import time
from typing import Optional, List, Dict, Any
import time
from typing import List, Dict, Any, Optional

class ReplyBuilder:
    """
    原生微信消息回复构建器 (Native WeChat Reply Builder)
    
    功能：
    1. 生成所有标准类型的被动回复 XML (明文)。
    2. 自动处理 ToUserName/FromUserName 的反转。
    3. 支持文本、图片、语音、视频、音乐、图文、客服转发。
    
    注意：
    - 返回的是明文字符串。如果公众号开启了加密模式，需在主程序中对返回结果进行 AES 加密。
    - 所有 media_id 必须是通过微信接口上传后获得的有效 ID。
    """

    @staticmethod
    def _get_base_xml(to_user: str, from_user: str, create_time: int, msg_type: str) -> str:
        """生成公共的 XML 头部"""
        return f"""<xml>
<ToUserName><![CDATA[{to_user}]]></ToUserName>
<FromUserName><![CDATA[{from_user}]]></FromUserName>
<CreateTime>{create_time}</CreateTime>
<MsgType><![CDATA[{msg_type}]]></MsgType>
"""

    @staticmethod
    def text(msg: Dict[str, Any], content: str) -> str:
        """
        构造文本回复
        :param msg: 原始接收消息字典
        :param content: 回复的文本内容
        """
        to_user = msg.get('FromUserName')
        from_user = msg.get('ToUserName')
        create_time = int(time.time())

        xml = ReplyBuilder._get_base_xml(to_user, from_user, create_time, 'text')
        xml += f"<Content><![CDATA[{content}]]></Content>\n</xml>"
        return xml

    @staticmethod
    def image(msg: Dict[str, Any], media_id: str) -> str:
        """
        构造图片回复
        :param msg: 原始接收消息字典
        :param media_id: 微信服务器返回的图片媒体 ID
        """
        to_user = msg.get('FromUserName')
        from_user = msg.get('ToUserName')
        create_time = int(time.time())

        xml = ReplyBuilder._get_base_xml(to_user, from_user, create_time, 'image')
        xml += f"""<Image>
<MediaId><![CDATA[{media_id}]]></MediaId>
</Image>
</xml>"""
        return xml

    @staticmethod
    def voice(msg: Dict[str, Any], media_id: str) -> str:
        """
        构造语音回复
        :param msg: 原始接收消息字典
        :param media_id: 微信服务器返回的语音媒体 ID
        """
        to_user = msg.get('FromUserName')
        from_user = msg.get('ToUserName')
        create_time = int(time.time())

        xml = ReplyBuilder._get_base_xml(to_user, from_user, create_time, 'voice')
        xml += f"""<Voice>
<MediaId><![CDATA[{media_id}]]></MediaId>
</Voice>
</xml>"""
        return xml

    @staticmethod
    def video(msg: Dict[str, Any], media_id: str, title: str = "", description: str = "") -> str:
        """
        构造视频回复
        :param msg: 原始接收消息字典
        :param media_id: 微信服务器返回的视频媒体 ID
        :param title: 视频标题 (可选，建议填写)
        :param description: 视频描述 (可选)
        """
        to_user = msg.get('FromUserName')
        from_user = msg.get('ToUserName')
        create_time = int(time.time())

        xml = ReplyBuilder._get_base_xml(to_user, from_user, create_time, 'video')
        xml += f"""<Video>
<MediaId><![CDATA[{media_id}]]></MediaId>
<Title><![CDATA[{title}]]></Title>
<Description><![CDATA[{description}]]></Description>
</Video>
</xml>"""
        return xml

    @staticmethod
    def music(msg: Dict[str, Any], title: str, description: str, music_url: str, hq_music_url: str, thumb_media_id: str) -> str:
        """
        构造音乐回复
        :param msg: 原始接收消息字典
        :param title: 音乐标题
        :param description: 音乐描述
        :param music_url: 音乐播放链接 (普通质量，http/https)
        :param hq_music_url: 音乐播放链接 (高质量，http/https)
        :param thumb_media_id: 封面图的媒体 ID (必须已上传到微信)
        """
        to_user = msg.get('FromUserName')
        from_user = msg.get('ToUserName')
        create_time = int(time.time())

        xml = ReplyBuilder._get_base_xml(to_user, from_user, create_time, 'music')
        xml += f"""<Music>
<Title><![CDATA[{title}]]></Title>
<Description><![CDATA[{description}]]></Description>
<MusicUrl><![CDATA[{music_url}]]></MusicUrl>
<HQMusicUrl><![CDATA[{hq_music_url}]]></HQMusicUrl>
<ThumbMediaId><![CDATA[{thumb_media_id}]]></ThumbMediaId>
</Music>
</xml>"""
        return xml

    @staticmethod
    def news(msg: Dict[str, Any], articles: List[Dict[str, str]]) -> str:
        """
        构造图文消息回复 (支持 1-8 篇)
        :param msg: 原始接收消息字典
        :param articles: 文章列表，每项包含 title, description, image, url
        """
        to_user = msg.get('FromUserName')
        from_user = msg.get('ToUserName')
        create_time = int(time.time())
        
        if not articles:
            # 如果没有文章，返回空字符串或默认文本，避免生成非法 XML
            return ""
        
        count = len(articles)
        if count > 8:
            count = 8
            articles = articles[:8]

        xml = ReplyBuilder._get_base_xml(to_user, from_user, create_time, 'news')
        xml += f"<ArticleCount>{count}</ArticleCount>\n<Articles>\n"

        for item in articles:
            title = item.get('title', '无标题')
            desc = item.get('description', '')
            img_url = item.get('image', '')
            link_url = item.get('url', '#')
            
            xml += f"""<item>
<Title><![CDATA[{title}]]></Title>
<Description><![CDATA[{desc}]]></Description>
<PicUrl><![CDATA[{img_url}]]></PicUrl>
<Url><![CDATA[{link_url}]]></Url>
</item>\n"""

        xml += "</Articles>\n</xml>"
        return xml

    @staticmethod
    def single_article(msg: Dict[str, Any], title: str, description: str, image: str, url: str) -> str:
        """
        快捷方法：构造单篇图文消息
        """
        article = {
            "title": title,
            "description": description,
            "image": image,
            "url": url
        }
        return ReplyBuilder.news(msg, [article])

    @staticmethod
    def transfer_customer_service(msg: Dict[str, Any]) -> str:
        """
        构造转发客服消息指令
        用途：当机器人无法回答时，将此消息返回给微信，用户消息会进入客服队列，
             由人工客服或多客服系统接管。
        :param msg: 原始接收消息字典
        """
        to_user = msg.get('FromUserName')
        from_user = msg.get('ToUserName')
        create_time = int(time.time())

        # 这种类型的回复没有 Content 或其他节点，只有 MsgType
        xml = f"""<xml>
<ToUserName><![CDATA[{to_user}]]></ToUserName>
<FromUserName><![CDATA[{from_user}]]></FromUserName>
<CreateTime>{create_time}</CreateTime>
<MsgType><![CDATA[transfer_customer_service]]></MsgType>
</xml>"""
        return xml