"""微信服务号模板消息：OA 审批/抄送通知。"""
from __future__ import annotations

import logging
from typing import Any, Dict

import httpx

from app.core.config import settings
from app.services.wechat_mp_auth import WechatMpAuthError, get_mp_access_token

logger = logging.getLogger(__name__)

_WX_TEMPLATE_SEND = "https://api.weixin.qq.com/cgi-bin/message/template/send"

# 微信 thing 类字段建议约 20 汉字；按字符保守截断
_THING_MAX_CHARS = 20


def _truncate_thing(value: str, max_chars: int = _THING_MAX_CHARS) -> str:
    s = (value or "").strip()
    if len(s) <= max_chars:
        return s
    return s[:max_chars]


def _build_oa_data(
    *,
    title: str,
    applicant: str,
    node_name: str,
    time_text: str,
) -> Dict[str, Dict[str, str]]:
    return {
        settings.WX_MP_TPL_FIELD_TITLE: {"value": _truncate_thing(title)},
        settings.WX_MP_TPL_FIELD_APPLICANT: {"value": _truncate_thing(applicant)},
        settings.WX_MP_TPL_FIELD_NODE: {"value": _truncate_thing(node_name)},
        settings.WX_MP_TPL_FIELD_TIME: {"value": (time_text or "").strip()},
    }


def _send_template(
    *,
    mp_openid: str,
    template_id: str,
    data: Dict[str, Any],
    pagepath: str,
) -> Dict[str, Any]:
    oid = (mp_openid or "").strip()
    if not oid:
        return {"success": False, "error": "missing_mp_openid"}

    tid = (template_id or "").strip()
    if not tid:
        return {"success": False, "error": "missing_template_id"}

    mini_appid = (settings.WXPAY_MINI_APPID or "").strip()
    if not mini_appid:
        return {"success": False, "error": "missing_mini_appid"}

    try:
        access_token = get_mp_access_token()
    except WechatMpAuthError as exc:
        logger.warning("mp template send aborted: %s", exc)
        return {"success": False, "error": str(exc)}

    payload = {
        "touser": oid,
        "template_id": tid,
        "data": data,
        "miniprogram": {
            "appid": mini_appid,
            "pagepath": (pagepath or "").lstrip("/"),
        },
    }

    try:
        with httpx.Client(timeout=15.0) as client:
            r = client.post(
                f"{_WX_TEMPLATE_SEND}?access_token={access_token}",
                json=payload,
            )
            r.raise_for_status()
            result = r.json()
    except Exception as exc:
        logger.exception("mp template send request failed")
        return {"success": False, "error": str(exc)}

    if result.get("errcode") in (0, None):
        logger.info(
            "mp template send ok: openid=%s msgid=%s",
            oid,
            result.get("msgid"),
        )
        return {"success": True, "msgid": result.get("msgid")}

    logger.error("mp template send failed: %s", result)
    return {
        "success": False,
        "error": result.get("errmsg") or "send_failed",
        "errcode": result.get("errcode"),
    }


def send_oa_approval_notify(
    *,
    mp_openid: str,
    pagepath: str,
    title: str,
    applicant: str,
    node_name: str,
    time_text: str,
) -> dict:
    return _send_template(
        mp_openid=mp_openid,
        template_id=settings.WX_MP_TEMPLATE_APPROVAL,
        data=_build_oa_data(
            title=title,
            applicant=applicant,
            node_name=node_name,
            time_text=time_text,
        ),
        pagepath=pagepath,
    )


def send_oa_cc_notify(
    *,
    mp_openid: str,
    pagepath: str,
    title: str,
    applicant: str,
    node_name: str,
    time_text: str,
) -> dict:
    return _send_template(
        mp_openid=mp_openid,
        template_id=settings.WX_MP_TEMPLATE_CC,
        data=_build_oa_data(
            title=title,
            applicant=applicant,
            node_name=node_name,
            time_text=time_text,
        ),
        pagepath=pagepath,
    )