import 'dart:async';
import 'package:flutter/material.dart';
import '../theme/app_colors.dart';
import '../theme/app_text_styles.dart';
import '../models/distraction_type.dart';
import '../models/focus_session.dart';
import '../services/storage_service.dart';
import '../services/encouragement_service.dart';
import '../services/notification_service.dart';
import 'complete_screen.dart';

/// Focus Screen - Timer and distraction tracking
class FocusScreen extends StatefulWidget {
  final int durationMinutes;
  final EncouragementService encouragementService;

  const FocusScreen({
    super.key,
    required this.durationMinutes,
    required this.encouragementService,
  });

  @override
  State<FocusScreen> createState() => _FocusScreenState();
}

class _FocusScreenState extends State<FocusScreen> {
  late Timer _timer;
  late int _remainingSeconds;
  late DateTime _startTime;
  final List<String> _distractions = [];
  bool _isPaused = false;

  @override
  void initState() {
    super.initState();
    _remainingSeconds = widget.durationMinutes * 60;
    _startTime = DateTime.now();
    _startTimer();
  }

  void _startTimer() {
    _timer = Timer.periodic(const Duration(seconds: 1), (timer) {
      if (!_isPaused && _remainingSeconds > 0) {
        setState(() {
          _remainingSeconds--;
        });

        if (_remainingSeconds == 0) {
          _onTimerComplete();
        }
      }
    });
  }

  void _onTimerComplete() async {
    _timer.cancel();
    _saveFocusSession(completed: true);

    // Send notification
    final notificationService = NotificationService();
    await notificationService.showFocusCompletedNotification(
      minutes: widget.durationMinutes,
      distractionCount: _distractions.length,
    );

    if (!mounted) return;

    Navigator.pushReplacement(
      context,
      MaterialPageRoute(
        builder: (context) => CompleteScreen(
          focusedMinutes: widget.durationMinutes,
          distractionCount: _distractions.length,
          encouragementService: widget.encouragementService,
        ),
      ),
    );
  }

  void _togglePause() {
    setState(() {
      _isPaused = !_isPaused;
    });
  }

  void _stopEarly() {
    final actualMinutes = ((widget.durationMinutes * 60 - _remainingSeconds) / 60).floor();

    showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Stop early?'),
        content: Text(
          "That's totally fine — you still focused for $actualMinutes ${actualMinutes == 1 ? 'minute' : 'minutes'}!",
          style: AppTextStyles.bodyText,
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context),
            child: const Text('Keep going'),
          ),
          TextButton(
            onPressed: () {
              Navigator.pop(context); // Close dialog
              _timer.cancel();
              _saveFocusSession(completed: false);

              Navigator.pushReplacement(
                context,
                MaterialPageRoute(
                  builder: (context) => CompleteScreen(
                    focusedMinutes: actualMinutes,
                    distractionCount: _distractions.length,
                    encouragementService: widget.encouragementService,
                  ),
                ),
              );
            },
            child: const Text('Yes, stop'),
          ),
        ],
      ),
    );
  }

  Future<void> _saveFocusSession({required bool completed}) async {
    final actualMinutes = completed
        ? widget.durationMinutes
        : ((widget.durationMinutes * 60 - _remainingSeconds) / 60).floor();

    final session = FocusSession(
      startTime: _startTime,
      durationMinutes: widget.durationMinutes,
      actualMinutes: actualMinutes,
      distractionCount: _distractions.length,
      completed: completed,
      distractionTypes: _distractions,
    );

    final storageService = StorageService();
    await storageService.saveFocusSession(session);
  }

  void _showDistractionSheet() {
    showModalBottomSheet(
      context: context,
      backgroundColor: AppColors.white,
      isScrollControlled: true,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(24)),
      ),
      builder: (context) {
        return SafeArea(
          child: SingleChildScrollView(
            child: Padding(
              padding: EdgeInsets.only(
                left: 24.0,
                right: 24.0,
                top: 24.0,
                bottom: 24.0 + MediaQuery.of(context).viewInsets.bottom,
              ),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  // Drag handle
                  Center(
                    child: Container(
                      width: 32,
                      height: 4,
                      decoration: BoxDecoration(
                        color: AppColors.distractionButton,
                        borderRadius: BorderRadius.circular(2),
                      ),
                    ),
                  ),
                  const SizedBox(height: 24),

                  // Title
                  const Text(
                    'What pulled you away?',
                    style: TextStyle(
                      fontFamily: 'Nunito',
                      fontSize: 18,
                      fontWeight: FontWeight.w600,
                      color: AppColors.textPrimary,
                    ),
                  ),
                  const SizedBox(height: 24),

