"""趋势策略委托簿，对应 Go 客户端的 ``logic/order.go``。"""

from __future__ import annotations

import secrets
from dataclasses import dataclass
from datetime import datetime, timedelta
from threading import Lock
from typing import Any

# QMT 开平方向字段到本地买卖方向的映射。
OFFSET_FLAG = {"23": "BUY", "24": "SELL", "48": "BUY", "49": "SELL"}

# 表示委托仍在处理、可能继续成交的 QMT 状态。
BUSY_STATUSES = {"48", "49", "50", "51", "52", "55"}


@dataclass(frozen=True, slots=True)
class PlaceOrderRequest:
    """``OrderBook.place`` 提交委托所需的全部参数。"""

    client: Any
    op: int
    code: str
    volume: int
    order_id: str
    strategy_name: str


@dataclass(slots=True)
class OrderItem:
    """从 QMT 委托明细转换得到的本地订单记录。"""

    id: str
    code: str
    side: str
    remark: str
    status: str
    created_at: datetime | None
    volume: int
    local_order_id: str = ""


class OrderBook:
    """线程安全的活动委托缓存。"""

    def __init__(self, timeout_seconds: float = 300) -> None:
        self.timeout = timedelta(seconds=timeout_seconds)
        self.data: dict[str, OrderItem] = {}
        self.index: list[str] = []
        self.lock = Lock()

    @staticmethod
    def new_order_id(leg: str) -> str:
        """生成短订单号，为 QMT 备注中的信号键预留空间。"""
        return f"zt-{leg[:1]}-{secrets.token_hex(4)}"

    def is_lock(self, side: str, code: str) -> bool:
        """判断证券在指定买卖方向上是否已经被委托锁定。"""
        with self.lock:
            return f"{side}-{code}" in self.index

    def busy(self, code: str, side: str) -> bool:
        """判断证券是否存在仍在处理中的同方向委托。"""
        with self.lock:
            key = f"{side}-{code}"
            order = self.data.get(key)
            return key in self.index or bool(order and order.status in BUSY_STATUSES)

    def refresh(self, client: Any) -> None:
        """从 QMT 刷新当前委托明细和方向索引。"""
        parsed_orders = [
            parse_order(row) for row in client.trade_detail_data("order")
        ]
        with self.lock:
            self.data = {key: item for key, item in parsed_orders}
            self.index = [
                key for key, item in parsed_orders if item.status in BUSY_STATUSES
            ]

    def cancel_expired(self, client: Any, now: datetime | None = None) -> None:
        """尝试撤销超过有效期且具有委托编号的订单。"""
        self.refresh(client)
        current = now or datetime.now()

        # 使用快照遍历，避免网络调用期间长期持有互斥锁。
        for order in list(self.data.values()):
            if (
                order.created_at is not None
                and current - order.created_at > self.timeout
                and order.id
            ):
                client.cancel_by_id(order.id)

    def place(self, request: PlaceOrderRequest) -> bool:
        """按最新价提交委托，并立即写入本地方向锁。"""
        result = request.client.passorder_latest_tagged(
            request.op,
            request.code,
            request.volume,
            request.strategy_name,
            request.order_id,
        )
        if not isinstance(result, dict):
            return False
        order_ref = str(result.get("order_ref") or "").strip().lower()
        if result.get("status") != "success" or order_ref in {"", "unknown", "none"}:
            return False

        side = OFFSET_FLAG.get(str(request.op), "")
        pending = OrderItem(
            id=order_ref,
            code=request.code,
            side=side,
            remark=request.order_id,
            status="48",
            created_at=datetime.now(),
            volume=request.volume,
            local_order_id=request.order_id,
        )
        with self.lock:
            key = f"{side}-{request.code}"
            self.data[key] = pending
            if key not in self.index:
                self.index.append(key)
        return True


def parse_order(row: dict[str, Any]) -> tuple[str, OrderItem]:
    """把 QMT 原始委托字段转换为本地订单及其索引键。"""
    volume = _as_int(row.get("m_nVolumeTotal")) + _as_int(
        row.get("m_nVolumeTraded")
    )

    timestamp = _as_int(row.get("m_nOrderTime"))
    if timestamp > 100_000_000_000:
        # QMT 某些版本返回毫秒时间戳。
        timestamp /= 1000
    created_at = (
        datetime.fromtimestamp(timestamp)
        if timestamp
        else _parse_insert_datetime(row)
    )

    item = OrderItem(
        id=str(row.get("m_strOrderSysID") or ""),
        code=str(row.get("m_strInstrumentID") or ""),
        side=OFFSET_FLAG.get(str(row.get("m_nOffsetFlag")), ""),
        remark=str(row.get("m_strRemark") or ""),
        status=str(row.get("m_nOrderStatus") or ""),
        created_at=created_at,
        volume=volume,
        local_order_id=_local_order_id(str(row.get("m_strRemark") or "")),
    )
    return f"{item.side}-{item.code}", item


def _as_int(value: Any) -> int:
    """安全转换整数，无效值按 0 处理。"""
    try:
        return int(value or 0)
    except (TypeError, ValueError):
        return 0


def _parse_insert_datetime(row: dict[str, Any]) -> datetime | None:
    """使用委托日期和时间字段构造本地时间。"""
    date = str(row.get("m_strInsertDate") or "")
    clock = str(row.get("m_strInsertTime") or "").replace(":", "").zfill(6)
    try:
        return datetime.strptime(date + clock, "%Y%m%d%H%M%S")
    except ValueError:
        return None


def _local_order_id(remark: str) -> str:
    """兼容 ``local_order_id|signal_key`` 形式的 QMT 备注。"""
    return remark.split("|", 1)[0] if remark else ""