import 'dart:async';
import 'dart:ui' show Locale;

import 'package:flutter/foundation.dart';
import 'package:flutter/services.dart';

import '../l10n/display_names.dart';
import '../l10n/gen/app_localizations.dart';
import '../modelos/alarma_musical.dart';

class EventoAlarmaAndroid {
  const EventoAlarmaAndroid({
    required this.alarmaId,
    required this.titulo,
    required this.accion,
    this.triggerAtMillis = 0,
    this.occurrenceAtMillis = 0,
    this.snoozeMinutes = 5,
    this.snoozeUntilMillis = 0,
  });

  /// Action reported when the native service snoozed an alarm by itself
  /// (notification "Posponer" while the app may be backgrounded/killed).
  static const accionSnoozed = 'snoozed';

  final String alarmaId;
  final String titulo;
  final String accion;
  final int triggerAtMillis;
  final int occurrenceAtMillis;
  final int snoozeMinutes;
  final int snoozeUntilMillis;

  factory EventoAlarmaAndroid.fromMap(Map<Object?, Object?> map) {
    return EventoAlarmaAndroid(
      alarmaId: map['alarmId'] as String? ?? '',
      titulo: map['alarmTitle'] as String? ?? 'PluriWave',
      accion: map['alarmAction'] as String? ?? '',
      triggerAtMillis: (map['triggerAtMillis'] as num?)?.toInt() ?? 0,
      occurrenceAtMillis: (map['occurrenceAtMillis'] as num?)?.toInt() ?? 0,
      snoozeMinutes: (map['snoozeMinutes'] as num?)?.toInt() ?? 5,
      snoozeUntilMillis: (map['snoozeUntilMillis'] as num?)?.toInt() ?? 0,
    );
  }
}

/// Active native snooze persisted by `AlarmScheduler` (Kotlin). Used on cold
/// start so Flutter (single source of truth) can import snoozes performed
/// while the engine was dead.
class EstadoSnoozeNativo {
  const EstadoSnoozeNativo({
    required this.alarmaId,
    required this.snoozeHasta,
    required this.snoozeOrigen,
  });

  final String alarmaId;
  final DateTime snoozeHasta;
  final DateTime snoozeOrigen;

  factory EstadoSnoozeNativo.fromMap(Map<Object?, Object?> map) {
    return EstadoSnoozeNativo(
      alarmaId: map['alarmId'] as String? ?? '',
      snoozeHasta: DateTime.fromMillisecondsSinceEpoch(
        (map['snoozeUntilMillis'] as num?)?.toInt() ?? 0,
      ),
      snoozeOrigen: DateTime.fromMillisecondsSinceEpoch(
        (map['snoozeOriginMillis'] as num?)?.toInt() ?? 0,
      ),
    );
  }
}

class DiagnosticoAlarmasAndroid {
  const DiagnosticoAlarmasAndroid({
    required this.puedeProgramarExactas,
    required this.notificacionesPermitidas,
    required this.puedeUsarPantallaCompleta,
    required this.ignoraOptimizacionBateria,
    required this.alarmasNativasPendientes,
    required this.fabricante,
    required this.versionSdk,
  });

  final bool puedeProgramarExactas;
  final bool notificacionesPermitidas;
  final bool puedeUsarPantallaCompleta;
  final bool ignoraOptimizacionBateria;
  final int alarmasNativasPendientes;
  final String fabricante;
  final int versionSdk;

  factory DiagnosticoAlarmasAndroid.fromMap(Map<Object?, Object?> map) {
    return DiagnosticoAlarmasAndroid(
      puedeProgramarExactas: map['canScheduleExactAlarms'] as bool? ?? true,
      notificacionesPermitidas: map['notificationsEnabled'] as bool? ?? true,
      puedeUsarPantallaCompleta: map['canUseFullScreenIntent'] as bool? ?? true,
      ignoraOptimizacionBateria:
          map['isIgnoringBatteryOptimizations'] as bool? ?? true,
      alarmasNativasPendientes: map['nativePendingAlarmsCount'] as int? ?? 0,
      fabricante: map['manufacturer'] as String? ?? 'Android',
      versionSdk: map['sdkInt'] as int? ?? 0,
    );
  }
}

class EjecucionAlarmaNativa {
  const EjecucionAlarmaNativa({
    required this.alarmaId,
    required this.gestionadaEn,
  });

  final String alarmaId;
  final DateTime gestionadaEn;

  factory EjecucionAlarmaNativa.fromMap(Map<Object?, Object?> map) {
    return EjecucionAlarmaNativa(
      alarmaId: map['alarmId'] as String? ?? '',
      gestionadaEn: DateTime.fromMillisecondsSinceEpoch(
        (map['handledAtMillis'] as num?)?.toInt() ?? 0,
      ),
    );
  }
}

abstract class PuertoAlarmasAndroid {
  Stream<EventoAlarmaAndroid> get eventosAlarma;

