import {
  CurrencyTaxCalculatorService,
  convertCurrency,
  calculateInternationalTax,
} from '../../../src/modules/team/service/currency-tax';
import { TaxCalculationResult } from '../../../src/comm/types/omni';

describe('Point 57 (P1): 跨国多币种汇率换算与国际发票税制计算', () => {
  let service: CurrencyTaxCalculatorService;

  beforeEach(() => {
    service = new CurrencyTaxCalculatorService();
  });

  describe('1. convertCurrency (多币种汇率精准换算)', () => {
    it('美元 USD 换算为阿联酋迪拉姆 AED (固定汇率 ~3.6725)', () => {
      // 100 USD -> 367.25 AED
      const aed = convertCurrency(100, 'USD', 'AED');
      expect(aed).toBe(367.25);
    });

    it('欧元 EUR 换算为美元 USD', () => {
      // 100 EUR -> 108 USD (基于 1.08 基准汇率)
      const usd = convertCurrency(100, 'EUR', 'USD');
      expect(usd).toBe(108);
    });

    it('同币种换算应保持原数值', () => {
      expect(convertCurrency(500, 'USD', 'USD')).toBe(500);
      expect(convertCurrency(800, 'AED', 'AED')).toBe(800);
    });

    it('不支持的币种应抛出明确异常保护', () => {
      expect(() => convertCurrency(100, 'USD', 'XYZ' as any)).toThrow();
    });
  });

  describe('2. calculateInternationalTax (国际合规发票税制计算)', () => {
    it('阿联酋企业或个人消费应按 5% VAT 计税', () => {
      const res = calculateInternationalTax({
        amount: 1000,
        currency: 'AED',
        country: 'AE',
        isB2b: true,
      });

      expect(res.taxRate).toBe(0.05);
      expect(res.taxAmount).toBe(50);
      expect(res.totalAmount).toBe(1050);
      expect(res.taxName).toBe('UAE VAT');
    });

    it('欧盟企业间跨国 B2B (Reverse Charge) 应适用反向征税 0% VAT', () => {
      const res = calculateInternationalTax({
        amount: 2000,
        currency: 'EUR',
        country: 'DE', // 德国
        isB2b: true,
        vatNumber: 'DE123456789',
      });

      expect(res.taxRate).toBe(0);
      expect(res.taxAmount).toBe(0);
      expect(res.totalAmount).toBe(2000);
      expect(res.isReverseCharge).toBe(true);
      expect(res.taxName).toContain('Reverse Charge');
    });

    it('零税区或未开税国家 (如免税州/部分离岸) 税额为 0', () => {
      const res = calculateInternationalTax({
        amount: 500,
        currency: 'USD',
        country: 'US',
        isB2b: true,
      });

      expect(res.taxRate).toBe(0);
      expect(res.taxAmount).toBe(0);
      expect(res.totalAmount).toBe(500);
    });
  });

  describe('3. CurrencyTaxCalculatorService 综合结算账单生成', () => {
    it('应生成包含格式化币种符号与详细税务明细的结算单', async () => {
      const invoice = await service.generateTaxInvoiceSummary({
        baseAmountUsd: 199, // 199 美元标准版年费
        targetCurrency: 'AED',
        billingCountry: 'AE',
        isB2b: true,
      });

      expect(invoice.currency).toBe('AED');
      expect(invoice.currencySymbol).toBe('AED ');
      expect(invoice.subtotal).toBeCloseTo(730.83, 1);
      expect(invoice.taxAmount).toBeGreaterThan(0);
      expect(invoice.totalAmount).toBeGreaterThan(invoice.subtotal);
    });
  });
});