"""OKX 期权/对冲模式(env: OKX_TRADE_MODE).

options         → 仅单独期权(隐藏对冲导航与对冲 env 配置)
options_options → 仅期期对冲(不可单独开期权)
perp_options    → 永期对冲(含合约腿);产品 UI 已隐藏,仅兼容旧 .env / 历史计划
"""
from __future__ import annotations

import os
from typing import Optional

MODE_OPTIONS = "options"
MODE_PERP = "perp_options"
MODE_OO = "options_options"
VALID_MODES = frozenset({MODE_OPTIONS, MODE_PERP, MODE_OO})
# 配置页可选模式(不含永期)
UI_MODES = frozenset({MODE_OPTIONS, MODE_OO})

_ALIASES = {
    "option": MODE_OPTIONS,
    "standalone": MODE_OPTIONS,
    "期权": MODE_OPTIONS,
    "单独期权": MODE_OPTIONS,
    "po": MODE_PERP,
    "perp": MODE_PERP,
    "永期": MODE_PERP,
    "永期对冲": MODE_PERP,
    "oo": MODE_OO,
    "期期": MODE_OO,
    "期期对冲": MODE_OO,
}


def _env_bool(name: str, default: bool = False) -> bool:
    raw = os.getenv(name)
    if raw is None or str(raw).strip() == "":
        return default
    return str(raw).strip().lower() in ("1", "true", "yes", "on")


def normalize_okx_trade_mode(raw: Optional[str]) -> str:
    s = str(raw or "").strip().lower()
    if s in VALID_MODES:
        return s
    if s in _ALIASES:
        return _ALIASES[s]
    return ""


def legacy_infer_okx_trade_mode() -> str:
    """未配置 OKX_TRADE_MODE 时默认单独期权(对冲关闭).

    旧 HEDGE_PLAN_* 开关不再自动打开对冲,避免误开;需显式设 OKX_TRADE_MODE=options_options.
    """
    return MODE_OPTIONS


def get_okx_trade_mode() -> str:
    m = normalize_okx_trade_mode(os.getenv("OKX_TRADE_MODE"))
    if m:
        return m
    return legacy_infer_okx_trade_mode()


def hedge_module_enabled() -> bool:
    return get_okx_trade_mode() in (MODE_PERP, MODE_OO)


def show_perp_options() -> bool:
    return get_okx_trade_mode() == MODE_PERP


def show_options_options() -> bool:
    return get_okx_trade_mode() == MODE_OO


def standalone_options_open_allowed() -> bool:
    return get_okx_trade_mode() == MODE_OPTIONS


def mode_label(mode: Optional[str] = None) -> str:
    m = mode or get_okx_trade_mode()
    return {
        MODE_OPTIONS: "单独期权",
        MODE_PERP: "永期对冲",
        MODE_OO: "期期对冲",
    }.get(m, m or "—")


def block_standalone_open_by_mode_msg() -> Optional[str]:
    if standalone_options_open_allowed():
        return None
    return (
        f"当前交易模式为「{mode_label()}」,不可单独开期权;"
        "请在 env「交易模式」切换为「单独期权」"
    )