import 'package:flutter/material.dart';
import '../../core/theme/app_colors.dart';

/// Model representing a Curriculum Subject (المادة الدراسية)
class SubjectModel {
  final String id;
  final String title;
  final String englishTitle;
  final String iconCode;
  final Color primaryColor;
  final Color secondaryColor;
  final String gradeLevel;
  final String stream;
  final int totalUnits;
  final int totalLessons;
  final double masteryScore; // 0 - 100%
  final List<CurriculumUnitModel> units;
  final List<ResourceItemModel> textbooks;
  final List<ResourceItemModel> worksheets;
  final List<SubjectExamModel> exams;

  const SubjectModel({
    required this.id,
    required this.title,
    required this.englishTitle,
    required this.iconCode,
    required this.primaryColor,
    required this.secondaryColor,
    this.gradeLevel = 'grade_10',
    this.stream = 'scientific',
    this.totalUnits = 0,
    this.totalLessons = 0,
    this.masteryScore = 0,
    this.units = const [],
    this.textbooks = const [],
    this.worksheets = const [],
    this.exams = const [],
  });

  List<CurriculumUnitModel> get semester1Units => units.where((u) => u.semester == 'semester_1').toList();
  List<CurriculumUnitModel> get semester2Units => units.where((u) => u.semester == 'semester_2').toList();
  List<CurriculumUnitModel> unitsForSemester(String semesterKey) {
    final filtered = units.where((u) => u.semester == semesterKey).toList();
    return filtered.isNotEmpty ? filtered : units;
  }

  factory SubjectModel.fromJson(String id, Map<String, dynamic> json) {
    var title = json['name']?.toString() ?? json['title']?.toString() ?? id;
    if (id == 'history_10' || title.contains('تاريخ الأردن')) {
      title = 'التاريخ (History 10)';
    }
    final englishTitle = json['english_name']?.toString() ?? '';
    
    // Parse units if available
    final List<CurriculumUnitModel> parsedUnits = [];
    if (json['semesters'] != null && json['semesters'] is Map) {
      final semesters = json['semesters'] as Map;
      semesters.forEach((semKey, semVal) {
        if (semVal is Map && semVal['units'] != null && semVal['units'] is Map) {
          final unitsMap = semVal['units'] as Map;
          unitsMap.forEach((uKey, uVal) {
            if (uVal is Map) {
              parsedUnits.add(CurriculumUnitModel.fromJson(
                uKey.toString(),
                Map<String, dynamic>.from(uVal),
                semester: semKey.toString(),
              ));
            }
          });
        }
      });
    }

    // Parse textbooks
    final List<ResourceItemModel> parsedTextbooks = [];
    final List<ResourceItemModel> parsedWorksheets = [];
    if (json['resources'] != null && json['resources'] is Map) {
      final res = json['resources'] as Map;
      if (res['textbooks'] != null && res['textbooks']['items'] is List) {
        for (var item in res['textbooks']['items']) {
          if (item is Map) {
            parsedTextbooks.add(ResourceItemModel.fromJson(Map<String, dynamic>.from(item)));
          }
        }
      }
      if (res['worksheets'] != null && res['worksheets']['items'] is List) {
        for (var item in res['worksheets']['items']) {
          if (item is Map) {
            parsedWorksheets.add(ResourceItemModel.fromJson(Map<String, dynamic>.from(item)));
          }
        }
      }
    }

    final styling = getSubjectStyling(id);

    return SubjectModel(
      id: id,
      title: title,
      englishTitle: englishTitle.isNotEmpty ? englishTitle : styling.englishTitle,
      iconCode: styling.iconCode,
      primaryColor: styling.primaryColor,
      secondaryColor: styling.secondaryColor,
      gradeLevel: json['grade_level']?.toString() ?? 'grade_10',
      stream: json['stream']?.toString() ?? 'scientific',
      totalUnits: parsedUnits.isNotEmpty ? parsedUnits.length : styling.defaultUnits,
      totalLessons: parsedUnits.fold(0, (sum, u) => sum + u.lessons.length),
      masteryScore: (json['mastery_score'] as num?)?.toDouble() ?? 0,
      units: parsedUnits,
      textbooks: parsedTextbooks,
      worksheets: parsedWorksheets,
    );
  }

