"""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：最新余额 + 该产品最新持仓。"""

    balance: Decimal
    holding: HoldingResp

    @field_serializer("balance")
    def _fmt_balance(self, value: Decimal) -> str:
        return f"{value:.2f}"