#!/usr/bin/env python
"""从群消息派生 group_member（发言者=成员）。

云客 API 不单独给群成员列表（chatroom payload 的 memberIds 我们抓不到，
2026-08-20 确认），但群消息的 talker 就是发言成员的 wxid、sender_name 是其
群昵称——368k 群消息足够派生出高质量成员表（覆盖所有发过言的成员）。

昵称取该成员在群里最新一条消息的 sender_name（SQLite 的 max()+裸列行为，
取 max(timestamp) 同行的值）。幂等可重跑；建议在 group-messages 之后执行。

用法:
    cd yunke-server && DB_URL="sqlite+aiosqlite:///./smoke.db" \
      .venv/Scripts/python.exe -m scripts.backfill_group_members
"""
from __future__ import annotations

import asyncio
import logging

from sqlalchemy import text as sa_text

from app.db.base import async_engine, async_session_maker
from app.db.models import GroupMember
from app.storage.repos import _upsert_one

logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(message)s")
log = logging.getLogger("backfill_group_members")

# row_number() 窗口取 timestamp 最新一行的 sender_name：MySQL 8 的
# only_full_group_by 拒绝 SQLite 式「max()+裸列」(1055)，窗口写法两库通用
# 且语义严格（最新一条的昵称），不依赖方言碰巧行为
SQL = sa_text("""
SELECT room_id, talker_id, sender_name, last_ts, msg_count
FROM (
  SELECT room_id, talker_id, sender_name, timestamp AS last_ts,
         count(*) OVER (PARTITION BY room_id, talker_id) AS msg_count,
         row_number() OVER (
           PARTITION BY room_id, talker_id ORDER BY timestamp DESC
         ) AS rn
  FROM message
  WHERE channel = 'wechat' AND room_id IS NOT NULL AND room_id != ''
    AND talker_id IS NOT NULL AND talker_id != ''
) t
WHERE rn = 1
""")


async def main() -> None:
    async with async_engine.connect() as conn:
        rows = (await conn.execute(SQL)).fetchall()
    log.info(f"派生出 {len(rows)} 个 (群, 成员) 对")

    async with async_session_maker() as session:
        for room_id, talker_id, sender_name, last_ts, msg_count in rows:
            await _upsert_one(session, GroupMember, {
                "channel": "wechat",
                "room_id": room_id,
                "member_id": talker_id,
                "nickname": sender_name,
                # raw_json 附加派生统计，抽屉可见
                "raw_json": {
                    "derived_from": "group_messages",
                    "msg_count": msg_count,
                    "last_msg_ts": last_ts,
                },
            })
        await session.commit()
    log.info(f"DONE: group_member upserted={len(rows)}")


if __name__ == "__main__":
    asyncio.run(main())