  static SubjectStyling getSubjectStyling(String key) {
    final k = key.toLowerCase();
    if (k.contains('math') || k.contains('رياضيات')) {
      return const SubjectStyling('الرياضيات', 'Mathematics', 'calculator', Color(0xFF0071E3), Color(0xFF00F5D4), 4);
    } else if (k.contains('arabic') || k.contains('عربي') || k.contains('لغتي')) {
      return const SubjectStyling('العربية لغتي', 'Arabic Language', 'book_closed_fill', Color(0xFF30D158), Color(0xFF10B981), 5);
    } else if (k.contains('english') || k.contains('انجليز') || k.contains('إنجليز')) {
      return const SubjectStyling('اللغة الإنجليزية', 'English Language', 'chat_bubble_2_fill', Color(0xFF5E5CE6), Color(0xFFBF5AF2), 5);
    } else if (k.contains('islamic') || k.contains('إسلامي') || k.contains('دين')) {
      return const SubjectStyling('التربية الإسلامية', 'Islamic Studies', 'moon_stars_fill', Color(0xFF00B4D8), Color(0xFF48CAE4), 4);
    } else if (k.contains('physic') || k.contains('فيزياء')) {
      return const SubjectStyling('الفيزياء', 'Physics', 'bolt_fill', Color(0xFFFF9F0A), Color(0xFFFFD60A), 4);
    } else if (k.contains('chem') || k.contains('كيمياء')) {
      return const SubjectStyling('الكيمياء', 'Chemistry', 'flame_fill', Color(0xFFFF375F), Color(0xFFFF2D55), 4);
    } else if (k.contains('bio') || k.contains('أحياء') || k.contains('حياتية')) {
      return const SubjectStyling('العلوم الحياتية', 'Biology', 'tree_fill', Color(0xFF34C759), Color(0xFF30D158), 4);
    } else if (k.contains('earth') || k.contains('أرض') || k.contains('بيئة') || k.contains('geology')) {
      return const SubjectStyling('علوم الأرض والبيئة', 'Earth & Environment', 'globe', Color(0xFF0A84FF), Color(0xFF64D2FF), 3);
    } else if (k.contains('history') || k.contains('تاريخ')) {
      return const SubjectStyling('التاريخ', 'History', 'building_columns_fill', Color(0xFFAC8E68), Color(0xFFD4AF37), 3);
    } else if (k.contains('geo') || k.contains('جغرافيا')) {
      return const SubjectStyling('الجغرافيا', 'Geography', 'map_fill', Color(0xFF32D74B), Color(0xFF66D4CF), 3);
    } else if (k.contains('civic') || k.contains('وطنية') || k.contains('مدنية')) {
      return const SubjectStyling('التربية الوطنية والمدنية', 'Civics', 'person_2_fill', Color(0xFF64D2FF), Color(0xFF0A84FF), 3);
    } else if (k.contains('digital') || k.contains('حاسوب') || k.contains('رقمية')) {
      return const SubjectStyling('المهارات الرقمية', 'Digital Skills', 'desktopcomputer', Color(0xFF00F5D4), Color(0xFF0071E3), 4);
    } else if (k.contains('finance') || k.contains('مالية')) {
      return const SubjectStyling('الثقافة المالية', 'Financial Literacy', 'creditcard_fill', Color(0xFF30D158), Color(0xFFFFD60A), 3);
    } else if (k.contains('vocational') || k.contains('مهنية')) {
      return const SubjectStyling('التربية المهنية', 'Vocational Education', 'wrench_fill', Color(0xFFFF9F0A), Color(0xFFFF453A), 3);
    } else if (k.contains('art') || k.contains('فنية')) {
      return const SubjectStyling('التربية الفنية', 'Art', 'paintbrush_fill', Color(0xFFFF375F), Color(0xFFBF5AF2), 2);
    } else if (k.contains('sport') || k.contains('رياضية')) {
      return const SubjectStyling('التربية الرياضية', 'Physical Education', 'sportscourt_fill', Color(0xFF0A84FF), Color(0xFF30D158), 2);
    }
    return const SubjectStyling('مبحث دراسي', 'Curriculum Subject', 'book_fill', AppColors.appleBlue, AppColors.saqelCyan, 3);
  }
}

class SubjectStyling {
  final String defaultTitle;
  final String englishTitle;
  final String iconCode;
  final Color primaryColor;
  final Color secondaryColor;
  final int defaultUnits;

  const SubjectStyling(
    this.defaultTitle,
    this.englishTitle,
    this.iconCode,
    this.primaryColor,
    this.secondaryColor,
    this.defaultUnits,
  );
}

