"""行情网关：REST 对齐合约 + WS 推送盘口。"""

from __future__ import annotations

import asyncio
import logging
from dataclasses import dataclass
from typing import Any

from ..config import Settings, get_settings
from .book_cache import BookCache
from .instruments import (
    hours_until_expiry,
    list_eligible_expiry_ymds,
    option_leverage,
    select_option_pair,
)
from .okx_rest import OkxRestClient
from .okx_ws import OkxPublicWs
from .types import MarketSnapshot, OptionPair

logger = logging.getLogger(__name__)

# 展示用：现价偏离当前行权超过该点数则重选 ATM（空仓）
_ATM_DRIFT_POINTS = 5.0


def _has_open_position() -> bool:
    try:
        from ..models.db import get_db

        row = get_db().fetchone("SELECT status FROM positions WHERE id=1")
        return bool(row and row["status"] == "open")
    except Exception:
        return False


def _strategy_floats() -> tuple[float, float]:
    """(min_option_hours, min_option_leverage)"""
    s = get_settings()
    try:
        from ..models.db import get_db

        db = get_db()
        hours = float(
            db.get_setting("min_option_hours", str(s.min_option_hours))
            or s.min_option_hours
        )
        lev = float(
            db.get_setting("min_option_leverage", str(s.min_option_leverage))
            or s.min_option_leverage
        )
        return hours, lev
    except Exception:
        return s.min_option_hours, s.min_option_leverage


@dataclass(slots=True)
class OpenPick:
    pair: OptionPair
    option_side: str
    perp_side: str
    bias: str
    call_ask: float
    put_ask: float
    option_ask: float
    option_leverage: float
    hours_left: float
    underlying_px: float


class MarketGateway:
    def __init__(self, settings: Settings | None = None) -> None:
        self.settings = settings or get_settings()
        self.cache = BookCache()
        proxy = self.settings.okx_http_proxy or None
        self.rest = OkxRestClient(self.settings.okx_rest_base, proxy=proxy)
        self.ws = OkxPublicWs(self.settings.okx_ws_public, self.cache, proxy=proxy)
        self._pair: OptionPair | None = None
        self._refresh_task: asyncio.Task[None] | None = None
        self._started = False

    @property
    def pair(self) -> OptionPair | None:
        return self._pair

    async def start(self) -> None:
        if self._started:
            return
        self._started = True
        await asyncio.to_thread(self.align_instruments)
        await self.ws.start()
        self._refresh_task = asyncio.create_task(self._refresh_loop(), name="market-align")

    async def stop(self) -> None:
        self._started = False
        if self._refresh_task:
            self._refresh_task.cancel()
            try:
                await self._refresh_task
            except asyncio.CancelledError:
                pass
            self._refresh_task = None
        await self.ws.stop()
        self.rest.close()

    def _apply_pair(self, pair: OptionPair, *, mark: float, idx: float | None) -> OptionPair:
        s = self.settings
        self._pair = pair
        self.cache.set_pair(pair)
        if idx is not None:
            self.cache.set_index_px(idx)

        for inst in (s.perp_inst_id, pair.call_inst_id, pair.put_inst_id):
            bids, asks, ts = self.rest.fetch_books(inst, sz=5)
            self.cache.upsert_book(inst, bids=bids, asks=asks, ts_ms=ts)
            mp = self.rest.fetch_mark_price(inst)
            if mp:
                self.cache.set_mark_px(inst, mp)

        keep = {s.perp_inst_id, pair.call_inst_id, pair.put_inst_id}
        self.cache.drop_except(keep)
        self.ws.set_instruments([s.perp_inst_id, pair.call_inst_id, pair.put_inst_id])
        logger.info(
            "aligned pair expiry=%s strike=%s call=%s put=%s mark=%.2f hours=%.1f",
            pair.expiry_ymd,
            pair.strike,
            pair.call_inst_id,
            pair.put_inst_id,
            mark,
            hours_until_expiry(pair.expiry_ymd),
        )
        return pair

    def align_instruments(self) -> OptionPair | None:
        """空仓展示：选剩余时长合格的最近到期 ATM（不校验期权杠杆）。"""
        s = self.settings
        idx = self.rest.fetch_index_ticker(s.index_inst_id)
        mark = self.rest.fetch_mark_price(s.perp_inst_id) or idx
        if mark is None or mark <= 0:
            raise RuntimeError("无法获取 ETH 标记/指数价格，无法选 ATM")

        min_hours, _ = _strategy_floats()
        instruments = self.rest.fetch_option_instruments(s.option_inst_family)
        pair = select_option_pair(
            instruments, mark_px=float(mark), min_hours=min_hours
        )
        if pair is None:
            raise RuntimeError(
                f"未找到剩余≥{min_hours}h 的 ATM Call/Put (family={s.option_inst_family})"
            )
        return self._apply_pair(pair, mark=float(mark), idx=idx)

    def pick_for_open(self) -> OpenPick | None:
        """
        开仓选约：
        1) 剩余时长 ≥ min_hours 的到期日（由近到远）
        2) 该到期 ATM 平值
        3) 卖一比价定方向后校验 现价/卖一 ≥ min_option_leverage
        """
        s = self.settings
        min_hours, min_lev = _strategy_floats()
        idx = self.rest.fetch_index_ticker(s.index_inst_id)
        mark = self.rest.fetch_mark_price(s.perp_inst_id) or idx
        if mark is None or mark <= 0:
            return None
        underlying = float(mark)
        instruments = self.rest.fetch_option_instruments(s.option_inst_family)
        eligible = list_eligible_expiry_ymds(instruments, min_hours=min_hours)
        if not eligible:
            logger.info("no expiry with hours>=%.1f", min_hours)
            return None

