"""大盘行情总览（主页展示）。

- A 股指数走 pro.index_daily，全球指数走 pro.index_global（均为收盘口径，晚间更新；
  本 token 无 rt_idx_k 实时权限，故展示「最近交易日收盘」并标注日期）。
- 两市统计走 pro.daily_info：沪市取 SH_A、深市取 SZ_MARKET 汇总出
  总市值 / 流通市值 / 成交额（单位亿元，接口原生口径）。
- 整包结果写 Redis 缓存（TTL 可配）；单个指数拉取失败只是跳过（errors 里注明），
  全部失败才抛 MarketOverviewError —— 主页行情是锦上添花，不拖垮整页。
"""
from __future__ import annotations

import asyncio
import math
from datetime import date, datetime, timedelta

import pandas as pd

from .. import cache
from ..config import settings

# (代码, 名称, 地区) —— 展示顺序即列表顺序
MARKET_INDEXES: list[tuple[str, str, str]] = [
    ("000001.SH", "上证指数", "cn"),
    ("399001.SZ", "深证成指", "cn"),
    ("399006.SZ", "创业板指", "cn"),
    ("000688.SH", "科创50", "cn"),
    ("HSI", "恒生指数", "hk"),
    ("HKTECH", "恒生科技", "hk"),
    ("DJI", "道琼斯", "us"),
    ("IXIC", "纳斯达克", "us"),
    ("SPX", "标普500", "us"),
]

_SPARK_DAYS = 45        # 迷你走势取最近 45 个交易日收盘
_HISTORY_DAYS = 150     # 日历日窗口（约 100 个交易日，够取 spark）
_CALL_INTERVAL = 0.12   # 顺序调用间隔（秒），对 tushare 控频
_CACHE_KEY = "market_overview:v1"


class MarketOverviewError(RuntimeError):
    """所有指数都拉不到（token/网络故障）——接口层转 503。"""


def _f(v) -> float | None:
    """pandas 值 -> float；NaN/None -> None（否则 JSON 里会出现 NaN）。"""
    if v is None:
        return None
    try:
        f = float(v)
    except (TypeError, ValueError):
        return None
    return None if math.isnan(f) else f


def _d(v) -> date | None:
    return datetime.strptime(str(v), "%Y%m%d").date() if v else None


def _get_pro():
    if not settings.tushare_token:
        raise MarketOverviewError("未配置 TUSHARE_TOKEN，无法获取大盘行情（backend/.env）")
    import tushare as ts

    ts.set_token(settings.tushare_token)
    return ts.pro_api()


def _fetch_index_sync(pro, ts_code: str) -> pd.DataFrame:
    start = (datetime.now() - timedelta(days=_HISTORY_DAYS)).strftime("%Y%m%d")
    if "." in ts_code:  # A 股指数（000001.SH 形式）
        return pro.index_daily(ts_code=ts_code, start_date=start)
    return pro.index_global(ts_code=ts_code, start_date=start)


def _quote_from_df(df: pd.DataFrame) -> dict | None:
    """DataFrame -> {close, change, pct_chg, trade_date, spark, spark_dates}（旧 -> 新）。"""
    if df is None or df.empty:
        return None
    df = df.sort_values("trade_date")
    tail = df.tail(_SPARK_DAYS)
    last = df.iloc[-1]
    return {
        "close": _f(last["close"]),
        "change": _f(last.get("change")),
        "pct_chg": _f(last.get("pct_chg")),
        "trade_date": _d(last["trade_date"]),
        "spark": [round(float(c), 4) for c in tail["close"]],
        "spark_dates": [str(d) for d in tail["trade_date"]],
    }


def _fetch_stats_sync(pro) -> dict | None:
    """两市市值/成交统计：沪 SH_A + 深 SZ_MARKET（同一天口径相加，亿元）。"""
    start = (datetime.now() - timedelta(days=14)).strftime("%Y%m%d")
    sh = pro.daily_info(exchange="SH", start_date=start)
    sz = pro.daily_info(exchange="SZ", start_date=start)
    if sh is None or sh.empty or sz is None or sz.empty:
        return None

    def _board(df: pd.DataFrame, code: str):
        sub = df[df["ts_code"] == code].sort_values("trade_date")  # 接口不保证有序
        return sub.iloc[-1] if not sub.empty else None

    sh_a, sz_m = _board(sh, "SH_A"), _board(sz, "SZ_MARKET")
    if sh_a is None or sz_m is None:
        return None
    # 两边各自取最新，日期不一致时以较旧一天为准凑齐口径（罕见，通常同日）
    d = min(_d(sh_a["trade_date"]), _d(sz_m["trade_date"]))

    def _sum(col: str) -> float | None:
        a, b = _f(sh_a.get(col)), _f(sz_m.get(col))
        return None if a is None or b is None else round(a + b, 2)

    return {
        "trade_date": d,
        "total_mv": _sum("total_mv"),
        "float_mv": _sum("float_mv"),
        "amount": _sum("amount"),
        "turnover": _f(sh_a.get("tr")),  # 换手率仅沪市有，展示口径注明沪市
    }


async def fetch_overview() -> dict:
    """聚合全部指数 + 两市统计（Redis 缓存整包，TTL 内直接回）。"""
    cached = await cache.cache_get(_CACHE_KEY)
    if cached is not None:
        return cached

    pro = await asyncio.to_thread(_get_pro)

    indexes: list[dict] = []
    errors: list[str] = []
    for ts_code, name, region in MARKET_INDEXES:
        try:
            df = await asyncio.to_thread(_fetch_index_sync, pro, ts_code)
            q = _quote_from_df(df)
            if q is None:
                raise MarketOverviewError("无数据")
            indexes.append({"code": ts_code, "name": name, "region": region, **q})
        except Exception as e:  # noqa: BLE001 —— 单个指数失败不拖垮整包
            errors.append(f"{name}: {str(e)[:60]}")
        await asyncio.sleep(_CALL_INTERVAL)

    if not indexes:
        raise MarketOverviewError("大盘行情全部拉取失败: " + "; ".join(errors)[:200])

    stats: dict | None = None
    try:
        await asyncio.sleep(_CALL_INTERVAL)
        stats = await asyncio.to_thread(_fetch_stats_sync, pro)
    except Exception as e:  # noqa: BLE001 —— 统计缺失时指数照常展示
        errors.append(f"两市统计: {str(e)[:60]}")

    payload = {
        "updated_at": datetime.now(),
        "indexes": indexes,
        "stats": stats,
        "errors": errors,
    }
    await cache.cache_set(_CACHE_KEY, payload, ttl=settings.market_overview_ttl)
    return payload