school-attendance/lib/function/board_list_controller.dart

// 🗣️ 커뮤니티 게시판 - 카테고리별 게시글 목록 화면의 기능(서버 통신/상태) 담당 컨트롤러.
import 'dart:convert';
import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;
import '../config.dart';

class BoardListController extends ChangeNotifier {
  final String category;
  final String studentId;

  BoardListController({required this.category, required this.studentId});

  bool _isLoading = true;
  bool _isLoadingMore = false;
  bool _hasMore = true;
  int _page = 1;
  List<dynamic> _posts = [];
  bool _disposed = false;

  bool get isLoading => _isLoading;
  bool get isLoadingMore => _isLoadingMore;
  bool get hasMore => _hasMore;
  List<dynamic> get posts => _posts;

  static const int _pageSize = 20;

  void _safeNotify() {
    if (!_disposed) notifyListeners();
  }

  @override
  void dispose() {
    _disposed = true;
    super.dispose();
  }

  Future<void> init() => refresh();

  Future<void> refresh() async {
    _isLoading = true;
    _page = 1;
    _hasMore = true;
    _safeNotify();
    await _fetchPage(replace: true);
    _isLoading = false;
    _safeNotify();
  }

  Future<void> loadMore() async {
    if (_isLoadingMore || !_hasMore || _isLoading) return;
    _isLoadingMore = true;
    _safeNotify();
    _page += 1;
    await _fetchPage(replace: false);
    _isLoadingMore = false;
    _safeNotify();
  }

  Future<void> _fetchPage({required bool replace}) async {
    try {
      final response = await http.get(
        Uri.parse(
          '$baseUrl/api/board/posts?category=$category&studentId=$studentId&page=$_page',
        ),
      );
      if (response.statusCode == 200) {
        final data = jsonDecode(utf8.decode(response.bodyBytes));
        final fetched = (data['posts'] as List<dynamic>?) ?? [];
        _posts = replace ? fetched : [..._posts, ...fetched];
        _hasMore = fetched.length >= _pageSize;
      }
    } catch (_) {
      // 조용히 무시 - 마지막으로 받아온 목록을 유지한다.
    }
  }
}