import 'dart:async';
import 'dart:ui' as ui;

import 'package:audio_service/audio_service.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'app.dart';
import 'servicios/arranque_audio.dart';
import 'servicios/musica_local_auto.dart';
import 'servicios/navegacion_auto.dart';
import 'servicios/servicio_audio.dart';
import 'servicios/servicio_audio_session.dart';
import 'tema/pluriwave_tokens.dart';

const _anchoMinimoLandscape = 600.0;

/// Branded monochrome status-bar icon, replacing the default full-color
/// launcher silhouette fallback.
const androidNotificationIconResource = 'drawable/ic_stat_pluriwave';

/// S5-R8: media notification accent uses the brand color, not the M3
/// default purple. Top-level const so tests can assert it.
const configuracionAudioService = AudioServiceConfig(
  androidNotificationChannelId: 'es.freetimelab.pluriwave.audio',
  androidNotificationChannelName: 'PluriWave Radio',
  androidNotificationOngoing: true,
  androidStopForegroundOnPause: true,
  notificationColor: PluriWaveTokens.brand,
  androidNotificationIcon: androidNotificationIconResource,
);

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await _aplicarPoliticaOrientacion();

  // S3-R4: single SharedPreferences instance resolved once at startup and
  // injected into every state/service below.
  final prefs = await SharedPreferences.getInstance();

  // Android Auto browse source (Design "getChildren data source, cold-start
  // safe") — registered BEFORE the AudioService.init await below (Design
  // "Reorder handler-independent startup work before the init await"):
  // neither this nor the local-music registration depends on the
  // AudioHandler, so browse sources exist for the car even while the
  // MediaBrowser handshake (no native timeout, see arranque_audio.dart) is
  // still pending.
  final fuenteAuto = FuenteEmisorasAutoLocal();
  registrarFuenteNavegacion(fuenteAuto);

  // Local-music browse source (Design "getChildren data source
  // registration"), same injectable-prefs DI convention as every other
  // startup service — required so `_fuenteMusicaLocalGlobal` is ever
  // non-null; without this registration the local-music root would stay
  // permanently hidden (`hayCarpetaConfigurada()` has no fuente to ask).
  registrarFuenteMusicaLocal(FuenteMusicaLocalAutoImpl(prefs: prefs));

  // Silent-error channel (fix/notificacion-media): `AudioService.asyncError`
  // had ZERO subscribers app-wide, and a `PublishSubject` with no listeners
  // drops what it is given — so every exception `audio_service` catches
  // internally was discarded without a trace, which is exactly why the
  // "media notification disappeared" report came with no evidence attached.
  // Subscribed BEFORE `AudioService.init` below (the getter only touches a
  // static subject, so it needs no initialisation) so nothing reported
  // during the MediaBrowser handshake is missed, and placed here rather than
  // in `conectarHandler` so ONE subscription covers both the on-time and the
  // degraded/timeout startup paths.
  final subErroresAudio = observarErroresAudio(
    AudioService.asyncError,
    registrar: registrarErrorAudioService,
  );

  // Design "Timeout without re-init": AudioService.init is started exactly
  // ONCE here and `handlerFuturo` is the only future ever awaited for it —
  // the plugin caches state internally, so a double-configure call is
  // unsafe and must never happen, even on the degraded/timeout path below.
  final handlerFuturo = AudioService.init(
    builder: () => PluriWaveAudioHandler(),
    config: configuracionAudioService,
  );

  // S3-R1: audio focus — phone calls / transient losses pause or duck the
  // radio; headphones unplugged pauses it. Shared by both the on-time and
  // degraded/late-completion paths below.
  void conectarHandler(PluriWaveAudioHandler handler) {
    registrarHandler(handler);
    // The handler is the only thing this app ever tears down
    // (`onTaskRemoved`), so the asyncError subscription's `cancel` travels
    // with it and can never leak — same "register from main.dart" convention
    // as `registrarHandler` itself.
    registrarLimpiezaArranque(subErroresAudio.cancel);
    final sesionAudio = ServicioAudioSession(objetivo: handler);
    unawaited(sesionAudio.configurar());
  }

  Widget construirApp() => _OrientacionResponsiveApp(
    child: PluriWaveApp(prefs: prefs, fuenteAuto: fuenteAuto),
  );

  final resultado = await esperarArranqueAudio(handlerFuturo);
  switch (resultado) {
    case ArranqueAudioListo<PluriWaveAudioHandler>(:final handler):
      // Handshake finished in time — exactly today's startup path.
      conectarHandler(handler);
      runApp(construirApp());
    case ArranqueAudioPendiente<PluriWaveAudioHandler>(
      handlerFuturo: final futuroPendiente,
    ):
      // Handshake still hung after the timeout: run the app anyway with a
      // minimal loading bootstrap that keeps awaiting the SAME
      // `futuroPendiente` — identical to the outer `handlerFuturo`, per
      // esperarArranqueAudio's contract (never a second AudioService.init
      // call) — and wires the handler + swaps to the real app once it
      // eventually resolves.
      runApp(
        ArranqueAudioApp<PluriWaveAudioHandler>(
          handlerFuturo: futuroPendiente,
          alListo: conectarHandler,
          construirApp: (_) => construirApp(),
        ),
      );
  }
}

Future<void> _aplicarPoliticaOrientacion([ui.Display? display]) async {
  final vista =
      WidgetsBinding.instance.platformDispatcher.views.isNotEmpty
          ? WidgetsBinding.instance.platformDispatcher.views.first
          : null;
  final displayActivo = display ?? vista?.display;
  if (displayActivo == null) return;

  final anchoLogico = displayActivo.size.width / displayActivo.devicePixelRatio;
  if (anchoLogico < _anchoMinimoLandscape) {
    await SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp]);
    return;
  }

  await SystemChrome.setPreferredOrientations(DeviceOrientation.values);
}

class _OrientacionResponsiveApp extends StatefulWidget {
  const _OrientacionResponsiveApp({required this.child});

  final Widget child;

  @override
  State<_OrientacionResponsiveApp> createState() =>
      _OrientacionResponsiveAppState();
}

class _OrientacionResponsiveAppState extends State<_OrientacionResponsiveApp>
    with WidgetsBindingObserver {
  ui.Display? _display;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    _display = View.maybeOf(context)?.display;
    unawaited(_aplicarPoliticaOrientacion(_display));
  }

  @override
  void didChangeMetrics() {
    unawaited(_aplicarPoliticaOrientacion(_display));
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => widget.child;
}