import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:yumi/shared/business_logic/models/res/login_res.dart';
import 'package:provider/provider.dart';

import 'package:yumi/app_localizations.dart';
import 'package:yumi/app/constants/sc_screen.dart';
import 'package:yumi/services/audio/rtm_manager.dart';
import 'package:yumi/ui_kit/widgets/room/room_msg_item.dart';

class GiftChatPage extends StatefulWidget {
  @override
  _GiftChatPageState createState() => _GiftChatPageState();
}

class _GiftChatPageState extends State<GiftChatPage> {
  ScrollController _controller = ScrollController();
  bool showGoBottom = true;
  bool _isDisposed = false;
  List<Msg> _msgList = [];
  late RtmProvider provider;

  @override
  void initState() {
    super.initState();
    _controller.addListener(_scrollListener);
    provider = Provider.of<RtmProvider>(context, listen: false);
    var msgList = provider.roomGiftMsgList;
    provider.msgGiftListener = _onNewMsg;
    _msgList.addAll(msgList ??= []);
    // 使用安全的方式初始化滚动位置
    _initScrollPosition();
  }

  void _scrollListener() {
    final position = _controller.position;

    // 容差范围（5像素）避免精度问题
    const tolerance = 10.0;

    // 判断是否在第一个项目（颠倒列表的底部）
    final isAtBottom = position.pixels < position.minScrollExtent + tolerance;

    // 判断是否在最后一个项目（颠倒列表的顶部）
    // final isAtTop = position.pixels >= position.maxScrollExtent - tolerance;
    if (isAtBottom != showGoBottom) {
      showGoBottom = isAtBottom;
      if (!_isDisposed) {
        setState(() {});
      }
    }
  }

  // 安全初始化滚动位置
  void _initScrollPosition() {
    WidgetsBinding.instance.addPostFrameCallback((timeStamp) async {
      if (_isDisposed) return;
      _controller.jumpTo(0.0);
    });
  }

  _onNewMsg(Msg msg) {
    if (_isDisposed) return; // 如果组件已销毁，直接返回
    if (msg.groupId == "-1000") {
      ///清屏
      _msgList.clear();
      setState(() {});
      return;
    }
    if (!_msgList.contains(msg)) {
      setState(() {
        _msgList.insert(0, msg);
      });
      _controller.jumpTo(0.0);
    }
  }

  @override
  void dispose() {
    _isDisposed = true;
    provider.msgGiftListener = null;
    _controller.removeListener(_scrollListener);
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.transparent,
      resizeToAvoidBottomInset: false,
      body: Stack(
        alignment: Alignment.bottomLeft,
        children: [
          ListView.builder(
            reverse: true,
            controller: _controller,
            shrinkWrap: true,
            itemBuilder: (BuildContext context, int index) {
              return MsgItem(
                msg: _msgList[index],
                onClick: (SocialChatUserProfile? user) {},
              );
            },
            itemCount: _msgList.length,
          ),
          Visibility(
            visible: !showGoBottom,
            child: GestureDetector(
              onTap: () {
                if (_controller.hasClients) {
                  _controller.jumpTo(0.0);
                }
              },
              child: Container(
                margin: EdgeInsets.symmetric(horizontal: width(15)),
                padding: EdgeInsets.symmetric(horizontal: 10.w, vertical: 4.w),
                decoration: BoxDecoration(
                  borderRadius: BorderRadius.circular(52),
                  color: Colors.white,
                ),
                child: Row(
                  mainAxisSize: MainAxisSize.min,
                  children: <Widget>[
                    Text(
                      SCAppLocalizations.of(context)!.scrollToTheBottom,
                      style: TextStyle(fontSize: 10.sp),
                    ),
                    SizedBox(width: 4.w),
                    Icon(Icons.chevron_right, size: 10.w),
                  ],
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }
}