from __future__ import annotations

from typing import Annotated

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel, Field

from ..market import get_gateway
from ..models.db import get_db
from ..sim.matcher import Matcher
from ..strategy.clock import window_key
from ..strategy.group import next_group_id
from ..strategy.signal import decide
from .auth import require_user

router = APIRouter(prefix="/api/sim", tags=["sim"])


class ManualOpenBody(BaseModel):
    """可选强制方向；默认按卖一比价自动选。"""
    force_option_side: str | None = Field(default=None, description="call|put")


@router.get("/ledger")
async def sim_ledger(_user: Annotated[str, Depends(require_user)]) -> dict:
    return Ledger().snapshot()


@router.get("/position")
async def sim_position(_user: Annotated[str, Depends(require_user)]) -> dict:
    m = Matcher()
    return {"position": m.current_position(), "unrealized": m.unrealized()}


@router.post("/open-group")
async def sim_open_group(
    _user: Annotated[str, Depends(require_user)],
    body: ManualOpenBody | None = None,
) -> dict:
    gw = get_gateway()
    # 开仓前按现价强制重选 ATM，避免沿用启动时的旧行权价
    try:
        await gw.ensure_atm_async(force=True)
    except Exception as e:
        raise HTTPException(status_code=503, detail=f"ATM 对齐失败: {e}") from e
    snap = gw.snapshot()
    if not snap.pair or not snap.call or not snap.put:
        raise HTTPException(status_code=503, detail="行情未就绪")
    force = (body.force_option_side if body else None) or None
    if force in ("call", "put"):
        option_side = force
        perp_side = "short" if force == "call" else "long"
        bias = "manual_" + force
    else:
        sig = decide(snap.call.ask, snap.put.ask)
        if sig is None:
            raise HTTPException(status_code=409, detail="Call/Put 卖一相等，跳过")
        option_side = sig.option_side
        perp_side = sig.perp_side
        bias = sig.bias

    option_inst = (
        snap.pair.call_inst_id if option_side == "call" else snap.pair.put_inst_id
    )
    entry_idx = snap.index_px or (snap.perp.mark_px if snap.perp else None)
    if entry_idx is None:
        raise HTTPException(status_code=503, detail="无指数/标记价")

    wkey = window_key()
    db = get_db()
    count = len(db.fetchall("SELECT group_id FROM groups WHERE group_id LIKE ?", (f"G-{wkey}-%",)))
    gid = next_group_id(count)
    r = Matcher().open_group(
        group_id=gid,
        bias=bias,
        option_side=option_side,
        perp_side=perp_side,
        option_inst_id=option_inst,
        entry_index_px=float(entry_idx),
        strike=snap.pair.strike,
        expiry_ymd=snap.pair.expiry_ymd,
    )
    if not r.ok:
        raise HTTPException(status_code=400, detail=r.detail)
    return {"ok": True, **(r.data or {}), "detail": r.detail}


@router.post("/close-group")
async def sim_close_group(_user: Annotated[str, Depends(require_user)]) -> dict:
    r = Matcher().close_group(reason="manual")
    if not r.ok and not r.liquidity_wait:
        raise HTTPException(status_code=400, detail=r.detail)
    return {
        "ok": r.ok,
        "liquidity_wait": r.liquidity_wait,
        "detail": r.detail,
        "data": r.data,
    }