// ignore_for_file: deprecated_member_use
import 'dart:html' as html;
import 'dart:convert';
import 'dart:typed_data';
import 'dart:math' as math;

class TeddyAudio {
  final html.AudioElement _audio = html.AudioElement();
  bool enabled = false;
  String status = 'Audio disabled on this device';
  String? _url;
  int _generation = 0;
  TeddyAudio() {
    _audio.onEnded.listen((_) { status = 'Cue finished'; });
    _audio.onError.listen((_) { status = 'Browser audio error ${_audio.error?.code}. Use Play current hint here to retry.'; });
  }
  Future<void> enable() async {
    // Unlock this exact media element in the user's tap handler (required on phones).
    final data = ByteData(16044);
    void text(int offset, String value) { for (var i=0;i<value.length;i++) { data.setUint8(offset+i,value.codeUnitAt(i)); } }
    text(0,'RIFF'); data.setUint32(4,16036,Endian.little); text(8,'WAVEfmt ');
    data.setUint32(16,16,Endian.little); data.setUint16(20,1,Endian.little);
    data.setUint16(22,1,Endian.little); data.setUint32(24,8000,Endian.little);
    data.setUint32(28,16000,Endian.little); data.setUint16(32,2,Endian.little);
    data.setUint16(34,16,Endian.little); text(36,'data'); data.setUint32(40,16000,Endian.little);
    for (var i=0;i<8000;i++) { data.setInt16(44+i*2,(4000*math.sin(2*math.pi*440*i/8000)).round(),Endian.little); }
    _audio.src = 'data:audio/wav;base64,${base64Encode(data.buffer.asUint8List())}';
    try {
      await _audio.play();
      enabled = true;
      _url = null;
      status = 'Speaker test playing (one-second tone)';
    } catch (_) {
      enabled = false;
      status = 'Browser blocked audio. Tap Enable audio again.';
    }
  }
  void playNow(String url) { enabled = true; sync(url, force:true); }
  void sync(String? url, {bool force=false}) {
    if (!enabled || (!force && url == _url)) return;
    _generation++;
    final generation = _generation;
    _audio.pause();
    _url = url;
    if (url == null) { status = 'Waiting for Teddy'; return; }
    _audio.src = url;
    status = 'Loading Teddy audio';
    _audio.play().then((_) {
      if (generation == _generation) status = 'Playing on this device';
    }).catchError((Object error) {
      if (generation == _generation) status = 'Playback blocked or unavailable. Tap Play current hint here.';
    });
  }
  void disable() {
    _generation++;
    enabled = false;
    _url = null;
    _audio.pause();
    status = 'Audio disabled on this device';
  }
  void dispose() { disable(); _audio.src = ''; }
}