import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';

import '../../../../core/theme/app_theme_extension.dart';
import 'package:flutter_animate/flutter_animate.dart';
import '../../../../core/services/auth_service.dart';
import '../../../../core/services/gamification_service.dart';
import '../../../../core/models/class_stats.dart';

/// Analytics preview section for teacher dashboard
class TeacherAnalyticsPreviewWidget extends StatefulWidget {
  const TeacherAnalyticsPreviewWidget({super.key});

  @override
  State<TeacherAnalyticsPreviewWidget> createState() => _TeacherAnalyticsPreviewWidgetState();
}

class _TeacherAnalyticsPreviewWidgetState extends State<TeacherAnalyticsPreviewWidget> {
  List<ClassStats> _classStats = [];
  List<StudentRanking> _topStudents = [];
  bool _loading = true;

  @override
  void initState() {
    super.initState();
    _loadAnalyticsData();
  }

  Future<void> _loadAnalyticsData() async {
    try {
      final user = AuthService.currentUser;
      if (user == null) return;

      // Obter turmas do professor
      final classesSnapshot = await FirebaseFirestore.instance
          .collection('classes')
          .where('teacherId', isEqualTo: user.uid)
          .get();

      final classStatsList = <ClassStats>[];
      
      for (final classDoc in classesSnapshot.docs) {
        final classId = classDoc.id;
        final stats = await GamificationService.getClassStats(classId);
        if (stats != null) {
          classStatsList.add(stats);
        }
      }

      // Obter melhores alunos de todas as turmas
      final allTopStudents = <StudentRanking>[];
      for (final classStats in classStatsList) {
        final ranking = await GamificationService.getClassRanking(classStats.classId);
        allTopStudents.addAll(ranking.take(3)); // Top 3 de cada turma
      }

      // Ordenar por score e pegar os melhores
      allTopStudents.sort((a, b) => b.overallScore.compareTo(a.overallScore));
      final topStudents = allTopStudents.take(4).toList();

      if (mounted) {
        setState(() {
          _classStats = classStatsList;
          _topStudents = topStudents;
          _loading = false;
        });
      }
    } catch (e) {
      print('Error loading analytics data: $e');
      if (mounted) {
        setState(() {
          _loading = false;
        });
      }
    }
  }

  int get totalStudents => _classStats.fold(0, (sum, stats) => sum + stats.totalStudents);
  int get activeStudents => _classStats.fold(0, (sum, stats) => sum + stats.activeStudents);
  double get averageProgress {
    if (_classStats.isEmpty) return 0.0;
    final totalProgress = _classStats.fold(0.0, (sum, stats) => sum + stats.averageProgress);
    return totalProgress / _classStats.length;
  }
  int get studentsNeedingSupport => _classStats.fold(0, (sum, stats) => sum + stats.studentsNeedingSupport.length);

  @override
  Widget build(BuildContext context) {
    if (_loading) {
      return const Center(child: CircularProgressIndicator());
    }

    final user = AuthService.currentUser;
    final userName = user?.displayName ?? 'Professor';
    final userEmail = user?.email ?? '';

    return Container(
          margin: const EdgeInsets.only(top: 24),
          padding: const EdgeInsets.all(20),
          decoration: BoxDecoration(
            color: Theme.of(context).colorScheme.surface,
            borderRadius: BorderRadius.circular(16),
            border: Border.all(
              color: Theme.of(context).colorScheme.outline.withOpacity(0.2),
            ),
            boxShadow: [
              BoxShadow(
                color: Theme.of(context).colorScheme.shadow.withOpacity(0.05),
                blurRadius: 10,
                offset: const Offset(0, 4),
              ),
            ],
          ),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              // Profile Header
              Row(
                children: [
                  Container(
                    width: 48,
                    height: 48,
                    decoration: BoxDecoration(
                      gradient: LinearGradient(
                        colors: [
                          AppThemeExtras.of(context).actionCardGradientStart,
                          AppThemeExtras.of(context).actionCardGradientEnd,
                        ],
                      ),
                      borderRadius: BorderRadius.circular(24),
                    ),
                    child: const Icon(
                      Icons.school,
                      color: Colors.white,
                      size: 24,
                    ),
                  ),
                  const SizedBox(width: 16),
                  Expanded(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          userName,
                          style: TextStyle(
                            color: Theme.of(context).colorScheme.onSurface,
                            fontSize: 18,
                            fontWeight: FontWeight.bold,
                          ),
                        ),
                        const SizedBox(height: 2),
                        SingleChildScrollView(
                          scrollDirection: Axis.horizontal,
                          child: Row(
                            mainAxisSize: MainAxisSize.min,
                            children: [
                              Text(
                                userEmail,
                                style: TextStyle(
                                  color: Theme.of(
                                    context,
                                  ).colorScheme.onSurfaceVariant,
                                  fontSize: 14,
                                ),
                              ),
                              if (userEmail.length > 20) ...[
                                const SizedBox(width: 8),
                                Icon(
                                  Icons.more_horiz,
                                  color: Theme.of(
                                    context,
                                  ).colorScheme.onSurfaceVariant,
                                  size: 16,
                                ),
                              ],
                            ],
                          ),
                        ),
                      ],
                    ),
                  ),
                ],
              ),
              const SizedBox(height: 20),

