import '../../core/config/app_config.dart';

String _absolutePlaybackUrl(String value) {
  if (value.isEmpty || value.startsWith('http://') || value.startsWith('https://')) return value;
  final base = AppConfig.baseUrl.replaceAll(RegExp(r'/+$'), '');
  return '$base/${value.replaceFirst(RegExp(r'^/+'), '')}';
}

/// Model representing an In-Video Socratic Gatekeeping Checkpoint (فحص الفهم السقراطي)
class SocraticCheckpointModel {
  final int id;
  final int questionId;
  final String questionText;
  final int timestampSeconds;
  final int rewindSecondsOnFail;
  final String hint;
  final String pedagogicalExplanation;
  final List<SocraticOptionModel> options;

  const SocraticCheckpointModel({
    required this.id,
    this.questionId = 0,
    required this.questionText,
    required this.timestampSeconds,
    this.rewindSecondsOnFail = 45,
    this.hint = '',
    this.pedagogicalExplanation = '',
    this.options = const [],
  });

  factory SocraticCheckpointModel.fromJson(Map<String, dynamic> json) {
    final List<SocraticOptionModel> parsedOptions = [];
    if (json['options'] != null && json['options'] is List) {
      for (var opt in json['options']) {
        if (opt is Map) {
          parsedOptions.add(SocraticOptionModel.fromJson(Map<String, dynamic>.from(opt)));
        }
      }
    }

    return SocraticCheckpointModel(
      id: json['id'] is num
          ? (json['id'] as num).toInt()
          : int.tryParse((json['id'] ?? json['exam_id'] ?? '0').toString()) ?? 0,
      questionId: json['question_id'] is num
          ? (json['question_id'] as num).toInt()
          : int.tryParse(json['question_id']?.toString() ?? '0') ?? 0,
      questionText: json['question']?.toString() ?? json['question_text']?.toString() ?? 'سؤال فحص الفهم السقراطي',
      timestampSeconds: (json['timestamp_seconds'] as num?)?.toInt() ?? 120,
      rewindSecondsOnFail: (json['rewind_seconds'] as num?)?.toInt() ?? 45,
      hint: json['hint']?.toString() ?? '',
      pedagogicalExplanation: json['explanation']?.toString() ?? '',
      options: parsedOptions,
    );
  }
}

/// Model representing a single choice option in a checkpoint
class SocraticOptionModel {
  final int id;
  final String text;
  final bool isCorrect;

  const SocraticOptionModel({
    required this.id,
    required this.text,
    required this.isCorrect,
  });

  factory SocraticOptionModel.fromJson(Map<String, dynamic> json) {
    return SocraticOptionModel(
      id: (json['id'] as num?)?.toInt() ?? 0,
      text: json['text']?.toString() ?? json['option_text']?.toString() ?? '',
      isCorrect: (json['is_correct'] as bool?) ?? false,
    );
  }
}

/// Model for Lesson Playback Data (Streams, Versions, Chapters, Checkpoints)
class LessonPlaybackData {
  final int lessonId;
  final String title;
  final int durationSeconds;
  final String videoUrl;
  final String storageType;
  final List<LessonVersionModel> availableVersions;
  final List<SocraticCheckpointModel> checkpoints;
  final int? lastPositionSeconds;

  const LessonPlaybackData({
    required this.lessonId,
    required this.title,
    required this.durationSeconds,
    required this.videoUrl,
    this.storageType = 'api_upload',
    this.availableVersions = const [],
    this.checkpoints = const [],
    this.lastPositionSeconds,
  });

  factory LessonPlaybackData.fromJson(Map<String, dynamic> json) {
    final lesson = json['lesson'] is Map ? json['lesson'] as Map : {};
    final playback = json['playback'] is Map ? json['playback'] as Map : {};
    
    // Parse versions
    final List<LessonVersionModel> versions = [];
    if (json['available_versions'] is List) {
      for (var v in json['available_versions']) {
        if (v is Map) {
          versions.add(LessonVersionModel.fromJson(Map<String, dynamic>.from(v)));
        }
      }
    }

    // Parse checkpoints
    final List<SocraticCheckpointModel> points = [];
    if (json['checkpoints'] is List) {
      for (var c in json['checkpoints']) {
        if (c is Map) {
          points.add(SocraticCheckpointModel.fromJson(Map<String, dynamic>.from(c)));
        }
      }
    }

    final vidUrl = _absolutePlaybackUrl(
      playback['hls_url']?.toString() ?? playback['stream_url']?.toString() ?? playback['video_url']?.toString() ?? '',
    );

    final lastPos = (json['last_position_seconds'] ?? playback['last_position_seconds'] ?? json['progress']?['position_seconds']) as num?;

    return LessonPlaybackData(
      lessonId: (lesson['id'] as num?)?.toInt() ?? 0,
      title: lesson['title']?.toString() ?? 'الدرس التفاعلي',
      durationSeconds: (lesson['duration_seconds'] as num?)?.toInt() ?? 0,
      videoUrl: vidUrl,
      storageType: playback['storage_type']?.toString() ?? 'api_upload',
      availableVersions: versions,
      checkpoints: points,
      lastPositionSeconds: lastPos?.toInt(),
    );
  }

  LessonPlaybackData copyWith({
    int? lessonId,
    String? title,
    int? durationSeconds,
    String? videoUrl,
    String? storageType,
    List<LessonVersionModel>? availableVersions,
    List<SocraticCheckpointModel>? checkpoints,
    int? lastPositionSeconds,
  }) {
    return LessonPlaybackData(
      lessonId: lessonId ?? this.lessonId,
      title: title ?? this.title,
      durationSeconds: durationSeconds ?? this.durationSeconds,
      videoUrl: videoUrl ?? this.videoUrl,
      storageType: storageType ?? this.storageType,
      availableVersions: availableVersions ?? this.availableVersions,
      checkpoints: checkpoints ?? this.checkpoints,
      lastPositionSeconds: lastPositionSeconds ?? this.lastPositionSeconds,
    );
  }
}

/// Model for Teacher vs AI Lesson versions
class LessonVersionModel {
  final int lessonId;
  final bool isAi;
  final String teacherName;
  final String schoolName;
  final String label;
  final bool isRecommended;
  final String videoUrl;

  const LessonVersionModel({
    required this.lessonId,
    required this.isAi,
    required this.teacherName,
    required this.schoolName,
    required this.label,
    required this.isRecommended,
    required this.videoUrl,
  });

  factory LessonVersionModel.fromJson(Map<String, dynamic> json) {
    final playback = json['playback'] is Map ? json['playback'] as Map : {};
    final vidUrl = _absolutePlaybackUrl(
      playback['hls_url']?.toString() ?? playback['stream_url']?.toString() ?? playback['video_url']?.toString() ?? '',
    );

    return LessonVersionModel(
      lessonId: (json['lesson_id'] as num?)?.toInt() ?? 0,
      isAi: (json['is_ai'] as bool?) ?? false,
      teacherName: json['teacher_name']?.toString() ?? '',
      schoolName: json['school_name']?.toString() ?? '',
      label: json['label']?.toString() ?? 'شرح معتمد',
      isRecommended: (json['is_recommended'] as bool?) ?? false,
      videoUrl: vidUrl,
    );
  }
}