"""ai_trade heartbeat — NAS Redis로 worker:ai_trade:heartbeat SET.

Global Constraints 계약 1: kind=trader, state=market_open|market_closed.
ai_trade는 Windows 호스트 실행이라 _shared import 경로가 달라 자체 미니 헬퍼로 둔다.
"""
from __future__ import annotations

import asyncio
import datetime as dt
import json
import logging
import os

import redis.asyncio as aioredis

logger = logging.getLogger(__name__)

REDIS_URL = os.getenv("REDIS_URL", "redis://192.168.45.54:6379")
KEY = "worker:ai_trade:heartbeat"
INTERVAL = int(os.getenv("HEARTBEAT_INTERVAL", "15"))
TTL = int(os.getenv("HEARTBEAT_TTL", "45"))


def build_trader_payload(state: str, signals: int = 0) -> str:
    """JSON 문자열 반환. state: 'market_open' | 'market_closed'."""
    return json.dumps({
        "name": "ai_trade",
        "kind": "trader",
        "state": state,
        "ts": dt.datetime.now(dt.timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ"),
        "last_job_at": None,
        "jobs_done": signals,
        "jobs_failed": 0,
    })


async def heartbeat_loop(state_fn) -> None:
    """Redis에 HEARTBEAT_INTERVAL마다 SET EX TTL.

    Args:
        state_fn: () -> (state: str, signals: int). 호출자가 폴링 윈도우 판정 주입.
    """
    redis = aioredis.from_url(REDIS_URL, decode_responses=False)
    try:
        while True:
            try:
                state, signals = state_fn()
                payload = build_trader_payload(state, signals)
                await redis.set(KEY, payload, ex=TTL)
                logger.debug("ai_trade heartbeat sent: state=%s signals=%d", state, signals)
            except asyncio.CancelledError:
                raise
            except Exception:
                logger.exception("ai_trade heartbeat 실패 — 다음 주기에 재시도")
            await asyncio.sleep(INTERVAL)
    finally:
        await redis.aclose()