"""持仓相关 DTO。

金额字段序列化为字符串，避免 JSON number 浮点精度隐患；
份额 / 盈亏比例保留 4 位，金额保留 2 位。
"""
from decimal import Decimal

from pydantic import BaseModel, field_serializer


class HoldingResp(BaseModel):
    """单条持仓记录。"""

    id: int
    customer_id: int
    product_id: int
    shares: Decimal
    cost_amount: Decimal
    current_value: Decimal
    profit_loss: Decimal
    profit_ratio: Decimal
    status: str

    @field_serializer("shares", "profit_ratio")
    def _fmt_ratio(self, value: Decimal) -> str:
        return f"{value:.4f}"

    @field_serializer("cost_amount", "current_value", "profit_loss")
    def _fmt_money(self, value: Decimal) -> str:
        return f"{value:.2f}"