                  // Distraction options
                  ...DistractionType.all.map((type) {
                    return Column(
                      children: [
                        ListTile(
                          leading: Text(
                            DistractionType.getEmoji(type),
                            style: const TextStyle(fontSize: 24),
                          ),
                          title: Text(
                            DistractionType.getDisplayName(type),
                            style: AppTextStyles.bodyText,
                          ),
                          onTap: () {
                            Navigator.pop(context);
                            _recordDistraction(type);
                          },
                        ),
                        if (type != DistractionType.all.last)
                          const Divider(color: AppColors.divider),
                      ],
                    );
                  }),

                  const SizedBox(height: 16),

                  // Skip button
                  Center(
                    child: TextButton(
                      onPressed: () {
                        Navigator.pop(context);
                        _recordDistraction(null);
                      },
                      child: const Text('Skip this time'),
                    ),
                  ),
                ],
              ),
            ),
          ),
        );
      },
    );
  }

  void _recordDistraction(String? type) {
    setState(() {
      if (type != null) {
        _distractions.add(type);
      }
    });

    // Show encouragement toast
    ScaffoldMessenger.of(context).showSnackBar(
      const SnackBar(
        content: Text("It happens. Let's gently come back."),
        duration: Duration(seconds: 2),
        behavior: SnackBarBehavior.floating,
      ),
    );
  }

  String _formatTime(int seconds) {
    final minutes = seconds ~/ 60;
    final secs = seconds % 60;
    return '${minutes.toString().padLeft(2, '0')}:${secs.toString().padLeft(2, '0')}';
  }

  @override
  void dispose() {
    _timer.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: AppColors.background,
      body: SafeArea(
        child: Column(
          children: [
            Expanded(
              child: SingleChildScrollView(
                padding: const EdgeInsets.all(24.0),
                child: Column(
                  children: [
                    SizedBox(
                      height: MediaQuery.of(context).size.height * 0.2,
                    ),

                    // Timer Display
                    Text(
                      _formatTime(_remainingSeconds),
                      style: AppTextStyles.timerDisplay,
                    ),

                    const SizedBox(height: 80),

                    // "I got distracted" Button
                    SizedBox(
                      width: double.infinity,
                      child: ElevatedButton(
                        onPressed: _showDistractionSheet,
                        style: ElevatedButton.styleFrom(
                          backgroundColor: AppColors.distractionButton,
                          foregroundColor: AppColors.textPrimary,
                          minimumSize: const Size(double.infinity, 48),
                          shape: RoundedRectangleBorder(
                            borderRadius: BorderRadius.circular(12),
                          ),
                          elevation: 0,
                        ),
                        child: Row(
                          mainAxisAlignment: MainAxisAlignment.center,
                          children: [
                            const Text(
                              'I got distracted',
                              style: TextStyle(
                                fontFamily: 'Nunito',
                                fontSize: 18,
                                fontWeight: FontWeight.w600,
                              ),
                            ),
                            const SizedBox(width: 8),
                            Text(
                              '🤚',
                              style: const TextStyle(fontSize: 20),
                            ),
                          ],
                        ),
                      ),
                    ),

                    const SizedBox(height: 16),

                    // Pause Button
                    SizedBox(
                      width: double.infinity,
                      child: OutlinedButton(
                        onPressed: _togglePause,
                        style: OutlinedButton.styleFrom(
                          foregroundColor: AppColors.primary,
                          side: const BorderSide(color: AppColors.primary, width: 1),
                          minimumSize: const Size(double.infinity, 48),
                          shape: RoundedRectangleBorder(
                            borderRadius: BorderRadius.circular(12),
                          ),
                        ),
                        child: Row(
                          mainAxisAlignment: MainAxisAlignment.center,
                          children: [
                            Icon(_isPaused ? Icons.play_arrow : Icons.pause),
                            const SizedBox(width: 8),
                            Text(_isPaused ? 'Resume' : 'Pause'),
                          ],
                        ),
                      ),
                    ),

                    SizedBox(
                      height: MediaQuery.of(context).size.height * 0.2,
                    ),
                  ],
                ),
              ),
            ),

            // Stop Button (text button at bottom)
            Padding(
              padding: const EdgeInsets.only(bottom: 24.0),
              child: TextButton(
                onPressed: _stopEarly,
                child: const Text(
                  'Stop session',
                  style: TextStyle(
                    color: AppColors.textSecondary,
                    fontSize: 14,
                  ),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}