              // Quick Stats Row
              Row(
                children: [
                  _buildQuickStat(
                    icon: Icons.check_circle,
                    label: 'Alunos Ativos',
                    value: '$activeStudents/$totalStudents',
                    color: Theme.of(context).colorScheme.primary,
                  ),
                  const SizedBox(width: 12),
                  _buildQuickStat(
                    icon: Icons.warning_amber,
                    label: 'Precisam Apoio',
                    value: '$studentsNeedingSupport',
                    color: Theme.of(context).colorScheme.secondary,
                  ),
                  const SizedBox(width: 12),
                  _buildQuickStat(
                    icon: Icons.emoji_events,
                    label: 'Média Turma',
                    value: '${(averageProgress * 100).toInt()}%',
                    color: Theme.of(
                      context,
                    ).colorScheme.primary.withValues(alpha: 0.8),
                  ),
                ],
              ),
              const SizedBox(height: 20),

              // Top Performing Students Preview
              Row(
                children: [
                  Icon(
                    Icons.leaderboard,
                    color: Theme.of(context).colorScheme.secondary,
                    size: 20,
                  ),
                  const SizedBox(width: 8),
                  Text(
                    'Melhores Desempenhos',
                    style: TextStyle(
                      color: Theme.of(context).colorScheme.onSurface,
                      fontSize: 16,
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                ],
              ),
              const SizedBox(height: 12),

              // Student List Preview
              ..._topStudents.map((student) {
                return Padding(
                  padding: const EdgeInsets.only(bottom: 8),
                  child: _buildStudentPerformanceItem(
                    context,
                    student.studentName,
                    student.overallScore.toInt(),
                    _getScoreColor(student.overallScore),
                  ),
                );
              }),

              const SizedBox(height: 20),

              // Content Quality Alert
              Container(
                padding: const EdgeInsets.all(16),
                decoration: BoxDecoration(
                  color: Theme.of(context).colorScheme.surfaceContainerHighest,
                  borderRadius: BorderRadius.circular(12),
                  border: Border.all(
                    color: Theme.of(
                      context,
                    ).colorScheme.outline.withOpacity(0.2),
                  ),
                ),
                child: Row(
                  children: [
                    Icon(
                      Icons.info_outline,
                      color: Theme.of(context).colorScheme.primary,
                      size: 20,
                    ),
                    const SizedBox(width: 12),
                    Expanded(
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Text(
                            'Qualidade do Conteúdo',
                            style: TextStyle(
                              color: Theme.of(context).colorScheme.onSurface,
                              fontSize: 14,
                              fontWeight: FontWeight.bold,
                            ),
                          ),
                          const SizedBox(height: 2),
                          Text(
                            '${_classStats.fold(0, (sum, stats) => sum + stats.totalContent)} conteúdos • $studentsNeedingSupport alunos precisam de apoio',
                            style: TextStyle(
                              color: Theme.of(
                                context,
                              ).colorScheme.onSurfaceVariant,
                              fontSize: 12,
                            ),
                          ),
                        ],
                      ),
                    ),
                  ],
                ),
              ),
            ],
          ),
        )
        .animate()
        .slideY(
          duration: const Duration(milliseconds: 800),
          curve: Curves.easeOut,
        )
        .then(delay: const Duration(milliseconds: 400));
  }

  Widget _buildQuickStat({
    required IconData icon,
    required String label,
    required String value,
    required Color color,
  }) {
    return Expanded(
      child: Container(
        padding: const EdgeInsets.all(12),
        decoration: BoxDecoration(
          color: color.withOpacity(0.1),
          borderRadius: BorderRadius.circular(12),
          border: Border.all(color: color.withOpacity(0.3), width: 1),
        ),
        child: Column(
          children: [
            Icon(icon, color: color, size: 20),
            const SizedBox(height: 6),
            Text(
              value,
              style: TextStyle(
                color: color,
                fontSize: 16,
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 2),
            Text(
              label,
              style: TextStyle(color: color.withOpacity(0.8), fontSize: 10),
              textAlign: TextAlign.center,
              maxLines: 3,
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildStudentPerformanceItem(
    BuildContext context,
    String name,
    int score,
    Color color,
  ) {
    return Row(
      children: [
        Container(
          width: 32,
          height: 32,
          decoration: BoxDecoration(
            color: color.withOpacity(0.1),
            borderRadius: BorderRadius.circular(16),
          ),
          child: Center(
            child: Text(
              name.split(' ').map((n) => n[0]).take(2).join(),
              style: TextStyle(
                color: color,
                fontSize: 12,
                fontWeight: FontWeight.bold,
              ),
            ),
          ),
        ),
        const SizedBox(width: 12),
        Expanded(
          child: Text(
            name,
            style: TextStyle(
              color: Theme.of(context).colorScheme.onSurfaceVariant,
              fontSize: 14,
            ),
          ),
        ),
        Container(
          padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
          decoration: BoxDecoration(
            color: color.withOpacity(0.1),
            borderRadius: BorderRadius.circular(8),
          ),
          child: Text(
            '$score%',
            style: TextStyle(
              color: color,
              fontSize: 12,
              fontWeight: FontWeight.bold,
            ),
          ),
        ),
      ],
    );
  }

  Color _getScoreColor(double score) {
    if (score >= 80) return Theme.of(context).colorScheme.tertiary;
    if (score >= 60) return Theme.of(context).colorScheme.primary;
    if (score >= 40) return Theme.of(context).colorScheme.secondary;
    return Theme.of(context).colorScheme.error;
  }
}