food_hub_app/lib/views/moment.dart

import 'package:easy_refresh/easy_refresh.dart';
import 'package:flutter/material.dart';
import 'package:food_hub_app/api/moment.dart';
import 'package:food_hub_app/models/moment.dart';
import 'package:food_hub_app/widgets/moment/card.dart';
import 'package:tdesign_flutter/tdesign_flutter.dart';

class MomentPage extends StatefulWidget {
  const MomentPage({super.key});

  @override
  State<MomentPage> createState() => _MomentPageState();
}

class _MomentPageState extends State<MomentPage> {
  List<Moment> momentList = [];

  // 分页相关变量
  int _page = 1;
  final int _pageSize = 3;
  bool _hasMore = true;
  // 初始化EasyRefresh控制器
  final EasyRefreshController _freshController = EasyRefreshController(
    controlFinishRefresh: true,
    controlFinishLoad: true,
  );

  bool _showScrollToTop = false;
  final ScrollController _scrollController = ScrollController();

  @override
  void initState() {
    super.initState();
    // 初始加载数据
    _loadData(isRefresh: true);
    _scrollController.addListener(_onScroll);
  }

  @override
  void dispose() {
    _scrollController.removeListener(_onScroll);
    _freshController.dispose();
    _scrollController.dispose();
    super.dispose();
  }

  // 统一的数据加载方法
  Future<void> _loadData({required bool isRefresh}) async {
    try {
      // 如果是刷新，重置页码
      if (isRefresh) {
        _page = 1;
      }

      // 调用API获取数据，传入页码和页大小
      final result = await queryMomentByPageApi(_page, _pageSize);

      setState(() {
        if (isRefresh) {
          // 刷新时直接替换数据
          momentList = result.records;
        } else {
          // 加载更多时追加数据
          momentList.addAll(result.records);
        }

        // 判断是否还有更多数据
        _hasMore = result.current < result.pages;
        // 如果有更多数据，准备加载下一页
        if (_hasMore) {
          _page++;
        }
      });
    } catch (e) {
      // 处理错误
      debugPrint('加载数据失败: $e');
    } finally {
      _freshController.finishRefresh();
      _freshController.resetFooter();
    }
  }

  // 下拉刷新
  Future<void> _onRefresh() async {
    await _loadData(isRefresh: true);
  }

  // 上拉加载
  Future<void> _onLoad() async {
    if (_hasMore) {
      await _loadData(isRefresh: false);
      _freshController.finishLoad(IndicatorResult.success);
    } else {
      _freshController.finishLoad(IndicatorResult.noMore);
    }
  }

  void _onScroll() {
    // 当滚动距离超过300时显示返回顶部按钮
    if (_scrollController.offset > 300) {
      if (!_showScrollToTop) {
        setState(() {
          _showScrollToTop = true;
        });
      }
    } else {
      if (_showScrollToTop) {
        setState(() {
          _showScrollToTop = false;
        });
      }
    }
  }

  // 滚动到顶部
  void _scrollToTop() {
    _scrollController.animateTo(
      0,
      duration: const Duration(milliseconds: 500), // 滚动动画时长
      curve: Curves.easeInOut, // 滚动动画曲线
    );
  }

  @override
  Widget build(BuildContext context) {
    // 空状态显示
    if (momentList.isEmpty) {
      return EasyRefresh(
        controller: _freshController,
        onRefresh: _onRefresh,
        child: const TDEmpty(type: TDEmptyType.plain, emptyText: '暂无数据'),
      );
    }

    // 有数据时显示列表
    return Stack(
      children: [
        Padding(
          padding: const EdgeInsets.all(5),
          child: EasyRefresh(
            controller: _freshController,
            header: ClassicHeader(
              dragText: '下拉刷新',
              armedText: '释放刷新',
              readyText: '准备刷新',
              processingText: '刷新中...',
              processedText: '刷新完成',
              failedText: '刷新失败',
              noMoreText: '没有更多数据',
              showText: true,
              messageText: '更新于 %T',
              showMessage: true,
            ),
            footer: ClassicFooter(
              dragText: '上拉加载',
              armedText: '释放加载',
              readyText: '准备加载',
              processingText: '加载中...',
              processedText: '加载完成',
              failedText: '加载失败',
              noMoreText: '没有更多数据',
              showText: true,
              messageText: '更新于 %T',
              showMessage: true,
            ),
            onRefresh: _onRefresh,
            onLoad: _onLoad,
            child: ListView.builder(
              controller: _scrollController,
              itemCount: momentList.length,
              itemBuilder: (context, index) {
                return MomentCard(moment: momentList[index]);
              },
            ),
          ),
        ),

        // 返回顶部按钮
        if (_showScrollToTop)
          Positioned(
            right: 10,
            bottom: 20,
            child: FloatingActionButton(
              onPressed: _scrollToTop,
              backgroundColor: Colors.white,
              elevation: 5,
              mini: true,
              child: const Icon(
                Icons.arrow_upward
              ),
            ),
          ),
      ],
    );
  }
}