"""命令监听处理器：匹配 #命令名 格式的消息，转发到外部回调 URL 并自动回复。"""

import re

import aiohttp

from ..config import UPLOAD_DIR, command
from ..handlers.message import _resolve_url


def build_command_pattern() -> re.Pattern:
    """构建命令匹配正则：# + N个字符（中文/数字/字母/下划线等），后面可跟空格+内容或无内容。

    每个"字符"按 Unicode 码点计：
    - 一个中文字 = 1
    - 一个数字 = 1
    - 一个英文字母 = 1
    - 其他非空白字符 = 1
    """
    return re.compile(
        rf"^{re.escape(command.prefix)}(\S{{{command.length_min},{command.length_max}}})(?:\s+(.+))?$",
        re.DOTALL,
    )


COMMAND_PATTERN = build_command_pattern()


def rebuild_pattern() -> None:
    """动态配置变更后重新编译正则。"""
    global COMMAND_PATTERN
    COMMAND_PATTERN = build_command_pattern()


def parse_command(raw_message: str) -> dict | None:
    """解析消息，匹配命令模式。返回 {command, content, raw_message} 或 None。"""
    match = COMMAND_PATTERN.match(raw_message.strip())
    if not match:
        return None
    return {
        "command": match.group(1),
        "content": match.group(2).strip() if match.group(2) else "",
        "raw_message": raw_message.strip(),
    }


async def send_command_callback(data: dict, event, api, logger) -> None:
    """将命令数据 POST 到外部回调 URL，根据响应自动回复到 QQ。

    回调服务器返回格式：
    {
        "reply": "回复文本",                    // 纯文本回复（引用原消息）
        "messages": [                          // 批量回复（可选，优先于 reply）
            {"type": "text", "msg": "..."},
            {"type": "image", "url": "..."},
            {"type": "file", "url": "..."},
            {"type": "video", "url": "..."}
        ],
        "at_sender": true                      // 是否 @发送者（默认取配置，仅群聊）
    }

    所有字段均为可选，无回复内容时返回空 JSON 即可。
    回复会引用触发命令的原消息。
    """
    if not command.callback_url:
        logger.warning("callback_url 未配置，跳过命令回调")
        return

    try:
        async with aiohttp.ClientSession() as session:
            async with session.post(
                command.callback_url,
                json=data,
                timeout=aiohttp.ClientTimeout(total=command.callback_timeout),
            ) as resp:
                if resp.status >= 400:
                    body = await resp.text()
                    logger.error(
                        "命令回调失败: status=%d url=%s body=%s",
                        resp.status, command.callback_url, body[:200],
                    )
                    return

                # 解析响应，自动回复
                try:
                    result = await resp.json(content_type=None)
                except Exception:
                    return

                if not isinstance(result, dict):
                    return

                await _handle_reply(result, event.data, api, logger)

    except Exception as exc:
        logger.error("命令回调异常: url=%s error=%s", command.callback_url, exc)


async def _handle_reply(result: dict, msg_event, api, logger) -> None:
    """处理回调响应，引用原消息自动回复。msg_event 是 GroupMessageEvent / PrivateMessageEvent。"""
    # at_sender: 回调响应中的值优先，未指定则使用全局配置
    at_sender = result.get("at_sender", command.at_sender)
    messages = result.get("messages")
    reply = result.get("reply")
    group_id = getattr(msg_event, "group_id", None)
    user_id = msg_event.user_id
    message_id = msg_event.message_id

    # 构造引用消息段
    from ncatbot.types import MessageArray, Reply

    def build_reply_msg(text=None, image=None, video=None) -> MessageArray:
        """构建带引用的消息段。"""
        msg = MessageArray()
        msg.add_reply(message_id)
        if group_id and at_sender:
            msg.add_at(user_id)
            msg.add_text(" ")
        if text is not None:
            msg.add_text(text)
        if image is not None:
            msg.add_image(image)
        if video is not None:
            msg.add_video(video)
        return msg

    # 批量回复：引用 + 批量消息段
    if messages and isinstance(messages, list):
        text_parts: list[str] = []
        image_url: str | None = None
        video_url: str | None = None
        file_msgs: list[dict] = []

        for msg in messages:
            msg_type = msg.get("type", "text")
            if msg_type == "text":
                text_parts.append(msg.get("msg", ""))
            elif msg_type == "image":
                image_url = _resolve_url(msg.get("url", ""))
            elif msg_type == "video":
                video_url = _resolve_url(msg.get("url", ""))
            elif msg_type == "file":
                file_msgs.append(msg)

        text = "\n".join(text_parts) if text_parts else None

        try:
            # 组合消息（带引用）
            if text or image_url or video_url:
                reply_msg = build_reply_msg(text=text, image=image_url, video=video_url)
                if group_id:
                    await api.qq.post_group_array_msg(group_id=group_id, msg=reply_msg)
                else:
                    await api.qq.post_private_array_msg(user_id=user_id, msg=reply_msg)
            # 文件单独发
            for fm in file_msgs:
                url = _resolve_url(fm.get("url", ""))
                filename = url.split("/")[-1]
                if group_id:
                    await api.qq.send_group_file(group_id=group_id, file=url, name=filename)
                else:
                    await api.qq.send_private_file(user_id=user_id, file=url, name=filename)
        except Exception as exc:
            logger.error("命令回复失败: %s", exc)
        return

    # 纯文本回复：引用原消息
    if reply and isinstance(reply, str):
        try:
            reply_msg = build_reply_msg(text=reply)
            if group_id:
                await api.qq.post_group_array_msg(group_id=group_id, msg=reply_msg)
            else:
                await api.qq.post_private_array_msg(user_id=user_id, msg=reply_msg)
        except Exception as exc:
            logger.error("命令回复失败: %s", exc)