import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../api/endpoints/search.dart';
import '../library/library_providers.dart' show dioProvider;
import '../models/search_response.dart';

final searchApiProvider = FutureProvider<SearchApi>((ref) async {
  return SearchApi(await ref.watch(dioProvider.future));
});

/// Current search query text. The screen's TextField writes here on
/// every keystroke; the resultsProvider below debounces.
class SearchQueryNotifier extends Notifier<String> {
  @override
  String build() => '';
  void set(String q) => state = q;
}

final searchQueryProvider =
    NotifierProvider<SearchQueryNotifier, String>(SearchQueryNotifier.new);

/// Debounced search results. Returns null for empty queries so the
/// screen can show a neutral empty state instead of "0 results."
///
/// Debounce: 250ms. After the wait, re-reads the live query — if the
/// user has typed more in that window, this attempt is silently
/// abandoned (returns null) and a newer attempt fires on the next
/// rebuild. No request hits the server while the user is mid-typing.
final searchResultsProvider = FutureProvider<SearchResponse?>((ref) async {
  final q = ref.watch(searchQueryProvider).trim();
  if (q.isEmpty) return null;
  await Future<void>.delayed(const Duration(milliseconds: 250));
  // Re-read the (possibly newer) query; if the user typed more, bail.
  if (ref.read(searchQueryProvider).trim() != q) return null;
  final api = await ref.watch(searchApiProvider.future);
  return api.search(q);
});