"""한국투자증권 KIS OpenAPI - READ ONLY 시세 조회.

본 모듈은 주문/체결/잔고변경 endpoint를 일절 import 하지 않는다.
사용하는 endpoint:
  - POST /oauth2/tokenP                              : 토큰 발급
  - GET  /uapi/domestic-stock/v1/quotations/inquire-daily-itemchartprice
                                                     : 일/주/월봉 시세 조회 (read-only)
  - GET  /uapi/domestic-stock/v1/quotations/inquire-price
                                                     : 현재가 조회 (read-only)

키 누락 시 모든 함수는 SkippedMissingKey 예외로 빠르게 실패하므로 호출 측에서 잡아서
status='skipped_missing_key' 처리.
"""
from __future__ import annotations

import logging
import threading
import time
from dataclasses import dataclass
from datetime import date, datetime
from typing import Any

import httpx
from tenacity import retry, retry_if_exception_type, stop_after_attempt, wait_exponential

from app.config import settings

logger = logging.getLogger(__name__)

KIS_BASE = "https://openapi.koreainvestment.com:9443"
USER_AGENT = "stock_chart_site/0.1 (+personal)"


class SkippedMissingKey(RuntimeError):
    """KIS 키 미설정 시 발생. 호출 측에서 skipped 로 매핑."""


@dataclass
class _Token:
    value: str
    expires_at: float          # epoch seconds


_token_cache: _Token | None = None
_token_lock = threading.Lock()


def _has_keys() -> bool:
    return bool(settings.kis_app_key and settings.kis_app_secret)


@retry(
    stop=stop_after_attempt(3),
    wait=wait_exponential(multiplier=1, min=1, max=8),
    retry=retry_if_exception_type((httpx.HTTPError, httpx.TimeoutException)),
    reraise=True,
)
def _issue_token() -> _Token:
    if not _has_keys():
        raise SkippedMissingKey("kis app_key/secret missing")
    url = f"{KIS_BASE}/oauth2/tokenP"
    body = {
        "grant_type": "client_credentials",
        "appkey": settings.kis_app_key,
        "appsecret": settings.kis_app_secret,
    }
    with httpx.Client(timeout=10.0, headers={"User-Agent": USER_AGENT}) as cli:
        resp = cli.post(url, json=body)
        resp.raise_for_status()
        data = resp.json()
    access = data["access_token"]
    # KIS 는 expires_in (sec) 와 access_token_token_expired (epoch-like str) 둘 다 줌
    expires_in = int(data.get("expires_in", 3600))
    return _Token(value=access, expires_at=time.time() + expires_in - 60)


def get_token() -> str:
    """캐시된 토큰 반환. 만료 60초 전부터 재발급. 키 없으면 SkippedMissingKey."""
    global _token_cache
    with _token_lock:
        if _token_cache and _token_cache.expires_at > time.time():
            return _token_cache.value
        _token_cache = _issue_token()
        logger.info("kis token issued, expires_at=%s", datetime.fromtimestamp(_token_cache.expires_at))
        return _token_cache.value


def _headers(tr_id: str) -> dict[str, str]:
    return {
        "Content-Type": "application/json; charset=utf-8",
        "Accept": "application/json",
        "User-Agent": USER_AGENT,
        "authorization": f"Bearer {get_token()}",
        "appkey": settings.kis_app_key or "",
        "appsecret": settings.kis_app_secret or "",
        "tr_id": tr_id,
        "custtype": "P",
    }


@retry(
    stop=stop_after_attempt(2),
    wait=wait_exponential(multiplier=1, min=1, max=4),
    retry=retry_if_exception_type((httpx.HTTPError, httpx.TimeoutException)),
    reraise=True,
)
def fetch_daily_price(
    code: str,
    start: date,
    end: date,
    *,
    period: str = "D",
    adjusted: bool = True,
) -> list[dict[str, Any]]:
    """일/주/월봉 시세 조회 (read-only).

    Returns: [{date, open, high, low, close, volume}, ...]
    """
    if not _has_keys():
        raise SkippedMissingKey("kis app_key/secret missing")
    url = f"{KIS_BASE}/uapi/domestic-stock/v1/quotations/inquire-daily-itemchartprice"
    params = {
        "FID_COND_MRKT_DIV_CODE": "J",        # J=주식
        "FID_INPUT_ISCD": code,
        "FID_INPUT_DATE_1": start.strftime("%Y%m%d"),
        "FID_INPUT_DATE_2": end.strftime("%Y%m%d"),
        "FID_PERIOD_DIV_CODE": period,        # D/W/M
        "FID_ORG_ADJ_PRC": "0" if adjusted else "1",
    }
    with httpx.Client(timeout=15.0) as cli:
        resp = cli.get(url, headers=_headers("FHKST03010100"), params=params)
        resp.raise_for_status()
        data = resp.json()
    if data.get("rt_cd") != "0":
        raise RuntimeError(f"kis error: {data.get('msg1')} (rt_cd={data.get('rt_cd')})")

    out: list[dict[str, Any]] = []
    for row in data.get("output2", []) or []:
        raw_date = row.get("stck_bsop_date")
        if not raw_date:
            continue
        try:
            day = datetime.strptime(raw_date, "%Y%m%d").date()
        except ValueError:
            continue
        out.append(
            {
                "date": day,
                "open": float(row.get("stck_oprc") or 0),
                "high": float(row.get("stck_hgpr") or 0),
                "low": float(row.get("stck_lwpr") or 0),
                "close": float(row.get("stck_clpr") or 0),
                "volume": int(row.get("acml_vol") or 0),
            }
        )
    return out


def ping() -> dict[str, Any]:
    """토큰 발급만 시도해서 키 유효성 확인."""
    if not _has_keys():
        return {"status": "skipped_missing_key"}
    try:
        tok = get_token()
        return {"status": "ok", "token_prefix": tok[:8] + "...", "len": len(tok)}
    except SkippedMissingKey:
        return {"status": "skipped_missing_key"}
    except Exception as exc:  # noqa: BLE001
        return {"status": "failed", "error": str(exc)}