import 'package:flutter/material.dart';
import '../l10n/app_localizations.dart';
import '../theme/app_colors.dart';
import '../theme/app_text_styles.dart';
import '../models/focus_session.dart';
import '../models/achievement_config.dart';
import '../services/points_service.dart';
import '../services/storage_service.dart';
import '../services/encouragement_service.dart';
import '../services/di.dart';

/// Session Detail Screen - Shows detailed information about a past focus session
class SessionDetailScreen extends StatelessWidget {
  final FocusSession session;

  const SessionDetailScreen({super.key, required this.session});

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    final pointsService = getIt<PointsService>();
    final storageService = getIt<StorageService>();
    final encouragementService = getIt<EncouragementService>();

    // Calculate points for this session
    final pointsBreakdown = pointsService.calculateSessionPoints(session);
    final pointsEarned = pointsBreakdown['total'] as int;
    final basePoints = pointsBreakdown['basePoints'] as int;
    final honestyBonus = pointsBreakdown['honestyBonus'] as int;

    // Get user progress to show total points
    final progress = storageService.getUserProgress();
    final encouragement = encouragementService.getRandomMessage();

    // Find achievements that might have been unlocked during this session
    final sessionAchievements = _findSessionAchievements(
      session,
      storageService,
    );

    return Scaffold(
      backgroundColor: AppColors.background,
      appBar: AppBar(
        title: Text(l10n.history),
        backgroundColor: AppColors.background,
      ),
      body: SafeArea(
        child: SingleChildScrollView(
          padding: const EdgeInsets.all(24.0),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              // Session Date and Time
              _buildSessionHeader(context, l10n),

              const SizedBox(height: 18),

              // Focused Time Section
              Text(l10n.youFocusedFor, style: AppTextStyles.headline),
              const SizedBox(height: 8),
              Text(
                l10n.minutesValue(
                  session.actualMinutes,
                  l10n.minutes(session.actualMinutes),
                ),
                style: AppTextStyles.largeNumber,
              ),

              const SizedBox(height: 24),

              // Points Earned Section
              _buildPointsCard(
                context,
                l10n,
                pointsEarned,
                basePoints,
                honestyBonus,
              ),

              const SizedBox(height: 16),

              // Session Stats Card
              Container(
                width: double.infinity,
                padding: const EdgeInsets.all(24),
                decoration: BoxDecoration(
                  color: AppColors.white,
                  borderRadius: BorderRadius.circular(16),
                ),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    //Text(l10n.history, style: AppTextStyles.headline),
                    const SizedBox(height: 16),

                    _buildStatRow(
                      icon: '⏱️',
                      label: l10n.defaultFocusDuration,
                      value: l10n.minutesValue(
                        session.durationMinutes,
                        l10n.minutes(session.durationMinutes),
                      ),
                    ),
                    const SizedBox(height: 12),

                    _buildStatRow(
                      icon: '✅',
                      label: l10n.youFocusedFor,
                      value: l10n.minutesValue(
                        session.actualMinutes,
                        l10n.minutes(session.actualMinutes),
                      ),
                    ),
                    const SizedBox(height: 12),

                    _buildStatRow(
                      icon: '🤚',
                      label: 'Distractions',
                      value:
                          '${session.distractionCount} ${l10n.times(session.distractionCount)}',
                    ),
                    const SizedBox(height: 12),

                    _buildStatRow(
                      icon: '🏁',
                      label: 'Status',
                      value: session.completed
                          ? l10n.completed
                          : l10n.stoppedEarly,
                    ),
                    const SizedBox(height: 20),

                    Text(
                      '"$encouragement"',
                      style: AppTextStyles.encouragementQuote,
                    ),
                  ],
                ),
              ),

              const SizedBox(height: 16),

              // Achievements Unlocked Section
              if (sessionAchievements.isNotEmpty)
                ..._buildAchievementCards(context, l10n, sessionAchievements),

              const SizedBox(height: 24),

              // Total Points Display
              Text(
                l10n.totalPoints(progress.totalPoints),
                style: const TextStyle(
                  fontFamily: 'Nunito',
                  fontSize: 16,
                  fontWeight: FontWeight.w600,
                  color: AppColors.primary,
                ),
              ),

              const SizedBox(height: 40),
            ],
          ),
        ),
      ),
    );
  }

