import 'road_alert_models.dart';

class CommunityTrafficParser {
  static List<RoadAlert> parseAlertsJson(
    Map<String, dynamic> json, {
    required String providerId,
    required String providerName,
  }) {
    final List<RoadAlert> alerts = [];
    final rawAlerts = json['alerts'] ?? json['incidents'] ?? [];

    if (rawAlerts is! List) return alerts;

    for (var item in rawAlerts) {
      if (item is! Map<String, dynamic>) continue;

      final id = item['id']?.toString() ?? item['uuid']?.toString() ?? '${item['latitude'] ?? item['locationY']}_${item['longitude'] ?? item['locationX']}';
      final typeStr = (item['type'] ?? item['category'] ?? item['typeGroup'] ?? '').toString().toUpperCase();
      final subTypeStr = (item['subType'] ?? item['subtype'] ?? item['subCategory'] ?? '').toString().toUpperCase();

      final category = mapTypeToCategory(typeStr, subTypeStr);

      final double? lat = _toDouble(item['latitude'] ?? item['lat'] ?? item['locationY'] ?? (item['location'] != null ? (item['location']['lat'] ?? item['location']['y']) : null));
      final double? lng = _toDouble(item['longitude'] ?? item['lon'] ?? item['lng'] ?? item['locationX'] ?? (item['location'] != null ? (item['location']['lng'] ?? item['location']['x']) : null));

      if (lat == null || lng == null) continue;

      final double? heading = _toDouble(item['heading'] ?? item['magvar'] ?? item['bearing'] ?? item['direction']);
      final String? street = item['street']?.toString() ?? item['road']?.toString() ?? item['locationName']?.toString();
      final String description = _buildDescription(typeStr, subTypeStr, item['reportDescription'] ?? item['description']);

      final now = DateTime.now();
      final dynamic rawTs = item['timestamp'] ?? item['pubMillis'];
      final int nMinutesOld = rawTs != null
          ? ((now.millisecondsSinceEpoch - (rawTs is num ? rawTs.toInt() : (int.tryParse(rawTs.toString()) ?? now.millisecondsSinceEpoch))) / 60000).clamp(0, 180).toInt()
          : 5;

      final reportedAt = now.subtract(Duration(minutes: nMinutesOld));
      final expiresAt = now.add(const Duration(minutes: 30));

      final double? confidence = _toDouble(item['confidence'] ?? item['reliability'] ?? item['nThumbsUp'] ?? item['thumbs_up']);
      final severity = _mapSeverity(item['severity'] ?? item['reliability'] ?? item['reportRating']);

      alerts.add(RoadAlert(
        id: id,
        providerId: providerId,
        category: category,
        latitude: lat,
        longitude: lng,
        heading: heading,
        roadName: street,
        description: description,
        reportedAt: reportedAt,
        expiresAt: expiresAt,
        lastUpdated: now,
        confidence: confidence != null ? (confidence > 1.0 ? confidence / 10.0 : confidence) : 0.8,
        severity: severity,
        source: providerName,
        sourceType: RoadAlertSourceType.userReported,
      ));
    }

    return alerts;
  }

  static RoadAlertCategory mapTypeToCategory(String type, String subtype) {
    final combined = '${type}_$subtype';

    if (combined.contains('POLICE') ||
        type == 'POLICE' ||
        subtype.contains('POLICE_VISIBLE') ||
        subtype.contains('POLICE_HIDDEN') ||
        subtype.contains('POLICE_TRAP')) {
      return RoadAlertCategory.police;
    }

    if (combined.contains('SPEED_CAM') ||
        combined.contains('CAMERA') ||
        subtype.contains('SPEED_CAMERA') ||
        subtype.contains('RED_LIGHT_CAMERA')) {
      return RoadAlertCategory.speedCamera;
    }

    if (combined.contains('ACCIDENT') || type == 'ACCIDENT') {
      return RoadAlertCategory.accident;
    }

    if (combined.contains('HAZARD') || type == 'HAZARD' || subtype.contains('DEBRIS') || subtype.contains('WEATHER')) {
      return RoadAlertCategory.hazard;
    }

    if (combined.contains('ROAD_CLOSED') || combined.contains('CLOSURE') || type == 'ROAD_CLOSED') {
      return RoadAlertCategory.roadClosure;
    }

    if (combined.contains('CONSTRUCTION') || combined.contains('ROAD_WORKS') || type == 'CONSTRUCTION') {
      return RoadAlertCategory.construction;
    }

    if (combined.contains('JAM') || combined.contains('TRAFFIC') || type == 'JAM') {
      return RoadAlertCategory.traffic;
    }

    return RoadAlertCategory.other;
  }

  static String _buildDescription(String type, String subtype, dynamic rawDesc) {
    if (rawDesc != null && rawDesc.toString().trim().isNotEmpty) {
      return rawDesc.toString();
    }
    if (subtype.contains('POLICE_HIDDEN')) return 'Police reported hidden on shoulder';
    if (subtype.contains('POLICE_VISIBLE')) return 'Police reported visible ahead';
    if (type == 'POLICE') return 'Police report in area';
    if (subtype.contains('SPEED_CAMERA')) return 'Speed enforcement camera reported';
    if (type == 'ACCIDENT') return 'Traffic accident reported';
    if (type == 'HAZARD') return 'Road hazard reported';
    if (type == 'ROAD_CLOSED') return 'Road closed';
    if (type == 'CONSTRUCTION') return 'Construction zone';
    return 'Community traffic report';
  }

  static RoadAlertSeverity _mapSeverity(dynamic val) {
    if (val == null) return RoadAlertSeverity.medium;
    final num n = (val is num) ? val : num.tryParse(val.toString()) ?? 5;
    if (n >= 8) return RoadAlertSeverity.critical;
    if (n >= 5) return RoadAlertSeverity.high;
    if (n >= 3) return RoadAlertSeverity.medium;
    return RoadAlertSeverity.low;
  }

  static double? _toDouble(dynamic val) {
    if (val == null) return null;
    if (val is num) return val.toDouble();
    return double.tryParse(val.toString());
  }
}