# Data Module

## Overview
The Data module is part of the core layer of the Effective Office tablet application. It handles all data operations, including API communication, local storage, and data transformations. This module implements the repository pattern to provide a clean API for the domain layer.

## Features
- API client implementation
- Local database management
- Data caching and synchronization
- Repository implementations
- Data source abstractions
- Data mapping between network, database, and domain models

## Architecture
The module follows a layered architecture:

```
data/
├── api/              # API client and service interfaces
├── database/         # Local database implementation
├── di/               # Dependency injection setup
├── mapper/           # Data mappers between different models
├── model/            # Data models (network and database entities)
├── repository/       # Repository implementations
└── source/           # Data source implementations (remote and local)
```

## Key Components

### API
- **ApiClient**: Handles HTTP communication with the backend
- **ApiService**: Defines the API endpoints and operations

### Repository
- **Repository Implementations**: Concrete implementations of domain repository interfaces
- **Data Sources**: Remote and local data source implementations

## Integration
The Data module integrates with:
- Domain module for providing repository implementations
- External libraries for networking (Ktor)

## Error Handling
The module provides error handling for:
- Network errors and timeouts
- API response errors
- Database errors
- Data mapping exceptions

## Development
### Adding a New Repository
To add a new repository:
1. Define the repository interface in the domain module
2. Create data models in the data/model package
3. Implement the repository in the data/repository package
4. Register the repository in the dependency injection setup

### Testing
The module includes:
- Unit tests for repositories and data sources
- Mock implementations for testing