import 'dart:async';
import 'package:geolocator/geolocator.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:wakelock_plus/wakelock_plus.dart';
import '../../core/constants/gps_constants.dart';

/// Lightweight stateless wrapper around Geolocator.
///
/// Only handles platform I/O — no business logic.
class GpsService {
  static double? _lastValidHeading;

  /// Create a position stream with dynamic accuracy setting.
  static Stream<Position> createPositionStream({
    LocationAccuracy accuracy = LocationAccuracy.high,
  }) {
    return Geolocator.getPositionStream(
      locationSettings: AndroidSettings(
        accuracy: accuracy,
        distanceFilter: 0,
        intervalDuration: Duration(milliseconds: 250),
      ),
    );
  }

  static Future<bool> requestPermissions() async {
    final permission = await Permission.locationWhenInUse.request();
    return permission.isGranted;
  }

  static Future<bool> isLocationServiceEnabled() async {
    return await Geolocator.isLocationServiceEnabled();
  }

  static Future<Position?> getCurrentPosition({
    LocationAccuracy accuracy = LocationAccuracy.bestForNavigation,
    Duration timeLimit = const Duration(seconds: 60),
  }) async {
    try {
      return await Geolocator.getCurrentPosition(
        locationSettings: LocationSettings(
          accuracy: accuracy,
          timeLimit: timeLimit,
        ),
      );
    } catch (_) {
      return null;
    }
  }

  static double getCachedHeading(double heading) {
    if (heading >= GpsConfig.VALID_HEADING_MIN && heading <= GpsConfig.VALID_HEADING_MAX) {
      _lastValidHeading = heading;
      return heading;
    }
    return _lastValidHeading ?? 0.0;
  }

  static String getCompassDirection(double heading) {
    final cachedHeading = getCachedHeading(heading);
    const directions = ['N', 'NE', 'E', 'SE', 'S', 'SW', 'W', 'NW'];
    final index = ((cachedHeading + 22.5) / 45).floor() % 8;
    return directions[index];
  }

  static String formatHeading(double heading) {
    final cachedHeading = getCachedHeading(heading);
    return '${cachedHeading.round()} ${getCompassDirection(heading)}';
  }

  static Future<void> setWakeLock(bool enable) async {
    await WakelockPlus.toggle(enable: enable);
  }
}