import { FinanceCalculator } from '../src/core/finance/finance.calculator';

describe('FinanceCalculator (TDD 测试套件: 财务与分销计算引擎)', () => {
  let calculator: FinanceCalculator;

  beforeEach(() => {
    calculator = new FinanceCalculator();
  });

  describe('1. 平台抽成与大神分润计算', () => {
    it('100元订单按10%抽成，平台得10元，大神得90元', () => {
      const result = calculator.splitOrderIncome({
        orderAmountCents: 10000, // 100.00 元
        platformRatePercent: 10,
      });

      expect(result.platformFeeCents).toBe(1000); // 10.00 元
      expect(result.expertIncomeCents).toBe(9000); // 90.00 元
      expect(result.platformFeeCents + result.expertIncomeCents).toBe(10000);
    });

    it('出现小数分位时，向下取整平台抽成，保证资金平衡无漂移', () => {
      const result = calculator.splitOrderIncome({
        orderAmountCents: 3333, // 33.33 元
        platformRatePercent: 15, // 15% -> 499.95 分
      });

      expect(result.platformFeeCents).toBe(499);
      expect(result.expertIncomeCents).toBe(2834);
      expect(result.platformFeeCents + result.expertIncomeCents).toBe(3333);
    });
  });

  describe('2. 二级分销佣金分润计算', () => {
    it('100元订单，一级分销商得5元，二级分销商得2元', () => {
      const comm = calculator.calculateDistribution({
        orderAmountCents: 10000,
        level1Percent: 5,
        level2Percent: 2,
        hasLevel1: true,
        hasLevel2: true,
      });

      expect(comm.level1Cents).toBe(500); // 5.00 元
      expect(comm.level2Cents).toBe(200); // 2.00 元
      expect(comm.totalCommissionCents).toBe(700);
    });

    it('只有一级推荐人时，仅发放一级佣金', () => {
      const comm = calculator.calculateDistribution({
        orderAmountCents: 20000,
        level1Percent: 5,
        level2Percent: 2,
        hasLevel1: true,
        hasLevel2: false,
      });

      expect(comm.level1Cents).toBe(1000);
      expect(comm.level2Cents).toBe(0);
      expect(comm.totalCommissionCents).toBe(1000);
    });
  });

  describe('3. 优惠券抵扣计算', () => {
    it('订单满100减20，实付80元', () => {
      const payAmount = calculator.applyCoupon({
        orderAmountCents: 10000,
        couponDiscountCents: 2000,
        minOrderThresholdCents: 8000,
      });

      expect(payAmount).toBe(8000);
    });

    it('未达到优惠券门槛时应抛出异常', () => {
      expect(() => {
        calculator.applyCoupon({
          orderAmountCents: 5000, // 50元
          couponDiscountCents: 2000,
          minOrderThresholdCents: 8000, // 需满80元
        });
      }).toThrow('订单未达到优惠券使用门槛');
    });

    it('优惠券减免额大于订单总额时，实付金额应为0而不是负数', () => {
      const payAmount = calculator.applyCoupon({
        orderAmountCents: 3000,
        couponDiscountCents: 5000,
        minOrderThresholdCents: 0,
      });

      expect(payAmount).toBe(0);
    });
  });

  describe('4. 提现门槛与手续费校验', () => {
    it('低于最低提现额度(如50元)应抛出异常', () => {
      expect(() => {
        calculator.calculateWithdrawal({
          withdrawAmountCents: 3000, // 30元
          minLimitCents: 5000,      // 最低50元
          feePercent: 1,
        });
      }).toThrow('提现金额低于平台最低提现限额');
    });

    it('提现100元，手续费1%，实际打款99元', () => {
      const res = calculator.calculateWithdrawal({
        withdrawAmountCents: 10000,
        minLimitCents: 5000,
        feePercent: 1,
      });

      expect(res.feeCents).toBe(100);
      expect(res.actualArrivalCents).toBe(9900);
    });
  });
});