import 'dart:convert';
import 'dart:io';

/// Keyless current-temperature lookup for the dashboard fallback.
///
/// Open-Meteo is used deliberately: no API key, no account and a tiny JSON
/// response. Any failure returns null so the UI simply hides the row.
class WeatherService {
  Future<double?> temperatureCelsius({
    required double latitude,
    required double longitude,
  }) async {
    final uri = Uri.https('api.open-meteo.com', '/v1/forecast', {
      'latitude': latitude.toStringAsFixed(4),
      'longitude': longitude.toStringAsFixed(4),
      'current': 'temperature_2m',
      'timezone': 'auto',
    });
    final client = HttpClient()..connectionTimeout = const Duration(seconds: 8);
    try {
      final request = await client.getUrl(uri);
      request.headers.set(HttpHeaders.userAgentHeader, 'CarDash/0.6');
      final response = await request.close().timeout(
        const Duration(seconds: 10),
      );
      if (response.statusCode != HttpStatus.ok) return null;
      final body = await response.transform(utf8.decoder).join();
      final decoded = jsonDecode(body);
      if (decoded is! Map) return null;
      final current = decoded['current'];
      if (current is! Map) return null;
      final temperature = current['temperature_2m'];
      if (temperature is! num) return null;
      if (temperature < -90 || temperature > 60) return null;
      return temperature.toDouble();
    } catch (_) {
      return null;
    } finally {
      client.close(force: true);
    }
  }
}