  /// Build session header with date and time
  Widget _buildSessionHeader(BuildContext context, AppLocalizations l10n) {
    final dateStr = session.startTime.toLocal().toString().split(' ')[0];
    final timeStr = session.startTime
        .toLocal()
        .toString()
        .split(' ')[1]
        .substring(0, 5);

    return Container(
      width: double.infinity,
      padding: const EdgeInsets.all(12),
      decoration: BoxDecoration(
        color: AppColors.white,
        borderRadius: BorderRadius.circular(12),
      ),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.center,
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          Text(
            dateStr,
            style: const TextStyle(
              fontFamily: 'Nunito',
              fontSize: 16,
              fontWeight: FontWeight.w600,
              color: AppColors.textSecondary,
            ),
          ),
          const SizedBox(width: 12),
          const Text('•', style: TextStyle(color: AppColors.textSecondary)),
          const SizedBox(width: 12),
          Text(
            timeStr,
            style: const TextStyle(
              fontFamily: 'Nunito',
              fontSize: 18,
              fontWeight: FontWeight.w700,
              color: AppColors.textPrimary,
            ),
          ),
        ],
      ),
    );
  }

  /// Build points earned card
  Widget _buildPointsCard(
    BuildContext context,
    AppLocalizations l10n,
    int pointsEarned,
    int basePoints,
    int honestyBonus,
  ) {
    return Container(
      width: double.infinity,
      padding: const EdgeInsets.all(20),
      decoration: BoxDecoration(
        color: AppColors.white,
        borderRadius: BorderRadius.circular(16),
        border: Border.all(
          color: AppColors.primary.withValues(alpha: 0.3),
          width: 2,
        ),
      ),
      child: Column(
        children: [
          // Main points display
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Text(
                l10n.earnedPoints,
                style: TextStyle(
                  fontFamily: 'Nunito',
                  fontSize: 18,
                  color: AppColors.textSecondary,
                ),
              ),
              const SizedBox(width: 8),
              Text(
                '+$pointsEarned',
                style: const TextStyle(
                  fontFamily: 'Nunito',
                  fontSize: 28,
                  fontWeight: FontWeight.bold,
                  color: AppColors.primary,
                ),
              ),
              const Text(' ⚡', style: TextStyle(fontSize: 24)),
            ],
          ),

          const SizedBox(height: 16),
          Divider(
            thickness: 1,
            color: AppColors.textSecondary.withValues(alpha: 0.2),
          ),
          const SizedBox(height: 12),

          // Points breakdown
          _buildPointRow(l10n.basePoints, '+$basePoints', AppColors.success),
          if (honestyBonus > 0) ...[
            const SizedBox(height: 8),
            _buildPointRow(
              l10n.honestyBonus,
              '+$honestyBonus',
              AppColors.success,
              subtitle: l10n.distractionsRecorded(
                session.distractionCount,
                l10n.distractions(session.distractionCount),
              ),
            ),
          ],
        ],
      ),
    );
  }

  /// Build a single point row in the breakdown
  Widget _buildPointRow(
    String label,
    String points,
    Color color, {
    String? subtitle,
  }) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 2),
      child: Column(
        children: [
          Row(
            children: [
              Text(
                '├─ ',
                style: TextStyle(
                  color: AppColors.textSecondary.withValues(alpha: 0.4),
                  fontFamily: 'Nunito',
                ),
              ),
              Text(
                label,
                style: const TextStyle(
                  fontFamily: 'Nunito',
                  fontSize: 14,
                  color: AppColors.textSecondary,
                ),
              ),
              const Spacer(),
              Text(
                points,
                style: TextStyle(
                  fontFamily: 'Nunito',
                  fontSize: 16,
                  fontWeight: FontWeight.w600,
                  color: color,
                ),
              ),
            ],
          ),
          if (subtitle != null)
            Padding(
              padding: const EdgeInsets.only(left: 24, top: 4),
              child: Row(
                children: [
                  Text(
                    subtitle,
                    style: TextStyle(
                      fontFamily: 'Nunito',
                      fontSize: 12,
                      color: AppColors.textSecondary.withValues(alpha: 0.7),
                    ),
                  ),
                ],
              ),
            ),
        ],
      ),
    );
  }