/// Model representing a Curriculum Unit (الوحدة الدراسية)
class CurriculumUnitModel {
  final String id;
  final String name;
  final String semester;
  final List<CurriculumLessonItemModel> lessons;

  const CurriculumUnitModel({
    required this.id,
    required this.name,
    this.semester = 'semester_1',
    this.lessons = const [],
  });

  factory CurriculumUnitModel.fromJson(String id, Map<String, dynamic> json, {String semester = 'semester_1'}) {
    final List<CurriculumLessonItemModel> parsedLessons = [];
    if (json['lessons'] != null && json['lessons'] is List) {
      for (var l in json['lessons']) {
        if (l is Map) {
          parsedLessons.add(CurriculumLessonItemModel.fromJson(Map<String, dynamic>.from(l)));
        }
      }
    }

    return CurriculumUnitModel(
      id: id,
      name: json['name']?.toString() ?? id,
      semester: semester,
      lessons: parsedLessons,
    );
  }
}

/// Model representing a Lesson Item inside a Unit
class CurriculumLessonItemModel {
  final String id;
  final String title;
  final List<String> outcomes;
  final String? markdownFilePath;
  final String? curriculumLessonId;
  final int durationSeconds;
  final int checkpointsCount;
  final bool isCompleted;
  final bool hasVideo;

  const CurriculumLessonItemModel({
    required this.id,
    required this.title,
    this.outcomes = const [],
    this.markdownFilePath,
    this.curriculumLessonId,
    this.durationSeconds = 0,
    this.checkpointsCount = 0,
    this.isCompleted = false,
    this.hasVideo = false,
  });

  factory CurriculumLessonItemModel.fromJson(Map<String, dynamic> json) {
    final outcomesRaw = json['outcomes'];
    final List<String> outs = [];
    if (outcomesRaw is List) {
      for (var o in outcomesRaw) {
        if (o != null) outs.add(o.toString());
      }
    }

    final filePath = json['file']?.toString();
    final jsonId = json['id']?.toString();

    // Stable, deterministic lesson ID (vital for persistent per-lesson progress tracking)
    final stableId = (jsonId != null && jsonId.isNotEmpty)
        ? jsonId
        : (filePath != null && filePath.isNotEmpty
            ? filePath.replaceAll(RegExp(r'[^a-zA-Z0-9_]'), '_')
            : 'lesson_${(json['title']?.toString() ?? 'default').hashCode.abs()}');

    // Only the server may declare a published lesson playable.
    final bool hasVideoExplicit = json['has_video'] == true;

    return CurriculumLessonItemModel(
      id: stableId,
      title: json['title']?.toString() ?? 'درس بدون عنوان',
      outcomes: outs,
      markdownFilePath: filePath,
      curriculumLessonId: json['curriculum_lesson_id']?.toString(),
      durationSeconds: (json['duration_seconds'] as num?)?.toInt() ?? 0,
      checkpointsCount: (json['checkpoints_count'] as num?)?.toInt() ?? 0,
      isCompleted: (json['is_completed'] as bool?) ?? false,
      hasVideo: hasVideoExplicit,
    );
  }
}

/// Model representing a Resource Item (PDF Textbook or Worksheet)
class ResourceItemModel {
  final String title;
  final String assetId;
  final String assetType;
  final String mimeType;
  final String type; // textbook, worksheet, summary

  const ResourceItemModel({
    required this.title,
    required this.assetId,
    required this.assetType,
    required this.mimeType,
    this.type = 'textbook',
  });

  factory ResourceItemModel.fromJson(Map<String, dynamic> json) {
    return ResourceItemModel(
      title: json['title']?.toString() ?? 'ملف وزاري',
      assetId: json['asset_id']?.toString() ?? '',
      assetType: json['asset_type']?.toString() ?? 'other',
      mimeType: json['mime_type']?.toString() ?? '',
      type: json['type']?.toString() ?? 'textbook',
    );
  }
}

/// Model representing an Exam / Question Bank item for the subject
class SubjectExamModel {
  final String id;
  final String title;
  final int questionsCount;
  final int durationMinutes;
  final double targetScore;
  final String difficulty; // easy, medium, hard, ministerial

  const SubjectExamModel({
    required this.id,
    required this.title,
    this.questionsCount = 20,
    this.durationMinutes = 40,
    this.targetScore = 100.0,
    this.difficulty = 'ministerial',
  });
}