"""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


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 option_position_limit_block_msg(
    ex: Any,
    *,
    opening_inst_id: str = "",
    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
    - 加仓已有合约(opening_inst_id 已在持仓中):不占新笔数,放行
    - 拉持仓失败:拒绝开仓(避免绕过上限)
    """
    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)
    if _inst_already_open(rows, opening_inst_id):
        return None
    if active >= mx:
        return f"期权持仓已达上限({active}/{mx}),请先平仓后再开"
    return None