fix(player): serialize live stream switching

lib/servicios/servicio_audio.dart

@@ -1,5 +1,7 @@
+import 'dart:async';
 import 'dart:developer' as developer;
 
+import 'package:audio_session/audio_session.dart';
 import 'package:audio_service/audio_service.dart';
 import 'package:just_audio/just_audio.dart';
 
@@ -90,9 +92,12 @@ class ServicioAudio {
 // AudioHandler
 // ─────────────────────────────────────────────────────────────────────────────
 class PluriWaveAudioHandler extends BaseAudioHandler with SeekHandler {
+  static const _timeoutCambioFuente = Duration(seconds: 12);
+
   final AndroidEqualizer _eq = AndroidEqualizer();
 
   late final AudioPlayer _player = AudioPlayer(
+    userAgent: 'PluriWave/0.1.0 (es.freetimelab.pluriwave)',
     audioPipeline: AudioPipeline(androidAudioEffects: [_eq]),
   );
 
@@ -107,10 +112,28 @@ class PluriWaveAudioHandler extends BaseAudioHandler with SeekHandler {
   PresetEcualizador _presetActual = PresetEcualizador.flat;
   PresetEcualizador get presetActual => _presetActual;
 
+  Future<void> _colaCambiosFuente = Future<void>.value();
+  int _revisionFuente = 0;
+  bool _cambiandoFuente = false;
+
   PluriWaveAudioHandler() {
+    unawaited(_configurarSesionAudio());
     _setupStreams();
   }
 
+  Future<void> _configurarSesionAudio() async {
+    try {
+      final session = await AudioSession.instance;
+      await session.configure(const AudioSessionConfiguration.music());
+    } catch (e) {
+      developer.log(
+        '[PluriWave] No se pudo configurar AudioSession: $e',
+        name: 'ServicioAudio',
+        level: 800,
+      );
+    }
+  }
+
   void _setupStreams() {
     _player.playerStateStream.listen((state) {
       final playing = state.playing;
@@ -136,6 +159,15 @@ class PluriWaveAudioHandler extends BaseAudioHandler with SeekHandler {
     _player.playbackEventStream.listen(
       (_) {},
       onError: (Object error, StackTrace stackTrace) {
+        if (_cambiandoFuente) {
+          developer.log(
+            '[PluriWave] Error ignorado durante cambio de emisora: $error',
+            name: 'ServicioAudio',
+            level: 800,
+            stackTrace: stackTrace,
+          );
+          return;
+        }
         _gestionarErrorReproduccion(error);
       },
     );
@@ -214,33 +246,83 @@ class PluriWaveAudioHandler extends BaseAudioHandler with SeekHandler {
 
   @override
   Future<void> playMediaItem(MediaItem mediaItem) async {
+    final revision = ++_revisionFuente;
+    _colaCambiosFuente = _colaCambiosFuente
+        .catchError((_) {})
+        .then((_) => _cambiarFuente(mediaItem, revision));
+    return _colaCambiosFuente;
+  }
+
+  Future<void> _cambiarFuente(MediaItem mediaItem, int revision) async {
+    final emisora = _emisoraDesdeMediaItem(mediaItem);
     this.mediaItem.add(mediaItem);
+    emisoraActual = emisora;
+    playbackState.add(playbackState.value.copyWith(
+      processingState: AudioProcessingState.loading,
+      playing: false,
+      errorMessage: null,
+    ));
+
+    _cambiandoFuente = true;
     try {
-      await _player.stop();
-      await _player.setUrl(mediaItem.id);
-      await _player.play();
-      emisoraActual = _emisoraDesdeMediaItem(mediaItem);
+      await _player.stop().timeout(_timeoutCambioFuente);
+      if (revision != _revisionFuente) return;
+
+      await _player
+          .setAudioSource(
+            AudioSource.uri(Uri.parse(mediaItem.id), tag: mediaItem),
+            preload: false,
+          )
+          .timeout(_timeoutCambioFuente);
+      if (revision != _revisionFuente) return;
+
       await _activarEcualizador();
+      _reproducirSinBloquear(mediaItem, revision);
     } on PlayerException catch (e) {
-      _gestionarErrorReproduccion(e);
+      if (revision == _revisionFuente) {
+        _gestionarErrorReproduccion(e);
+      }
       throw Exception(_mensajeAmigable(e));
-    } on Exception catch (e) {
+    } on Exception catch (e, stackTrace) {
       developer.log(
         '[PluriWave] Error inesperado en playMediaItem: $e',
         name: 'ServicioAudio',
         level: 900,
+        stackTrace: stackTrace,
       );
-      playbackState.add(playbackState.value.copyWith(
-        processingState: AudioProcessingState.error,
-        playing: false,
-        errorMessage: 'Error inesperado al reproducir',
-      ));
-      emisoraActual = null;
-      this.mediaItem.add(null);
+      if (revision == _revisionFuente) {
+        playbackState.add(playbackState.value.copyWith(
+          processingState: AudioProcessingState.error,
+          playing: false,
+          errorMessage: 'Error inesperado al reproducir',
+        ));
+        emisoraActual = null;
+        this.mediaItem.add(null);
+      }
       rethrow;
+    } finally {
+      if (revision == _revisionFuente) {
+        _cambiandoFuente = false;
+      }
     }
   }
 
+  void _reproducirSinBloquear(MediaItem mediaItem, int revision) {
+    unawaited(
+      _player.play().catchError((Object error, StackTrace stackTrace) {
+        developer.log(
+          '[PluriWave] Error al arrancar ${mediaItem.title}: $error',
+          name: 'ServicioAudio',
+          level: 900,
+          stackTrace: stackTrace,
+        );
+        if (revision == _revisionFuente) {
+          _gestionarErrorReproduccion(error);
+        }
+      }),
+    );
+  }
+
   Future<void> _activarEcualizador() async {
     try {
       final params = await _eq.parameters;
@@ -295,6 +377,7 @@ class PluriWaveAudioHandler extends BaseAudioHandler with SeekHandler {
 
   @override
   Future<void> stop() async {
+    _revisionFuente++;
     await _player.stop();
     emisoraActual = null;
     mediaItem.add(null);