feat: add search provider

lib/provider/spotify/search/search.dart

@@ -0,0 +1,92 @@
+part of '../spotify.dart';
+
+class SearchState<Y> extends PaginatedState<Y> {
+  final String query;
+  SearchState({
+    required super.items,
+    required super.offset,
+    required super.limit,
+    required super.hasMore,
+    required this.query,
+  });
+
+  @override
+  SearchState<Y> copyWith({
+    List<Y>? items,
+    int? offset,
+    int? limit,
+    bool? hasMore,
+    String? query,
+  }) {
+    return SearchState(
+      items: items ?? this.items,
+      offset: offset ?? this.offset,
+      limit: limit ?? this.limit,
+      hasMore: hasMore ?? this.hasMore,
+      query: query ?? this.query,
+    );
+  }
+}
+
+class SearchNotifier<Y>
+    extends FamilyPaginatedAsyncNotifier<Y, SearchState<Y>, SearchType> {
+  SearchNotifier() : super();
+
+  @override
+  fetch(arg, offset, limit) async {
+    if (state.value == null) return [];
+    final results = await spotify.search
+        .get(
+          state.value!.query,
+          types: [arg],
+          market: ref.read(userPreferencesProvider).recommendationMarket,
+        )
+        .getPage(limit, offset);
+
+    return results.expand((e) => e.items ?? <Y>[]).toList().cast<Y>();
+  }
+
+  @override
+  build(arg) async {
+    ref.watch(spotifyProvider);
+    ref.watch(
+      userPreferencesProvider.select((value) => value.recommendationMarket),
+    );
+
+    final results = await fetch(arg, 0, 10);
+
+    return SearchState<Y>(
+      items: results,
+      offset: 0,
+      limit: 10,
+      hasMore: results.length == 10,
+      query: "",
+    );
+  }
+
+  Future<void> search(String query) async {
+    if (state.value == null) return;
+
+    state = AsyncData(
+      state.value!.copyWith(
+        query: query,
+      ),
+    );
+
+    await update((state) async {
+      final results = await fetch(arg, 0, 10);
+
+      return state.copyWith(
+        items: results,
+        offset: 0,
+        limit: 10,
+        hasMore: results.length == 10,
+      );
+    });
+  }
+}
+
+final searchProvider =
+    AsyncNotifierProvider.family<SearchNotifier, SearchState, SearchType>(
+  () => SearchNotifier(),
+);

lib/provider/spotify/spotify.dart

@@ -43,6 +43,8 @@ part 'playlist/tracks.dart';
 part 'playlist/featured.dart';
 part 'playlist/generate.dart';
 
+part 'search/search.dart';
+
 part 'user/me.dart';
 
 part 'utils/mixin.dart';