Architecture

Openza Tasks follows Clean Architecture principles with a clear separation of concerns.

Project Structure

lib/
├── app/                    # Application setup
│   ├── app.dart           # Root widget
│   ├── app_router.dart    # Navigation (GoRouter)
│   └── app_theme.dart     # Material theme
│
├── core/                   # Shared utilities
│   ├── constants/         # App-wide constants
│   ├── errors/            # Error handling
│   ├── services/          # Core services
│   └── utils/             # Utilities
│
├── data/                   # Data layer
│   ├── datasources/
│   │   ├── local/         # SQLite (Drift)
│   │   └── remote/        # API clients
│   ├── models/            # Data transfer objects
│   ├── repositories/      # Repository implementations
│   ├── services/          # Data services
│   └── sync/              # Rust FFI bridge
│       ├── sync_engine.dart
│       └── sync_ffi.dart
│
├── domain/                 # Business logic
│   ├── entities/          # Domain entities (Freezed)
│   ├── repositories/      # Repository interfaces
│   └── usecases/          # Business logic
│
├── presentation/          # UI layer
│   ├── providers/         # Riverpod providers
│   ├── screens/           # UI screens
│   └── widgets/           # Reusable components
│
├── services/              # Application services
│   ├── auth/              # Authentication services
│   └── token/             # Token management
│
└── main.dart              # Entry point

rust/                       # Rust sync engine
├── src/
│   ├── api.rs             # Todoist API client
│   ├── db/                # SQLite repository
│   ├── domain/            # Models and errors
│   ├── ffi.rs             # FFI exports
│   ├── lib.rs             # Crate entry
│   └── sync/              # Sync engine logic
└── Cargo.toml

Key Technologies

Layer	Technology
State Management	Riverpod 3
Navigation	GoRouter
Database	Drift (SQLite)
Sync Engine	Rust + FFI
HTTP Client	Dio (Dart), reqwest (Rust)
Code Generation	Freezed, Riverpod Generator
Secure Storage	flutter_secure_storage

Data Flow

UI (Screens) → Providers → Use Cases → Repositories → Data Sources

1. UI triggers actions through Riverpod providers
2. Providers call use cases for business logic
3. Use Cases orchestrate repository calls
4. Repositories abstract data source access
5. Data Sources handle API calls and local storage