"""A 股指数全量日线（上证指数日 K 图数据源）。

candles 表只有 6 位纯代码股票（TDX 导入明确排除指数，sh000001 与 sz000001 平安银行
无法区分），指数走 tushare index_daily 按需拉取：分页拉全量（1990 年至今 ~8900 根），
进程内 + Redis 两级缓存，历史不可变、TTL 兜到当日更新。
"""
from __future__ import annotations

import asyncio
import json
import time
from datetime import datetime

from .. import cache
from ..domain import Bar

_PAGE = 8000        # index_daily 单次返回上限
_TTL = 7200         # 缓存 2h：历史不可变，只影响当日 bar 的新鲜度
_CALL_GAP = 0.12    # 分页请求间隔（秒），对 tushare 控频（与 market_overview 同款）

SH_INDEX = "000001.SH"

# 进程内缓存：ts_code -> (bars, 过期时刻)。bars 为全量日线（升序）
_mem: dict[str, tuple[list[Bar], float]] = {}


def _fetch_all_sync(ts_code: str) -> list[Bar]:
    """分页拉全量日线。vol 单位手 -> 股，amount 千元 -> 元（与 fetch_daily 同款换算）。"""
    from .tushare_provider import get_pro

    pro = get_pro()
    frames = []
    offset = 0
    while True:
        df = pro.index_daily(ts_code=ts_code, offset=offset, limit=_PAGE)
        if df is None or df.empty:
            break
        frames.append(df)
        if len(df) < _PAGE:
            break
        offset += _PAGE
        time.sleep(_CALL_GAP)
    if not frames:
        raise RuntimeError(f"Tushare index_daily 无数据: {ts_code}")

    import pandas as pd

    df = pd.concat(frames).drop_duplicates(subset="trade_date").sort_values("trade_date")
    bars: list[Bar] = []
    for _, r in df.iterrows():
        amt = r.get("amount")
        bars.append(
            Bar(
                ts=datetime.strptime(str(r["trade_date"]), "%Y%m%d"),
                open=float(r["open"]), high=float(r["high"]),
                low=float(r["low"]), close=float(r["close"]),
                volume=float(r["vol"]) * 100.0,
                amount=float(amt) * 1000.0 if amt is not None and amt == amt else None,
            )
        )
    return bars


def _to_raw(bars: list[Bar]) -> str:
    """紧凑 JSON：[[ts_iso, open, high, low, close, volume, amount|null], ...]（~600KB）。"""
    return json.dumps(
        [[b.ts.isoformat(), b.open, b.high, b.low, b.close, b.volume, b.amount] for b in bars],
        ensure_ascii=False, separators=(",", ":"),
    )


def _from_raw(raw: str) -> list[Bar]:
    return [
        Bar(ts=datetime.fromisoformat(row[0]), open=row[1], high=row[2], low=row[3],
            close=row[4], volume=row[5], amount=row[6])
        for row in json.loads(raw)
    ]


async def get_index_daily(ts_code: str = SH_INDEX) -> list[Bar]:
    """全量日线（升序）：进程内 -> Redis -> tushare，未命中层级回填上一级。"""
    hit = _mem.get(ts_code)
    if hit and hit[1] > time.monotonic():
        return hit[0]

    key = f"idxd:{ts_code}"
    raw = await cache.cache_get(key)
    if isinstance(raw, str):
        bars = _from_raw(raw)
        _mem[ts_code] = (bars, time.monotonic() + _TTL)
        return bars

    bars = await asyncio.to_thread(_fetch_all_sync, ts_code)
    _mem[ts_code] = (bars, time.monotonic() + _TTL)
    await cache.cache_set(key, _to_raw(bars), ttl=_TTL)
    return bars