Mutual_Fund/schemas/purchase.py

"""申购相关 DTO。"""
from decimal import Decimal

from pydantic import BaseModel, Field, field_serializer

from schemas.holdings import HoldingResp


class PurchaseReq(BaseModel):
    """申购入参。amount 为正数（元），按净值折算份额。"""

    product_id: int
    amount: Decimal = Field(gt=0)


class PurchaseResp(BaseModel):
    """申购结果：order_no + status（已确认 / 风控挂起）。

    已确认时返回最新余额 + 该产品持仓；风控挂起时账户/持仓不变，仅返回预警关联。
    """

    order_no: str
    status: str
    balance: Decimal | None = None
    holding: HoldingResp | None = None
    alert_id: int | None = None

    @field_serializer("balance")
    def _fmt_balance(self, value: Decimal | None) -> str | None:
        return f"{value:.2f}" if value is not None else None