import 'dart:async';
import 'package:audioplayers/audioplayers.dart';
import 'package:flutter/material.dart';

class IntervalTimerPage extends StatefulWidget {
  const IntervalTimerPage({Key? key}) : super(key: key);

  @override
  _IntervalTimerPageState createState() => _IntervalTimerPageState();
}

class _IntervalTimerPageState extends State<IntervalTimerPage> {
  final Duration _warmupDuration = const Duration(seconds: 5);
  final Duration _cooldownDuration = const Duration(seconds: 5);
  final Duration _highIntensityDuration = const Duration(seconds: 4);
  final Duration _lowIntensityDuration = const Duration(seconds: 3);
  late Duration _totalDuration = const Duration(seconds: 35);
  final int _numHighIntensityBlocks = 4;
  final int _numLowIntensityBlocks = 3;
  Timer? _timer;
  int _currentBlock = 0;
  Duration _currentDuration = const Duration();
  bool _isPaused = true;

  @override
  void initState() {
    _currentDuration = _warmupDuration;
    super.initState();
  }

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

  void _startTimer() {
    _isPaused = false;
    _timer = Timer.periodic(const Duration(seconds: 1), (_) => _tick());
  }

  void _pauseTimer() {
    _isPaused = true;
    _timer?.cancel();
  }

  void _resetTimer() {
    _isPaused = true;
    _timer?.cancel();
    _currentBlock = 0;
    _currentDuration = _warmupDuration;
    _totalDuration = const Duration(minutes: 35);
    setState(() {});
  }

  Future<void> _playSoundEffect() async {
    final player = AudioPlayer();
    await player.play(UrlSource('assets/beep.mp3'));
  }

  void _tick() {
    setState(() {
      _currentDuration = Duration(
        seconds: _currentDuration.inSeconds - 1,
      );
      _totalDuration = Duration(
        seconds: _totalDuration.inSeconds - 1,
      );
      if (_currentDuration.inSeconds == 0) {
        _playSoundEffect();
      }
      if (_currentDuration.inSeconds < 0) {
        if (_currentBlock == 0) {
          // Start high intensity blocks.
          _currentBlock++;
          _currentDuration = _highIntensityDuration;
        } else if (_currentBlock <= _numHighIntensityBlocks) {
          // Start low intensity blocks.
          _currentBlock++;
          _currentDuration = _lowIntensityDuration;
        } else if (_currentBlock <=
            _numHighIntensityBlocks + _numLowIntensityBlocks) {
          // Start high intensity blocks again.
          _currentBlock++;
          _currentDuration = _highIntensityDuration;
        } else {
          // End workout.
          _currentDuration = _cooldownDuration;
          _pauseTimer();
        }
      }
    });
  }

  String _formatDuration(Duration duration) {
    String twoDigits(int n) => n.toString().padLeft(2, '0');
    final minutes = twoDigits(duration.inMinutes.remainder(60));
    final seconds = twoDigits(duration.inSeconds.remainder(60));
    return '$minutes:$seconds';
  }

  String _formatTotalDuration(Duration duration) {
    final minutes = duration.inMinutes;
    final seconds = duration.inSeconds.remainder(60);
    return _formatDuration(Duration(minutes: minutes, seconds: seconds));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: const Text('Interval Timer'),
        ),
        body: Center(
            child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text(
              _currentBlock == 0
                  ? 'Warm-up'
                  : _currentBlock <= _numHighIntensityBlocks
                      ? 'High Intensity'
                      : 'Low Intensity',
              style: const TextStyle(fontSize: 32.0),
            ),
            const SizedBox(height: 16.0),
            Text(
              _formatDuration(_currentDuration),
              style: const TextStyle(fontSize: 80.0),
            ),
            const SizedBox(height: 32.0),
            Text(
              'Total: ${_formatTotalDuration(_totalDuration)}',
              style: const TextStyle(fontSize: 24.0),
            ),
            const SizedBox(height: 32.0),
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                IconButton(
                  icon: Icon(_isPaused
                      ? Icons.play_arrow_rounded
                      : Icons.stop_rounded),
                  iconSize: 48.0,
                  onPressed: () {
                    if (_isPaused) {
                      _startTimer();
                    } else {
                      _pauseTimer();
                      _resetTimer();
                    }
                  },
                ),
                // ),
              ],
            ),
          ],
        )));
  }
}