  /// Build a single stat row
  Widget _buildStatRow({
    required String icon,
    required String label,
    required String value,
  }) {
    return Row(
      children: [
        Text(icon, style: const TextStyle(fontSize: 20)),
        const SizedBox(width: 12),
        Expanded(
          child: Text(
            label,
            style: AppTextStyles.bodyText,
            overflow: TextOverflow.ellipsis,
            maxLines: 1,
          ),
        ),
        const SizedBox(width: 8),
        Text(
          value,
          style: const TextStyle(
            fontFamily: 'Nunito',
            fontSize: 16,
            fontWeight: FontWeight.w600,
            color: AppColors.textPrimary,
          ),
        ),
      ],
    );
  }

  /// Find achievements that might have been unlocked during this session
  List<AchievementConfig> _findSessionAchievements(
    FocusSession session,
    StorageService storageService,
  ) {
    final allAchievements = AchievementConfig.all;
    final unlockedAchievements = storageService
        .getUserProgress()
        .unlockedAchievements;
    final sessionAchievements = <AchievementConfig>[];

    // Get all sessions to determine the state before this one
    final allSessions = storageService.getAllSessions();
    final sessionIndex = allSessions.indexOf(session);

    // Calculate stats before this session
    int sessionsBefore = sessionIndex;
    int distractionsBefore = allSessions
        .sublist(0, sessionIndex)
        .fold(0, (sum, s) => sum + s.distractionCount);
    int minutesBefore = allSessions
        .sublist(0, sessionIndex)
        .fold(0, (sum, s) => sum + s.actualMinutes);

    // Check which achievements might have been unlocked by this session
    for (final achievement in allAchievements) {
      // Skip if not unlocked
      if (!unlockedAchievements.containsKey(achievement.id)) {
        continue;
      }

      // Check if this session could have unlocked the achievement
      bool unlockedByThisSession = false;
      switch (achievement.type) {
        case AchievementType.sessionCount:
          unlockedByThisSession =
              sessionsBefore < achievement.requiredValue &&
              (sessionsBefore + 1) >= achievement.requiredValue;
          break;
        case AchievementType.distractionCount:
          unlockedByThisSession =
              distractionsBefore < achievement.requiredValue &&
              (distractionsBefore + session.distractionCount) >=
                  achievement.requiredValue;
          break;
        case AchievementType.totalMinutes:
          unlockedByThisSession =
              minutesBefore < achievement.requiredValue &&
              (minutesBefore + session.actualMinutes) >=
                  achievement.requiredValue;
          break;
        case AchievementType.consecutiveDays:
          // Consecutive days are not directly related to a single session
          // but rather to check-ins, so we'll skip this type
          break;
      }

      if (unlockedByThisSession) {
        sessionAchievements.add(achievement);
      }
    }

