# Traccar Client

Flutter Android app for background GPS location tracking, sending data to a Traccar server.

## Build

```bash
flutter build apk --debug
```

The APK is output to `build/app/outputs/flutter-apk/app-debug.apk`.

## Project Structure

```
lib/
  main.dart                 # App entry, dark theme, routing
  main_screen.dart          # Tracking toggle + live coordinates
  permission_screen.dart    # Pre-flight permission setup
  settings_screen.dart       # Server URL, device ID, accuracy config
  status_screen.dart        # Event log (LOCATION, SYNC, ERROR, etc.)
  preferences.dart          # SharedPreferences wrapper
  bridge/
    location_bridge.dart   # Dart↔Native MethodChannel (com.traccar.client/tracking)

android/app/src/main/kotlin/com/traccar/traccar_client/
  BridgeModule.kt           # Method channel handler
  service/LocationTrackingService.kt
  location/HeartbeatScheduler.kt  # AlarmManager heartbeat
  network/TraccarHttpClient.kt    # POST to server
  network/ConnectivityReceiver.kt
```

## Configuration

On first launch, `PermissionScreen` guides through:
1. **Location** — `locationWhenInUse` then `locationAlways` (background)
2. **Notification** — required for tracking alerts
3. **Battery** — disable Doze optimization so tracking works reliably

Then set server URL and device ID in Settings before starting tracking.

## Server Request Format

POST to `https://yourserver/?id=DEVICE_ID&lat=...&lon=...&timestamp=...&is_moving=0`

- `is_moving` = `speed > 1.0 m/s` (3.6 km/h threshold)
- Server URL and device ID come from `Preferences` (configured in Settings screen)