jinzhi/lib/features/news/application/news_controller.dart

import 'package:hooks_riverpod/hooks_riverpod.dart';

import '../data/mock_news_repository.dart';
import '../data/news_models.dart';

final newsControllerProvider = StateNotifierProvider<NewsController, NewsState>(
  (ref) => NewsController(ref.watch(mockNewsRepositoryProvider)),
);

class NewsState {
  const NewsState({
    required this.items,
    required this.refreshedAt,
    required this.hasMore,
    required this.loadingMore,
  });

  final List<NewsItem> items;
  final DateTime refreshedAt;
  final bool hasMore;
  final bool loadingMore;
}

class NewsController extends StateNotifier<NewsState> {
  NewsController(this._repository)
    : super(
        NewsState(
          items: _repository.loadFeed(),
          refreshedAt: DateTime(2026, 6, 18, 16, 11),
          hasMore: true,
          loadingMore: false,
        ),
      );

  final MockNewsRepository _repository;
  static const _pageSize = 3;

  void refresh() {
    final items = _repository.loadFeed(limit: _pageSize);
    state = NewsState(
      items: items,
      refreshedAt: DateTime.now(),
      hasMore: items.length == _pageSize,
      loadingMore: false,
    );
  }

  bool loadMore() {
    if (state.loadingMore || !state.hasMore) return state.hasMore;
    state = NewsState(
      items: state.items,
      refreshedAt: state.refreshedAt,
      hasMore: state.hasMore,
      loadingMore: true,
    );
    final next = _repository.loadFeed(
      offset: state.items.length,
      limit: _pageSize,
    );
    state = NewsState(
      items: [...state.items, ...next],
      refreshedAt: state.refreshedAt,
      hasMore: next.length == _pageSize,
      loadingMore: false,
    );
    return state.hasMore;
  }
}