"""OKX 期权持仓笔数上限(env: OKX_OPTIONS_MAX_ACTIVE_POSITIONS)."""
from __future__ import annotations

import os
from typing import Any, Optional, Sequence


def options_max_active_positions() -> int:
    """同时持有的期权合约笔数上限;0=不限制.热更读 env."""
    raw = os.getenv("OKX_OPTIONS_MAX_ACTIVE_POSITIONS", "0")
    try:
        v = int(float(str(raw).strip()))
    except (TypeError, ValueError):
        return 0
    return max(0, v)


def count_live_option_positions(rows: Optional[list[dict[str, Any]]]) -> int:
    if not rows:
        return 0
    n = 0
    for r in rows:
        if not isinstance(r, dict):
            continue
        try:
            pos = float(r.get("pos") or 0)
        except (TypeError, ValueError):
            continue
        if abs(pos) >= 1e-12:
            n += 1
    return n


def _inst_already_open(rows: list[dict[str, Any]], inst_id: str) -> bool:
    want = (inst_id or "").strip()
    if not want:
        return False
    for r in rows:
        if str(r.get("instId") or r.get("inst_id") or "").strip() == want:
            return True
    return False


def _normalize_inst_ids(
    opening_inst_id: str = "",
    opening_inst_ids: Optional[Sequence[str]] = None,
) -> list[str]:
    out: list[str] = []
    seen: set[str] = set()
    for raw in list(opening_inst_ids or []) + ([opening_inst_id] if opening_inst_id else []):
        iid = str(raw or "").strip()
        if not iid or iid in seen:
            continue
        seen.add(iid)
        out.append(iid)
    return out


def option_position_limit_block_msg(
    ex: Any,
    *,
    opening_inst_id: str = "",
    opening_inst_ids: Optional[Sequence[str]] = None,
    new_positions: Optional[int] = None,
    max_active: Optional[int] = None,
    fetch_positions=None,
) -> Optional[str]:
    """若禁止新开买期权则返回中文原因,否则 None.

    - max_active<=0:不限制
    - opening_inst_ids:本次要开的合约;已在持仓中的不占新笔数
    - new_positions:显式指定还需新占几笔(默认按 opening_inst_ids 推算)
    - 期期两腿应一次传入两个 inst_id,在开仓前预检,避免上限=1 时开出半边仓
    - 拉持仓失败:拒绝开仓(避免绕过上限)
    """
    try:
        from lib.hedge_plan.okx_trade_mode_lib import standalone_options_open_allowed

        # 对冲模式用 MAX_ACTIVE_HEDGE_PLANS 管「组数」,不占用期权笔数上限
        if max_active is None and not standalone_options_open_allowed():
            return None
    except Exception:
        pass
    mx = options_max_active_positions() if max_active is None else int(max_active)
    if mx <= 0:
        return None
    fetch = fetch_positions
    if fetch is None:
        from lib.exchange.okx_options_lib import fetch_option_positions

        fetch = fetch_option_positions
    try:
        rows = fetch(ex)
    except Exception:
        rows = None
    if rows is None:
        return f"无法获取期权持仓,暂不可开仓(上限 {mx} 笔)"
    active = count_live_option_positions(rows)
    ids = _normalize_inst_ids(opening_inst_id, opening_inst_ids)

    if new_positions is None:
        if ids:
            already = sum(1 for i in ids if _inst_already_open(rows, i))
            need = max(0, len(ids) - already)
        else:
            need = 1
    else:
        need = max(0, int(new_positions))
        if need <= 1 and len(ids) == 1 and _inst_already_open(rows, ids[0]):
            return None

    if need <= 0:
        return None
    if active + need <= mx:
        return None
    if need >= 2:
        return (
            f"期期对冲需新开 {need} 笔期权,当前已有 {active} 笔、上限 {mx};"
            f"请将 OKX_OPTIONS_MAX_ACTIVE_POSITIONS 设为 0(不限制)或不小于 {active + need},或先平仓"
        )
    return f"期权持仓已达上限({active}/{mx}),请先平仓后再开"