get_flowers_use_case.dart

import 'dart:math';

const List<String> _flowers = [
  // 1st page
  'Rose',
  'Hydrangea',
  'Sunflower',
  'Daisy',
  'Orchid',
  'Lily',
  'Chrysanthemum',
  'Iris',
  'Daffodil',
  'Tulip',
  // 2st page
  'Azalea',
  'Violet',
  'Marigold',
  'Peony',
  'Begonia',
  'Gardenia',
  'Kale',
  'Geranium',
  'Hyacinth',
  'Gladiolus',
  // 3rd page
  'Amaranthus',
  'Zinnia',
  'Anemone',
  'Buttercup',
  'Pansy',
  'Aster',
  'Larkspur',
  'Petunia',
  'Delphinium',
  'Yarrow',
  // 4th page
  'Allium',
  'Gerbera daisy',
  'Astilbe',
  'Snapdragon',
  'Crocus',
  'Dianthus',
  'Cornflower',
  'Celosia',
  'Lisianthus',
  'Gypsophila',
  // 5th page
  'Liatris',
  'Agapanthus',
  'Brunia',
];

const int pageSize = 10;

class GetFlowersUseCase {
  Future<List<String>> getFlowers({int page = 0}) async {
    final start = page * pageSize;
    final end = ++page * pageSize;

    if (start >= _flowers.length) {
      return _flowers;
    }

    // Simulate a paged API call response
    final List<String> flowersList = _flowers.sublist(max(start, 0), min(end, _flowers.length)).toList();
    // Artificial delay to simulate an API call
    await Future.delayed(const Duration(milliseconds: 2500));

    return flowersList;
  }
}