import xml.etree.ElementTree as ET
import html


def format_quote_message(xml_content):
    """
    格式化引用消息
    
    Args:
        xml_content: XML格式的消息内容
        
    Returns:
        格式化后的消息文本
    """
    try:
        # 解析XML
        root = ET.fromstring(xml_content)

        # 获取主消息内容
        title_elem = root.find('.//title')
        main_content = title_elem.text if title_elem is not None else ""

        # 获取引用消息信息
        refer_msg = root.find('.//refermsg')
        if refer_msg is not None:
            display_name = refer_msg.find('displayname').text if refer_msg.find('displayname') is not None else "未知用户"
            quoted_content = refer_msg.find('content').text if refer_msg.find('content') is not None else ""

            # 解码HTML实体
            quoted_content = html.unescape(quoted_content)

            # 构建格式化的引用消息
            formatted_message = f"┌─────────────────────────────────\n│ 引用 {display_name}：{quoted_content}\n└─────────────────────────────────\n{main_content}"
            return formatted_message

        return main_content
    except Exception as e:
        return f"解析引用消息失败: {str(e)}"