  /// Provides the UI localizations used to localize the alarm/station names
  /// sent to the native scheduler.
  void configurarLocalizaciones(AppLocalizations l10n);

  Future<void> programar(AlarmaMusical alarma);
  Future<void> cancelar(String alarmaId);
  Future<void> ocultarNotificacionAlarma(String alarmaId);
  Future<void> detenerSonidoNativo(String alarmaId);
  Future<bool> solicitarPermisoAlarmasExactas();
  Future<bool> solicitarPermisoNotificaciones();
  Future<bool> solicitarPermisoPantallaCompleta();
  Future<bool> solicitarExencionBateria();
  Future<void> confirmarAudioFlutter(String alarmaId);
  Future<DiagnosticoAlarmasAndroid> diagnostico();
  Future<EventoAlarmaAndroid?> obtenerEventoInicial();
  Future<List<EjecucionAlarmaNativa>> obtenerEjecucionesNativasGestionadas();
  Future<List<EstadoSnoozeNativo>> obtenerEstadoSnoozeNativo();
}

class ServicioAlarmasAndroid implements PuertoAlarmasAndroid {
  ServicioAlarmasAndroid({
    MethodChannel channel = const MethodChannel('pluriwave/alarm_scheduler'),
  }) : _channel = channel {
    _instalarHandler();
  }

  final MethodChannel _channel;

  // Instance state (S3-R2): each bridge owns its controller and l10n so
  // independent instances never share events through globals.
  final _eventosController = StreamController<EventoAlarmaAndroid>.broadcast();
  AppLocalizations? _l10n;

  AppLocalizations get _textos {
    final actual = _l10n;
    if (actual != null) return actual;
    return lookupAppLocalizations(const Locale('es'));
  }

  @override
  void configurarLocalizaciones(AppLocalizations l10n) {
    _l10n = l10n;
  }

  @override
  Stream<EventoAlarmaAndroid> get eventosAlarma => _eventosController.stream;

  @override
  Future<void> programar(AlarmaMusical alarma) async {
    final proxima = alarma.proximaProgramable;
    if (proxima == null || !alarma.activa) {
      debugPrint(
        '[PluriWave][alarmas] cancelar por inactiva/sin proxima id=${alarma.id} activa=${alarma.activa} proxima=$proxima',
      );
      await cancelar(alarma.id);
      return;
    }
    debugPrint(
      '[PluriWave][alarmas] programar id=${alarma.id} nombre=${alarma.nombre} proxima=${proxima.toIso8601String()} preaviso=${proxima.subtract(const Duration(minutes: 30)).toIso8601String()}',
    );
    final programada = await _channel.invokeMethod<bool>('scheduleAlarm', {
      'id': alarma.id,
      'title': localizedAlarmName(_textos, alarma.nombre),
      'triggerAtMillis': proxima.millisecondsSinceEpoch,
      'preNoticeAtMillis':
          alarma.snoozeHasta == null
              ? proxima
                  .subtract(const Duration(minutes: 30))
                  .millisecondsSinceEpoch
              : 0,
      'hour': alarma.hora,
      'minute': alarma.minuto,
      'scheduleType': alarma.tipoProgramacion.name,
      'weekdays': alarma.diasSemana,
      'oneShotDateMillis': alarma.fechaUnica?.millisecondsSinceEpoch,
      'snoozeUntilMillis': alarma.snoozeHasta?.millisecondsSinceEpoch,
      'snoozeOriginMillis': alarma.snoozeOrigen?.millisecondsSinceEpoch,
      'snoozeMinutes': alarma.snoozeMinutos,
      'lastHandledAtMillis':
          alarma.ultimaEjecucionGestionada?.millisecondsSinceEpoch,
      'soundOnVacation': alarma.sonarEnVacaciones,
      'stationName':
          alarma.emisora == null
              ? null
              : localizedStationName(_textos, alarma.emisora!.nombre),
      'stationUrl': alarma.emisora?.url,
      'fallbackStationName':
          alarma.emisoraFallback == null
              ? null
              : localizedStationName(_textos, alarma.emisoraFallback!.nombre),
      'fallbackStationUrl': alarma.emisoraFallback?.url,
      'fallbackSound': alarma.sonidoInterno.name,
      'volume': alarma.volumen,
      'fadeInSegundos': alarma.fadeInSegundos,
    });
    if (programada != true) {
      throw StateError(_textos.androidExactAlarmScheduleError);
    }
  }

