player.dart

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_sound/flutter_sound.dart';
import 'package:provider/provider.dart';

import 'package:dashcast/notifiers.dart';

class PlayerPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(
          Provider.of<Podcast>(context).selectedItem.title,
        ),
      ),
      body: SafeArea(child: Player()),
    );
  }
}

class Player extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final podcast = Provider.of<Podcast>(context);
    return Column(
      children: [
        Flexible(
            flex: 8,
            child: SingleChildScrollView(
              child: Column(children: [
                Image.network(podcast.feed.image.url),
                Padding(
                  padding: const EdgeInsets.all(10),
                  child: Text(
                    podcast.selectedItem.description.trim(),
                  ),
                ),
              ]),
            )),
        Flexible(
          flex: 2,
          child: Material(
            elevation: 12,
            child: AudioControls(),
          ),
        ),
      ],
    );
  }
}

class AudioControls extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        PlaybackButtons(),
      ],
    );
  }
}

class PlaybackButtons extends StatefulWidget {
  @override
  _PlaybackButtonState createState() => _PlaybackButtonState();
}

class _PlaybackButtonState extends State<PlaybackButtons> {
  bool _isPlaying = false;
  FlutterSound _sound;
  double _playPosition;
  StreamSubscription<PlayStatus> _playerSubscription;

  @override
  void initState() {
    super.initState();
    _sound = FlutterSound();
    _playPosition = 0;
  }

  @override
  void dispose() {
    _cleanup();
    super.dispose();
  }

  void _cleanup() async {
    if (_sound.audioState == t_AUDIO_STATE.IS_PLAYING)
      await _sound.stopPlayer();
    // TODO somehow this gets called from episode list and breaks everything.
    _playerSubscription.cancel();
  }

  void _stop() async {
    await _sound.stopPlayer();
    setState(() => _isPlaying = false);
  }

  void _play(String url) async {
    await _sound.startPlayer(url);
    _playerSubscription = _sound.onPlayerStateChanged.listen((e) {
      if (e != null) {
        // print(e.currentPosition);
        setState(() => _playPosition = (e.currentPosition / e.duration));
      }
    });
    setState(() => _isPlaying = true);
  }

  void _fastForward() {}

  void _rewind() {}

  @override
  Widget build(BuildContext context) {
    final podcast = Provider.of<Podcast>(context);
    final item = podcast.selectedItem;

    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[
        Slider(
          value: _playPosition,
          onChanged: null,
        ),
        Row(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            IconButton(icon: Icon(Icons.fast_rewind), onPressed: null),
            IconButton(
              icon: _isPlaying ? Icon(Icons.stop) : Icon(Icons.play_arrow),
              onPressed: () {
                if (_isPlaying) {
                  _stop();
                } else {
                  var url = item.downloadLocation ?? item.guid;
                  print('Playing url: $url');
                  _play(url);
                }
              },
            ),
            IconButton(
              icon: Icon(Icons.fast_forward),
              onPressed: null,
            ),
          ],
        ),
      ],
    );
  }
}