juwan-frontend/lib/domain/income.ts

import type { Shop } from "@/lib/types"

type ShopCommission = Pick<Shop, "commissionType" | "commissionValue">

export interface IncomeCalculation {
  income: number
  commissionLabel: string
}

function roundCurrency(amount: number) {
  return Number(amount.toFixed(2))
}

export function calculateOrderIncome(totalPrice: number, shop?: ShopCommission): IncomeCalculation {
  if (!shop) {
    return {
      income: roundCurrency(totalPrice),
      commissionLabel: "独立接单无抽成",
    }
  }

  if (shop.commissionType === "percentage") {
    return {
      income: roundCurrency(totalPrice * (1 - shop.commissionValue / 100)),
      commissionLabel: `扣除${shop.commissionValue}%抽成`,
    }
  }

  return {
    income: roundCurrency(Math.max(0, totalPrice - shop.commissionValue)),
    commissionLabel: `扣除¥${shop.commissionValue}固定抽成`,
  }
}