import 'dart:async';

import 'package:yumi/shared/business_logic/models/res/room_res.dart';
import 'package:yumi/shared/data_sources/sources/local/user_manager.dart';
import 'package:yumi/shared/data_sources/sources/repositories/sc_room_repository_imp.dart';

class SCHomeRoomPreloadManager {
  SCHomeRoomPreloadManager._();

  static final SCHomeRoomPreloadManager instance = SCHomeRoomPreloadManager._();

  static const Duration _partyRoomCacheTtl = Duration(seconds: 30);

  Future<List<SocialChatRoomRes>>? _partyRoomsFuture;
  List<SocialChatRoomRes>? _partyRooms;
  DateTime? _partyRoomsLoadedAt;

  void preloadInitialHomeRooms() {
    final token = AccountStorage().getToken();
    if (AccountStorage().getCurrentUser() == null || token.isEmpty) {
      return;
    }
    unawaited(
      loadPartyRooms().catchError((error, stackTrace) {
        return <SocialChatRoomRes>[];
      }),
    );
  }

  Future<List<SocialChatRoomRes>> loadPartyRooms({bool forceRefresh = false}) {
    if (!forceRefresh && _hasFreshPartyRoomCache) {
      return Future.value(List<SocialChatRoomRes>.from(_partyRooms!));
    }
    if (!forceRefresh) {
      final pendingFuture = _partyRoomsFuture;
      if (pendingFuture != null) {
        return pendingFuture;
      }
    }

    final future = SCChatRoomRepository()
        .discovery(allRegion: true)
        .then((rooms) {
          _partyRooms = List<SocialChatRoomRes>.from(rooms);
          _partyRoomsLoadedAt = DateTime.now();
          return List<SocialChatRoomRes>.from(rooms);
        })
        .whenComplete(() {
          _partyRoomsFuture = null;
        });
    _partyRoomsFuture = future;
    return future;
  }

  bool get _hasFreshPartyRoomCache {
    final rooms = _partyRooms;
    final loadedAt = _partyRoomsLoadedAt;
    if (rooms == null || loadedAt == null) {
      return false;
    }
    return DateTime.now().difference(loadedAt) < _partyRoomCacheTtl;
  }
}