import 'dart:async';

import 'package:flutter/foundation.dart' show debugPrint;
import 'package:google_mobile_ads/google_mobile_ads.dart';

/// GDPR/UMP consent I/O abstraction (FIX 4, code review): every other file
/// depends on this port, never on the `google_mobile_ads` UMP classes
/// (`ConsentInformation`, `ConsentForm`) directly — matches
/// `PuertoCompras`'s injection shape, and keeps this testable with zero
/// AdMob/UMP platform channels in unit tests.
abstract class PuertoConsentimiento {
  /// Requests consent info, loads-and-shows the consent form if required,
  /// and resolves whether ads may be requested afterwards
  /// (`ConsentInformation.canRequestAds()`). Implementations must NEVER
  /// throw — any underlying failure degrades to `false` (no ads served),
  /// never crashes or blocks the caller.
  Future<bool> resolver();
}

/// The SOLE UMP call site (FIX 4) — every other file depends on
/// [PuertoConsentimiento] instead.
class ServicioConsentimientoUmp implements PuertoConsentimiento {
  ServicioConsentimientoUmp({
    ConsentRequestParameters? parametros,
    Duration? timeoutActualizacion,
  }) : _parametros = parametros ?? ConsentRequestParameters(),
       _timeoutActualizacion =
           timeoutActualizacion ?? const Duration(seconds: 10);

  final ConsentRequestParameters _parametros;
  final Duration _timeoutActualizacion;

  @override
  Future<bool> resolver() async {
    try {
      // 1. Request an up-to-date consent status. FIX 2's lesson applies
      // here too: bound the callback-based wait so a callback that never
      // fires cannot hang startup.
      final actualizacionCompleter = Completer<void>();
      ConsentInformation.instance.requestConsentInfoUpdate(
        _parametros,
        () {
          if (!actualizacionCompleter.isCompleted) {
            actualizacionCompleter.complete();
          }
        },
        (error) {
          debugPrint(
            '[PluriWave][consentimiento] requestConsentInfoUpdate ERROR '
            '${error.message}',
          );
          if (!actualizacionCompleter.isCompleted) {
            actualizacionCompleter.complete();
          }
        },
      );
      await actualizacionCompleter.future.timeout(
        _timeoutActualizacion,
        onTimeout: () {},
      );

      // 2. Load-and-show the consent form ONLY IF the UMP SDK itself
      // determines it is required (EEA/UK traffic, no prior valid
      // consent) — this single call is a no-op everywhere else.
      await ConsentForm.loadAndShowConsentFormIfRequired((formError) {
        if (formError != null) {
          debugPrint(
            '[PluriWave][consentimiento] '
            'loadAndShowConsentFormIfRequired ERROR ${formError.message}',
          );
        }
      });

      // 3. The only gate that matters for the caller: may ads be
      // requested at all right now?
      return await ConsentInformation.instance.canRequestAds();
    } catch (e) {
      debugPrint('[PluriWave][consentimiento] ERROR $e');
      return false;
    }
  }
}

/// Orchestrates the whole gate (FIX 4): premium users NEVER see a consent
/// form at all — they get zero ads regardless of consent — so
/// [PuertoConsentimiento] is never even touched for them. Free-tier users
/// get the real flow, with any failure degrading silently to "ads not
/// allowed" rather than crashing or blocking `main()`.
Future<bool> resolverConsentimientoAnuncios({
  required bool esPremium,
  required PuertoConsentimiento consentimiento,
}) async {
  if (esPremium) return false;
  try {
    return await consentimiento.resolver();
  } catch (e) {
    // Defense in depth: [PuertoConsentimiento.resolver] is documented to
    // never throw, but a caller-provided implementation (fake or future
    // adapter) failing to honor that contract still may not crash or block
    // `main()`.
    debugPrint(
      '[PluriWave][consentimiento] resolverConsentimientoAnuncios ERROR $e',
    );
    return false;
  }
}