import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:relationship_saver/core/auth/token_store.dart';
import 'package:relationship_saver/integrations/backend/backend_gateway.dart';
import 'package:relationship_saver/integrations/backend/backend_gateway_provider.dart';
import 'package:relationship_saver/integrations/backend/models/backend_models.dart';

/// Manages authenticated session lifecycle for app-level navigation.
class SessionController extends AsyncNotifier<AuthSession?> {
  @override
  Future<AuthSession?> build() async {
    return ref.read(tokenStoreProvider).read();
  }

  Future<void> signIn({
    required SignInMethod method,
    String? email,
    String? password,
    String? idToken,
  }) async {
    state = const AsyncLoading<AuthSession?>();

    try {
      final BackendGateway gateway = ref.read(backendGatewayProvider);
      final AuthSession session = await gateway.signIn(
        SignInRequest(
          method: method,
          email: email,
          password: password,
          idToken: idToken,
        ),
      );

      // Ensure fake gateway sessions are also persisted.
      await ref.read(tokenStoreProvider).write(session);
      state = AsyncData<AuthSession?>(session);
    } catch (error, stackTrace) {
      state = AsyncError<AuthSession?>(error, stackTrace);
    }
  }

  Future<void> signOut() async {
    final BackendGateway gateway = ref.read(backendGatewayProvider);
    final TokenStore tokenStore = ref.read(tokenStoreProvider);

    try {
      await gateway.signOut();
    } catch (_) {
      // Offline-first sign-out should always clear local session.
    }

    await tokenStore.clear();
    state = const AsyncData<AuthSession?>(null);
  }

  Future<void> refreshProfile() async {
    final AuthSession? current = state.asData?.value;
    if (current == null) {
      return;
    }

    try {
      final UserProfile profile = await ref.read(backendGatewayProvider).me();
      final AuthSession updated = current.copyWith(user: profile);
      await ref.read(tokenStoreProvider).write(updated);
      state = AsyncData<AuthSession?>(updated);
    } catch (_) {
      // Keep current state if profile refresh fails.
    }
  }
}

final AsyncNotifierProvider<SessionController, AuthSession?>
sessionControllerProvider =
    AsyncNotifierProvider<SessionController, AuthSession?>(
      SessionController.new,
    );