import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:im_flutter_sdk/im_flutter_sdk.dart';

import '../../../generated/assets.dart';

class MessageItem extends StatelessWidget {
  final EMMessage message;
  final bool isSentByMe;
  final EMMessage? previousMessage;

  const MessageItem({
    required this.message,
    required this.isSentByMe,
    this.previousMessage,
    super.key,
  });

  @override
  Widget build(BuildContext context) {
    // 只处理文本消息，其他类型消息可以根据需要扩展
    if (message.body.type == MessageType.TXT) {
      final textBody = message.body as EMTextMessageBody;
      return Column(
        children: [
          // 显示时间（如果距离上一条消息超过20分钟）
          if (shouldShowTime()) _buildTimeLabel(),
          Container(
            padding: EdgeInsets.symmetric(
              horizontal: 16.w,
              vertical: 8.h,
            ),
            child: Row(
              mainAxisAlignment: isSentByMe ? MainAxisAlignment.end : MainAxisAlignment.start,
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                if (!isSentByMe) _buildAvatar(),
                if (!isSentByMe) SizedBox(width: 8.w),
                Container(
                  constraints: BoxConstraints(maxWidth: 240.w),
                  margin: EdgeInsets.only(top: 10.h),
                  padding: EdgeInsets.symmetric(
                    horizontal: 12.w,
                    vertical: 8.h,
                  ),
                  decoration: BoxDecoration(
                    color: isSentByMe ? Color(0xff8E7BF6) : Colors.white, // 修改为紫色和白色
                    borderRadius: BorderRadius.only(
                      topLeft: isSentByMe ? Radius.circular(12.w) : Radius.circular(0),
                      topRight: isSentByMe ? Radius.circular(0) : Radius.circular(12.w),
                      bottomLeft: Radius.circular(12.w),
                      bottomRight: Radius.circular(0),
                    ),
                  ),
                  child: Text(
                    textBody.content,
                    style: TextStyle(
                      fontSize: 14.sp,
                      color: isSentByMe ? Colors.white : Colors.black, // 发送方白色文字，接收方黑色文字
                    ),
                  ),
                ),
                if (isSentByMe) SizedBox(width: 8.w),
                if (isSentByMe) _buildAvatar(),
              ],
            ),
          ),
        ],
      );
    }
    
    // 非文本消息显示占位符
    return Column(
      children: [
        if (shouldShowTime()) _buildTimeLabel(),
        Container(
          padding: EdgeInsets.symmetric(
            horizontal: 16.w,
            vertical: 8.h,
          ),
          child: Text('不支持的消息类型'),
        ),
      ],
    );
  }

  // 判断是否需要显示时间
  bool shouldShowTime() {
    if (previousMessage == null) {
      return true; // 第一条消息显示时间
    }
    
    // 判断距离上一条消息是否超过20分钟（1200000毫秒）
    return (message.serverTime - previousMessage!.serverTime) > 1200000;
  }

  // 构建时间标签
  Widget _buildTimeLabel() {
    final formattedTime = formatMessageTime(message.serverTime);
    
    return Container(
      alignment: Alignment.center,
      padding: EdgeInsets.symmetric(
        horizontal: 16.w,
      ),
      child: Container(
        padding: EdgeInsets.symmetric(
          horizontal: 12.w,
        ),
        child: Text(
          formattedTime,
          style: TextStyle(
            fontSize: 12.sp,
            color: Colors.grey,
          ),
        ),
      ),
    );
  }

  // 格式化消息时间
  String formatMessageTime(int timestamp) {
    final date = DateTime.fromMillisecondsSinceEpoch(timestamp);
    final now = DateTime.now();
    final today = DateTime(now.year, now.month, now.day);
    final yesterday = DateTime(now.year, now.month, now.day - 1);
    final messageDate = DateTime(date.year, date.month, date.day);
    
    if (messageDate.isAtSameMomentAs(today)) {
      // 今天的消息显示时间
      return '今天 ${date.hour.toString().padLeft(2, '0')}:${date.minute.toString().padLeft(2, '0')}';
    } else if (messageDate.isAtSameMomentAs(yesterday)) {
      // 昨天的消息
      return '昨天 ${date.hour.toString().padLeft(2, '0')}:${date.minute.toString().padLeft(2, '0')}';
    } else {
      // 其他日期显示完整日期和时间
      return '${date.month}月${date.day}日 ${date.hour.toString().padLeft(2, '0')}:${date.minute.toString().padLeft(2, '0')}';
    }
  }

  // 构建头像
  Widget _buildAvatar() {
    return Container(
      width: 40.w,
      height: 40.w,
      decoration: BoxDecoration(
        borderRadius: BorderRadius.circular(20.w),
        image: DecorationImage(
          image: AssetImage(Assets.imagesAvatarsExample),
          fit: BoxFit.cover,
        ),
      ),
    );
  }
}