import 'dart:async';
import 'dart:math';

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

/// 扬声器输出等级可视化
class SpeakerWave extends StatefulWidget {
  final FlutterSoundPlayer audioPlayer;
  final double width;
  final double height;
  final Color color;
  final bool isPlaying;

  SpeakerWave({
    required this.audioPlayer,
    this.isPlaying = false,
    this.width = 250.0,
    this.height = 40.0,
    this.color = Colors.blue,
  });

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

class _SpeakerWaveState extends State<SpeakerWave> {
  StreamSubscription? _waveformSubscription;
  int _randomWaveform = 0;
  static const _itemHeight = 10.0;
  static const _itemCount = 5;
  @override
  void initState() {
    super.initState();
    print("监听扬声器输出：${widget.audioPlayer}");

    /// 监听扬声器输出
    _waveformSubscription =
        widget.audioPlayer.onProgress?.listen((PlaybackDisposition data) {
      setState(() {
        _randomWaveform = Random().nextInt(_itemCount);
      });
      if (data.duration - data.position < Duration(milliseconds: 500)) {
        setState(() {
          _randomWaveform = 0;
        });
      }
    });
  }

  @override
  void dispose() {
    super.dispose();
    _waveformSubscription?.cancel();
    _waveformSubscription = null;
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      width: widget.width,
      height: widget.height,
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          Text(
            "扬声器输出：",
            style: TextStyle(
              height: 1,
              color: Colors.black87,
            ),
          ),
          if (widget.isPlaying) ...[
            for (var i = 0; i < _randomWaveform; i++)
              Expanded(
                child: buildActiveItem(),
              ),
            for (var i = 0; i < _itemCount - _randomWaveform; i++)
              Expanded(
                child: buildInactiveItem(),
              ),
          ] else ...[
            for (var i = 0; i < _itemCount; i++)
              Expanded(
                child: buildInactiveItem(),
              ),
          ]
        ],
      ),
    );
  }

  Widget buildActiveItem() {
    return Container(
      height: _itemHeight,
      margin: EdgeInsets.symmetric(horizontal: 3),
      decoration: BoxDecoration(
        borderRadius: BorderRadius.all(Radius.circular(5)),
        color: widget.color,
      ),
    );
  }

  Widget buildInactiveItem() {
    return Container(
      height: _itemHeight,
      margin: EdgeInsets.symmetric(horizontal: 3),
      decoration: BoxDecoration(
        borderRadius: BorderRadius.all(Radius.circular(5)),
        color: Colors.grey[300],
      ),
    );
  }
}