    return sessionAchievements;
  }

  /// Build achievement cards for achievements unlocked in this session
  List<Widget> _buildAchievementCards(
    BuildContext context,
    AppLocalizations l10n,
    List<AchievementConfig> achievements,
  ) {
    return [
      Text(l10n.achievements, style: AppTextStyles.headline),
      const SizedBox(height: 16),
      ...achievements.map((achievement) {
        return Container(
          margin: const EdgeInsets.only(bottom: 16),
          padding: const EdgeInsets.all(20),
          decoration: BoxDecoration(
            gradient: const LinearGradient(
              colors: [Color(0xFFFFD700), Color(0xFFFFC107)],
              begin: Alignment.topLeft,
              end: Alignment.bottomRight,
            ),
            borderRadius: BorderRadius.circular(16),
            boxShadow: [
              BoxShadow(
                color: Colors.orange.withValues(alpha: 0.4),
                blurRadius: 20,
                offset: const Offset(0, 8),
              ),
            ],
          ),
          child: Column(
            children: [
              Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text(achievement.icon, style: const TextStyle(fontSize: 32)),
                  const SizedBox(width: 12),
                  Text(
                    l10n.achievementUnlocked,
                    style: const TextStyle(
                      fontFamily: 'Nunito',
                      fontSize: 18,
                      fontWeight: FontWeight.bold,
                      color: Colors.white,
                    ),
                  ),
                ],
              ),
              const SizedBox(height: 12),
              Text(
                _getLocalizedAchievementName(l10n, achievement.nameKey),
                style: const TextStyle(
                  fontFamily: 'Nunito',
                  fontSize: 20,
                  fontWeight: FontWeight.bold,
                  color: Colors.white,
                ),
              ),
              const SizedBox(height: 4),
              Text(
                _getLocalizedAchievementDesc(l10n, achievement.descKey),
                style: const TextStyle(
                  fontFamily: 'Nunito',
                  fontSize: 14,
                  color: Colors.white,
                ),
                textAlign: TextAlign.center,
              ),
              if (achievement.bonusPoints > 0)
                Padding(
                  padding: const EdgeInsets.only(top: 8),
                  child: Text(
                    '+${achievement.bonusPoints} 积分',
                    style: const TextStyle(
                      fontFamily: 'Nunito',
                      fontSize: 16,
                      fontWeight: FontWeight.w600,
                      color: Colors.white,
                    ),
                  ),
                ),
            ],
          ),
        );
      }),
    ];
  }

  /// Get localized achievement name by key
  String _getLocalizedAchievementName(AppLocalizations l10n, String key) {
    switch (key) {
      case 'achievement_first_session_name':
        return l10n.achievement_first_session_name;
      case 'achievement_sessions_10_name':
        return l10n.achievement_sessions_10_name;
      case 'achievement_sessions_50_name':
        return l10n.achievement_sessions_50_name;
      case 'achievement_sessions_100_name':
        return l10n.achievement_sessions_100_name;
      case 'achievement_honest_bronze_name':
        return l10n.achievement_honest_bronze_name;
      case 'achievement_honest_silver_name':
        return l10n.achievement_honest_silver_name;
      case 'achievement_honest_gold_name':
        return l10n.achievement_honest_gold_name;
      case 'achievement_marathon_name':
        return l10n.achievement_marathon_name;
      case 'achievement_century_name':
        return l10n.achievement_century_name;
      case 'achievement_master_name':
        return l10n.achievement_master_name;
      case 'achievement_persistence_star_name':
        return l10n.achievement_persistence_star_name;
      case 'achievement_monthly_habit_name':
        return l10n.achievement_monthly_habit_name;
      case 'achievement_centurion_name':
        return l10n.achievement_centurion_name;
      case 'achievement_year_warrior_name':
        return l10n.achievement_year_warrior_name;
      default:
        return key;
    }
  }

  /// Get localized achievement description by key
  String _getLocalizedAchievementDesc(AppLocalizations l10n, String key) {
    switch (key) {
      case 'achievement_first_session_desc':
        return l10n.achievement_first_session_desc;
      case 'achievement_sessions_10_desc':
        return l10n.achievement_sessions_10_desc;
      case 'achievement_sessions_50_desc':
        return l10n.achievement_sessions_50_desc;
      case 'achievement_sessions_100_desc':
        return l10n.achievement_sessions_100_desc;
      case 'achievement_honest_bronze_desc':
        return l10n.achievement_honest_bronze_desc;
      case 'achievement_honest_silver_desc':
        return l10n.achievement_honest_silver_desc;
      case 'achievement_honest_gold_desc':
        return l10n.achievement_honest_gold_desc;
      case 'achievement_marathon_desc':
        return l10n.achievement_marathon_desc;
      case 'achievement_century_desc':
        return l10n.achievement_century_desc;
      case 'achievement_master_desc':
        return l10n.achievement_master_desc;
      case 'achievement_persistence_star_desc':
        return l10n.achievement_persistence_star_desc;
      case 'achievement_monthly_habit_desc':
        return l10n.achievement_monthly_habit_desc;
      case 'achievement_centurion_desc':
        return l10n.achievement_centurion_desc;
      case 'achievement_year_warrior_desc':
        return l10n.achievement_year_warrior_desc;
      default:
        return key;
    }
  }
}