  @override
  Future<void> cancelar(String alarmaId) =>
      _logAndInvokeVoid('cancelAlarm', {'id': alarmaId});

  @override
  Future<void> ocultarNotificacionAlarma(String alarmaId) =>
      _logAndInvokeVoid('dismissAlarmNotification', {'id': alarmaId});

  @override
  Future<void> detenerSonidoNativo(String alarmaId) =>
      _logAndInvokeVoid('stopNativeAlarmSound', {'id': alarmaId});

  @override
  Future<void> confirmarAudioFlutter(String alarmaId) =>
      _logAndInvokeVoid('confirmFlutterAudio', {'id': alarmaId});

  @override
  Future<bool> solicitarPermisoAlarmasExactas() async {
    final abierto = await _channel.invokeMethod<bool>(
      'requestExactAlarmPermission',
    );
    return abierto ?? false;
  }

  @override
  Future<bool> solicitarPermisoNotificaciones() async {
    final abierto = await _channel.invokeMethod<bool>(
      'requestPostNotificationsPermission',
    );
    return abierto ?? false;
  }

  @override
  Future<bool> solicitarPermisoPantallaCompleta() async {
    final abierto = await _channel.invokeMethod<bool>(
      'requestFullScreenIntentPermission',
    );
    return abierto ?? false;
  }

  @override
  Future<bool> solicitarExencionBateria() async {
    final abierto = await _channel.invokeMethod<bool>(
      'requestIgnoreBatteryOptimizations',
    );
    return abierto ?? false;
  }

  @override
  Future<DiagnosticoAlarmasAndroid> diagnostico() async {
    debugPrint('[PluriWave][alarmas] diagnostico android');
    final raw = await _channel.invokeMethod<Map<Object?, Object?>>(
      'diagnostics',
    );
    final diag = DiagnosticoAlarmasAndroid.fromMap(raw ?? const {});
    debugPrint(
      '[PluriWave][alarmas] diagnostico exactas=${diag.puedeProgramarExactas} notificaciones=${diag.notificacionesPermitidas} sdk=${diag.versionSdk} fabricante=${diag.fabricante}',
    );
    return diag;
  }

  @override
  Future<EventoAlarmaAndroid?> obtenerEventoInicial() async {
    final raw = await _channel.invokeMethod<Map<Object?, Object?>>(
      'getInitialAlarmIntent',
    );
    if (raw == null || raw.isEmpty) return null;
    final evento = EventoAlarmaAndroid.fromMap(raw);
    debugPrint(
      '[PluriWave][alarmas] evento inicial id=${evento.alarmaId} accion=${evento.accion}',
    );
    return evento.alarmaId.isEmpty ? null : evento;
  }

  @override
  Future<List<EjecucionAlarmaNativa>>
  obtenerEjecucionesNativasGestionadas() async {
    final raw = await _channel.invokeMethod<List<Object?>>(
      'getHandledAlarmOccurrences',
    );
    if (raw == null || raw.isEmpty) return const [];
    return raw
        .whereType<Map<Object?, Object?>>()
        .map(EjecucionAlarmaNativa.fromMap)
        .where(
          (evento) =>
              evento.alarmaId.isNotEmpty &&
              evento.gestionadaEn.millisecondsSinceEpoch > 0,
        )
        .toList();
  }

  @override
  Future<List<EstadoSnoozeNativo>> obtenerEstadoSnoozeNativo() async {
    final raw = await _channel.invokeMethod<List<Object?>>(
      'getNativeSnoozeState',
    );
    if (raw == null || raw.isEmpty) return const [];
    return raw
        .whereType<Map<Object?, Object?>>()
        .map(EstadoSnoozeNativo.fromMap)
        .where(
          (estado) =>
              estado.alarmaId.isNotEmpty &&
              estado.snoozeHasta.millisecondsSinceEpoch > 0,
        )
        .toList();
  }

  Future<void> _logAndInvokeVoid(String method, Map<String, Object?> args) {
    debugPrint('[PluriWave][alarmas] $method $args');
    return _channel.invokeMethod<void>(method, args);
  }

  // Installed once per instance from the constructor. Creating a second
  // instance over the SAME channel re-binds the platform handler to the
  // newest instance (production has exactly one instance per channel).
  void _instalarHandler() {
    _channel.setMethodCallHandler((call) async {
      if (call.method != 'alarmFired') return;
      final args = call.arguments;
      if (args is Map) {
        final evento = EventoAlarmaAndroid.fromMap(args);
        if (evento.alarmaId.isNotEmpty) {
          debugPrint(
            '[PluriWave][alarmas] evento nativo id=${evento.alarmaId} accion=${evento.accion}',
          );
          _eventosController.add(evento);
        }
      }
    });
  }
}