        from ..strategy.signal import decide

        for ymd in eligible:
            pair = select_option_pair(
                instruments, mark_px=underlying, expiry_ymd=ymd
            )
            if pair is None:
                continue
            call_bids, call_asks, _ = self.rest.fetch_books(pair.call_inst_id, sz=5)
            put_bids, put_asks, _ = self.rest.fetch_books(pair.put_inst_id, sz=5)
            call_ask = call_asks[0].px if call_asks else None
            put_ask = put_asks[0].px if put_asks else None
            sig = decide(call_ask, put_ask)
            if sig is None:
                continue
            opt_ask = sig.call_ask if sig.option_side == "call" else sig.put_ask
            lev = option_leverage(underlying, opt_ask)
            hours_left = hours_until_expiry(ymd)
            if lev is None or lev + 1e-9 < min_lev:
                logger.info(
                    "skip expiry=%s strike=%.0f side=%s lev=%s need>=%.0f hours=%.1f",
                    ymd,
                    pair.strike,
                    sig.option_side,
                    f"{lev:.1f}" if lev else "n/a",
                    min_lev,
                    hours_left,
                )
                continue
            self._apply_pair(pair, mark=underlying, idx=idx)
            # 写入刚拉的盘口，避免 WS 尚未推送
            self.cache.upsert_book(pair.call_inst_id, bids=call_bids, asks=call_asks)
            self.cache.upsert_book(pair.put_inst_id, bids=put_bids, asks=put_asks)
            return OpenPick(
                pair=pair,
                option_side=sig.option_side,
                perp_side=sig.perp_side,
                bias=sig.bias,
                call_ask=float(sig.call_ask),
                put_ask=float(sig.put_ask),
                option_ask=float(opt_ask),
                option_leverage=float(lev),
                hours_left=hours_left,
                underlying_px=underlying,
            )
        return None

    async def realign_async(self) -> OptionPair | None:
        old = self._pair
        pair = await asyncio.to_thread(self.align_instruments)
        if old is None or (
            pair
            and (
                pair.call_inst_id != old.call_inst_id
                or pair.put_inst_id != old.put_inst_id
            )
        ):
            await self.ws.resubscribe(
                [
                    self.settings.perp_inst_id,
                    pair.call_inst_id,
                    pair.put_inst_id,
                ]
            )
        return pair

    async def pick_for_open_async(self) -> OpenPick | None:
        old = self._pair
        pick = await asyncio.to_thread(self.pick_for_open)
        if pick and (
            old is None
            or pick.pair.call_inst_id != old.call_inst_id
            or pick.pair.put_inst_id != old.put_inst_id
        ):
            await self.ws.resubscribe(
                [
                    self.settings.perp_inst_id,
                    pick.pair.call_inst_id,
                    pick.pair.put_inst_id,
                ]
            )
        return pick

    def _mark_for_atm(self) -> float | None:
        snap = self.snapshot()
        if snap.perp and snap.perp.mark_px:
            return float(snap.perp.mark_px)
        if snap.index_px:
            return float(snap.index_px)
        if snap.perp and snap.perp.bid and snap.perp.ask:
            return (float(snap.perp.bid) + float(snap.perp.ask)) / 2
        return None

    def atm_needs_realign(self, mark_px: float | None = None) -> bool:
        if self._pair is None:
            return True
        min_hours, _ = _strategy_floats()
        if hours_until_expiry(self._pair.expiry_ymd) + 1e-9 < min_hours:
            return True
        mark = mark_px if mark_px is not None else self._mark_for_atm()
        if mark is None or mark <= 0:
            return False
        return abs(float(self._pair.strike) - float(mark)) >= _ATM_DRIFT_POINTS

    async def ensure_atm_async(self, *, force: bool = False) -> OptionPair | None:
        """空仓时按剩余时长+ATM 对齐。有持仓不切换。"""
        if _has_open_position():
            return self._pair
        if force or self.atm_needs_realign():
            logger.info(
                "ATM realign force=%s old_strike=%s old_exp=%s",
                force,
                self._pair.strike if self._pair else None,
                self._pair.expiry_ymd if self._pair else None,
            )
            return await self.realign_async()
        return self._pair

    def snapshot(self) -> MarketSnapshot:
        return self.cache.snapshot(self.settings.perp_inst_id)

    def snapshot_dict(self) -> dict[str, Any]:
        return self.snapshot().to_dict()

    async def _refresh_loop(self) -> None:
        while True:
            await asyncio.sleep(30)
            try:
                idx = await asyncio.to_thread(
                    self.rest.fetch_index_ticker, self.settings.index_inst_id
                )
                self.cache.set_index_px(idx)
                mark = await asyncio.to_thread(
                    self.rest.fetch_mark_price, self.settings.perp_inst_id
                )
                if mark:
                    self.cache.set_mark_px(self.settings.perp_inst_id, mark)
                await self.ensure_atm_async(force=False)
            except asyncio.CancelledError:
                raise
            except Exception as e:
                logger.warning("market refresh failed: %s", e)


_gateway: MarketGateway | None = None


def get_gateway() -> MarketGateway:
    global _gateway
    if _gateway is None:
        _gateway = MarketGateway()
    return _gateway


def set_gateway(gw: MarketGateway | None) -> None:
    global _gateway
    _gateway = gw