStore Preferences  
**Async**: Kotlin Coroutines

---

## Build Commands

```bash
./gradlew assembleDebug          # Build debug APK (minified for performance)
./gradlew assembleRelease        # Build release APK
./gradlew test                   # Run all unit tests
./gradlew connectedAndroidTest   # Run instrumented tests on device
./gradlew testDebugUnitTest --tests "com.example.fluffytrix.*"  # Run single test class
./gradlew app:testDebugUnitTest --tests "LoginViewModelTest"  # Run specific test
```

- Debug builds use R8 with `isDebuggable = true` for balanced speed/debuggability
- Instrumented tests require a connected device or emulator

---

## Testing

**Unit tests**: `app/src/test/java/`  
**Instrumented tests**: `app/src/androidTest/java/`  
**Single test**: `./gradlew testDebugUnitTest --tests "com.example.fluffytrix.ui.main.LoginViewModelTest"`

---

## Code Style Guidelines

### Kotlin Conventions

- **Android Official Kotlin style** (`kotlin.code.style=official`)
- File naming: `PascalCase.kt` (e.g., `MainViewModel.kt`)
- Class naming: `PascalCase` (e.g., `AuthRepository`, `MainViewModel`)
- Function/property naming: `camelCase` (e.g., `sendMessage`, `selectedChannel`)
- Constants: `PascalCase` for top-level constants
- **Never use underscores in variable names**

### Imports

- Explicit imports only (no wildcards)
- Group: Android/X → Kotlin → Javax/Java → Third-party → Same package
- Example:
  ```kotlin
  import android.os.Bundle
  import androidx.compose.material3.Text
  import kotlinx.coroutines.flow.StateFlow
  import net.folivo.trixnity.client.MatrixClient
  import com.example.fluffytrix.ui.theme.FluffytrixTheme
  ```

### Types & Error Handling

- Prefer `val` over `var` (immutable data)
- Use `StateFlow<T>` for observable ViewModel state, `Flow<T>` for read-only streams
- Use `suspend` for async operations, `Result<T>` for failing operations
- `try-catch` with `catch (_: Exception) { }` for graceful degradation in ViewModels
- Use `?:` operators when appropriate, **never crash on recoverable errors**

### Compose & ViewModels

- Use `@Composable` for all UI functions; use `MaterialTheme` for consistent theming
- Discord-like layout: space sidebar → channel list → message area → member list
- Use `Modifier.padding()`, `wrapContentWidth()`, `fillMaxWidth()` appropriately
- Inject deps via constructor with Koin; use `viewModelScope` for coroutines
- Cache expensive operations (e.g., `messageCache`, `memberCache`)

### Coroutines & Data Layer

- `Dispatchers.Default` for CPU work, `Dispatchers.IO` for I/O operations
- Cancel jobs on ViewModel cleanup: `job?.cancel()`
- Use `Room` for persistent storage; `DataStore Preferences` for small key-value data
- Prefer Flow-based APIs; cache in ViewModels

### Naming Conventions

- State Flow: `_state` (private) / `state` (public)
- Repositories: `AuthRepository`, `MessageRepository`  
- ViewModels: `MainViewModel`, `LoginViewModel`
- UI composables: `MainScreen`, `ChannelList`, `MessageItem`
- Models: `MessageItem`, `ChannelItem`, `SpaceItem`
- Matrix IDs: Use `RoomId`, `UserId` types; access `.full` for strings

---

## Architecture Patterns

**Layered Architecture**:
```
ui/          — ViewModels, Screens, Navigation
data/        — Repositories, storage, models
di/          — Koin modules
ui/theme/    — Material 3 Theme
```

**Koin DI**: 
- `appModule`: ViewModel injection
- `dataModule`: Singleton repositories/UI Flow: NavHost in `MainActivity` with `FluffytrixTheme`, ViewModels expose StateFlow, screens observe with `collectAsState()`

---

## Key Dependencies

- **Compose BOM**: `2025.06.00`, **Kotlin**: `2.2.10`, **AGP**: `9.0.1`
- **Koin**: `4.1.1`, **Trixnity**: `4.22.7`, **Ktor**: `3.3.0`
- **Coroutines**: `1.10.2`, **DataStore**: `1.1.7`, **Coil**: `3.2.0`