syncrow-web/lib/pages/access_management/booking_system/domain/services/DebouncedBookingSystemService.dart

import 'dart:async';
import 'package:syncrow_web/pages/access_management/booking_system/domain/models/paginated_bookable_spaces.dart';
import 'package:syncrow_web/pages/access_management/booking_system/domain/services/booking_system_service.dart';

class DebouncedBookingSystemService implements BookingSystemService {
  final BookingSystemService _inner;
  final Duration debounceDuration;

  Timer? _debounceTimer;
  Completer<PaginatedBookableSpaces>? _lastCompleter;

  int? _lastPage;
  int? _lastSize;
  bool? _lastIncludeSpaces;
  String? _lastSearch;

  DebouncedBookingSystemService(
    this._inner, {
    this.debounceDuration = const Duration(milliseconds: 500),
  });

  @override
  Future<PaginatedBookableSpaces> getBookableSpaces({
    required int page,
    required int size,
    required String search,
  }) {
    _debounceTimer?.cancel();
    _lastCompleter?.completeError(StateError("Cancelled by new search"));

    final completer = Completer<PaginatedBookableSpaces>();
    _lastCompleter = completer;

    _lastPage = page;
    _lastSize = size;
    _lastSearch = search;

    _debounceTimer = Timer(debounceDuration, () async {
      try {
        final result = await _inner.getBookableSpaces(
          page: _lastPage!,
          size: _lastSize!,
          search: _lastSearch!,
        );
        if (!completer.isCompleted) {
          completer.complete(result);
        }
      } catch (e, st) {
        if (!completer.isCompleted) {
          completer.completeError(e, st);
        }
      }
    });

    return completer.future;
  }
}