"""
企微 XML/字段解析 → InboundMessage。

本文件职责：从解密后的明文抽出 sender_id / message_id / content。
禁止：无 sender_id 时仍组装「可入业务」消息（调用方应丢弃）；禁止再请求企微 userid。
"""

from __future__ import annotations

import xml.etree.ElementTree as ET
from typing import Mapping

from agent.channel.wecom.models import InboundMessage


def _text(root: ET.Element, tag: str) -> str:
    node = root.find(tag)
    if node is None or node.text is None:
        return ""
    return node.text.strip()


def parse_plain_xml(xml_text: str, *, default_agent_id: str = "") -> InboundMessage:
    """
    解析企微回调明文 XML。

    调用时机：验签解密成功后、入 inbox 前。
    返回：InboundMessage；MsgType 非 text 时 content 可能为空，由 handler 决定是否忽略。
    """
    root = ET.fromstring(xml_text)
    msg_type = _text(root, "MsgType") or "unknown"
    sender_id = _text(root, "FromUserName")
    msg_id = _text(root, "MsgId") or _text(root, "MsgID")
    create_time_raw = _text(root, "CreateTime")
    create_time = int(create_time_raw) if create_time_raw.isdigit() else 0
    agent_id = _text(root, "AgentID") or _text(root, "AgentId") or default_agent_id
    content = _text(root, "Content") if msg_type == "text" else ""
    # 事件类可带 Event Key；骨架阶段仅记 raw，不进 Graph
    event = _text(root, "Event")
    if not msg_id:
        # 无 MsgId（如部分事件）时用发送人+时间拼幂等键，避免空键撞车
        msg_id = f"{sender_id}:{create_time}:{msg_type}:{event}"

    chat_type = "single"
    chat_id = ""
    # 企业微信群聊应用消息偶发带 ChatId；无则保持私聊语义
    chat_id = _text(root, "ChatId") or _text(root, "ChatID")
    if chat_id:
        chat_type = "group"

    return InboundMessage(
        sender_id=sender_id,
        message_id=msg_id,
        content=content,
        msg_type=msg_type,
        chat_id=chat_id,
        chat_type=chat_type,
        agent_id=agent_id,
        create_time=create_time,
        media={},
        raw={"event": event, "xml": xml_text},
    )


def inbound_from_inject(payload: Mapping[str, object], *, default_agent_id: str = "") -> InboundMessage:
    """
    本机联调注入：不经企微密文，直接构造 InboundMessage。

    用途：并存期公网回调仍进现网时，用 POST /internal/dev/inject-text 测出站回复。
    约束：必须带 sender_id（企微 userid），否则不得入队。
    """
    sender_id = str(payload.get("sender_id") or "").strip()
    content = str(payload.get("content") or "").strip()
    message_id = str(payload.get("message_id") or "").strip()
    if not message_id:
        message_id = f"inject:{sender_id}:{int(payload.get('create_time') or 0)}:{hash(content) & 0xFFFFFFFF}"
    return InboundMessage(
        sender_id=sender_id,
        message_id=message_id,
        content=content,
        msg_type="text",
        chat_type="single",
        agent_id=str(payload.get("agent_id") or default_agent_id),
        create_time=int(payload.get("create_time") or 0),
        raw={"source": "dev_inject"},
    )