/// Grocery categories a product can be assigned to.
library;

const List<String> kDefaultCategories = [
  'Fruit & vegetables',
  'Dairy & eggs',
  'Meat & fish',
  'Bread & bakery',
  'Pantry',
  'Drinks',
  'Frozen',
  'Snacks',
  'Household',
  'Personal care',
];

List<String> mergeCategories(Iterable<String> used) {
  final seen = <String>{};
  final result = <String>[];
  for (final name in [...kDefaultCategories, ...used]) {
    final trimmed = name.trim();
    if (trimmed.isEmpty) continue;
    final key = trimmed.toLowerCase();
    if (seen.contains(key)) continue;
    seen.add(key);
    result.add(trimmed);
  }
  return result;
}