import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../pages/full_screen.dart';
import '../services/message_service.dart';
import 'chat/chat_window_content.dart';
import 'chat_floating_icon.dart';

class ChatPopup extends StatefulWidget {
  final double? iconSize;
  final Widget? icon;
  final Size chatSize;

  final ChatFloatingIcon? child;

  const ChatPopup({
    super.key,
    this.child,
    this.iconSize,
    this.icon,
    this.chatSize = const Size(320, 450),
  });

  @override
  State<ChatPopup> createState() => _ChatPopupState();
}

class _ChatPopupState extends State<ChatPopup> with SingleTickerProviderStateMixin {
  OverlayEntry? _overlayEntry;
  Offset _iconPosition = const Offset(10, 120);
  final double _iconSizeDefault = 80.0;
  late AnimationController _partScreenAnimationController;

  @override
  void initState() {
    super.initState();
    _partScreenAnimationController = AnimationController(
      duration: const Duration(milliseconds: 250),
      vsync: this,
    );
  }

  @override
  void dispose() {
    _removeOverlay();
    _partScreenAnimationController.dispose();
    super.dispose();
  }

  void _openFullScreen() async {
    final messageService = context.read<MessageService>();
    _removeOverlay();

    await Navigator.of(context).push(
      MaterialPageRoute(
        builder: (context) => ChangeNotifierProvider.value(
          value: messageService, // 传递同一个单例实例
          child: const FullScreenPage(),
        ),
      ),
    );
  }

  void _insertOverlay() {
    if (_overlayEntry != null) return;
    _overlayEntry = OverlayEntry(
      builder: (context) => _buildOverlayContent(),
    );
    Overlay.of(context).insert(_overlayEntry!);
    _partScreenAnimationController.forward();
  }

  void _removeOverlay() {
    if (_overlayEntry == null) return;
    _partScreenAnimationController.reverse().then((_) {
      _overlayEntry?.remove();
      _overlayEntry = null;
    });
  }

  Widget _buildOverlayContent() {
    return ChangeNotifierProvider.value(
      value: MessageService.instance,
      child: Material(
        color: Colors.transparent,
        child: LayoutBuilder(
          builder: (context, constraints) {
            final position = _calculatePosition(constraints);
            final double minHeight = constraints.maxHeight * 0.16;
            final double maxHeight = constraints.maxHeight * 0.4;
            final double chatWidth = constraints.maxWidth * 0.94;
            return Stack(
              children: [
                _buildPopupBackground(),
                Positioned(
                  left: position.left,
                  right: position.right,
                  bottom: position.bottom,
                  child: ChatWindowContent(
                    animationController: _partScreenAnimationController,
                    minHeight: minHeight,
                    maxHeight: maxHeight,
                    chatWidth: chatWidth,
                  ),
                ),
              ],
            );
          },
        ),
      ),
    );
  }

  Widget _buildPopupBackground() {
    return Positioned.fill(
      child: GestureDetector(
        onTap: () {
          final messageService = MessageService.instance;
          _removeOverlay();
          messageService.abortReply();
          messageService.initializeEmpty();
        },
        child: Container(
          color: Colors.black.withOpacity(0.1),
        ),
      ),
    );
  }

  Widget _buildFloatingIcon() {
    return ChatFloatingIcon(
      iconSize: widget.iconSize ?? _iconSizeDefault,
      icon: widget.icon,
      onLongPress: () async {
        final messageService = MessageService.instance;
        _insertOverlay();
        await messageService.startVoiceInput();
      },
      onLongPressUp: () async {
        final messageService = MessageService.instance;
        await messageService.stopAndProcessVoiceInput();
        final hasMessage = messageService.messages.isNotEmpty;
        if (!hasMessage) {
          _removeOverlay();
        }
      },
      onPositionChanged: (position) {
        setState(() {
          _iconPosition = position;
        });
        // 重新构建 overlay 以更新弹窗位置
        _overlayEntry?.markNeedsBuild();
      },
    );
  }

  // 计算PartScreen的位置，使其显示在FloatingIcon附近
  EdgeInsets _calculatePosition(BoxConstraints constraints) {
    final screenWidth = constraints.maxWidth;
    final screenHeight = constraints.maxHeight;
    final chatWidth = screenWidth * 0.94;
    final chatHeight = screenHeight * 0.4;

    // 1. 先将icon的right/bottom转为屏幕坐标（icon左下角）
    final iconLeft = screenWidth - _iconPosition.dx - (widget.iconSize ?? _iconSizeDefault);
    final iconBottom = _iconPosition.dy;
    final iconTop = iconBottom + (widget.iconSize ?? _iconSizeDefault);
    final iconCenterX = iconLeft + (widget.iconSize ?? _iconSizeDefault) / 2;

    // 判断FloatingIcon在屏幕的哪一边
    final isOnRightSide = iconCenterX > screenWidth / 2;

    // 计算水平位置
    double leftPadding;
    if (isOnRightSide) {
      // 图标在右边，聊天框显示在左边
      leftPadding = (screenWidth - chatWidth) * 0.1;
    } else {
      // 图标在左边，聊天框显示在右边
      leftPadding = screenWidth - chatWidth - (screenWidth - chatWidth) * 0.1;
    }

    // 优先尝试放在icon上方
    double chatBottom = iconTop + 12; // 聊天框底部距离icon顶部12px
    double chatTop = screenHeight - chatBottom - chatHeight;

    // 如果上方空间不足，则放在icon下方
    if (chatTop < 0) {
      chatBottom = iconBottom - 12 - chatHeight / 2; // 聊天框顶部距离icon底部12px
      // 如果下方也不足，则贴底
      if (chatBottom < 0) {
        chatBottom = 20; // 距离底部20px
      }
    }

    return EdgeInsets.only(
      left: leftPadding,
      right: screenWidth - leftPadding - chatWidth,
      bottom: chatBottom,
    );
  }

  @override
  Widget build(BuildContext context) {
    // 只渲染 FloatingIcon，Overlay 弹窗内容在长按时插入
    return _buildFloatingIcon();
  }
}