import { describe, it, expect } from 'vitest';
import type { BillingViewData } from '@/lib/view-data/BillingViewData';
import { BillingViewModel, PaymentMethodViewModel, InvoiceViewModel, BillingStatsViewModel } from './BillingViewModel';

describe('BillingViewModel', () => {
  it('maps arrays of payment methods, invoices and stats into view models', () => {
    const viewData: BillingViewData = {
      paymentMethods: [
        {
          id: 'pm-1',
          type: 'card',
          last4: '4242',
          brand: 'Visa',
          isDefault: true,
          expiryMonth: 12,
          expiryYear: 2030,
          displayLabel: 'Visa •••• 4242',
          expiryDisplay: '12/2030',
        },
      ],
      invoices: [
        {
          id: 'inv-1',
          invoiceNumber: 'INV-1',
          date: '2024-01-01',
          dueDate: '2024-02-01',
          amount: 100,
          vatAmount: 19,
          totalAmount: 119,
          status: 'pending',
          description: 'Sponsorship',
          sponsorshipType: 'league',
          pdfUrl: 'https://example.com/invoice.pdf',
          formattedTotalAmount: '€119,00',
          formattedVatAmount: '€19,00',
          formattedDate: '2024-01-01',
          isOverdue: false,
        },
      ],
      stats: {
        totalSpent: 1000,
        pendingAmount: 200,
        nextPaymentDate: '2024-03-01',
        nextPaymentAmount: 50,
        activeSponsorships: 3,
        averageMonthlySpend: 250,
        formattedTotalSpent: '€1.000,00',
        formattedPendingAmount: '€200,00',
        formattedNextPaymentAmount: '€50,00',
        formattedAverageMonthlySpend: '€250,00',
        formattedNextPaymentDate: '2024-03-01',
      },
    };

    const vm = new BillingViewModel(viewData);

    expect(vm.paymentMethods).toHaveLength(1);
    expect(vm.paymentMethods[0]).toBeInstanceOf(PaymentMethodViewModel);
    expect(vm.invoices).toHaveLength(1);
    expect(vm.invoices[0]).toBeInstanceOf(InvoiceViewModel);
    expect(vm.stats).toBeInstanceOf(BillingStatsViewModel);
  });
});

describe('PaymentMethodViewModel', () => {
  it('builds displayLabel based on type and bankName/brand', () => {
    const card = {
      id: 'pm-1',
      type: 'card' as const,
      last4: '4242',
      brand: 'Visa',
      isDefault: true,
      displayLabel: 'Visa •••• 4242',
      expiryDisplay: null,
    };

    const sepa = {
      id: 'pm-2',
      type: 'sepa' as const,
      last4: '1337',
      bankName: 'Test Bank',
      isDefault: false,
      displayLabel: 'Test Bank •••• 1337',
      expiryDisplay: null,
    };

    const cardVm = new PaymentMethodViewModel(card);
    const sepaVm = new PaymentMethodViewModel(sepa);

    expect(cardVm.displayLabel).toBe('Visa •••• 4242');
    expect(sepaVm.displayLabel).toBe('Test Bank •••• 1337');
  });

  it('returns expiryDisplay when month and year are provided', () => {
    const withExpiry = {
      id: 'pm-1',
      type: 'card' as const,
      last4: '4242',
      brand: 'Visa',
      isDefault: true,
      expiryMonth: 3,
      expiryYear: 2030,
      displayLabel: 'Visa •••• 4242',
      expiryDisplay: '03/2030',
    };

    const withoutExpiry = {
      id: 'pm-2',
      type: 'card' as const,
      last4: '9999',
      brand: 'Mastercard',
      isDefault: false,
      displayLabel: 'Mastercard •••• 9999',
      expiryDisplay: null,
    };

    const withExpiryVm = new PaymentMethodViewModel(withExpiry);
    const withoutExpiryVm = new PaymentMethodViewModel(withoutExpiry);

    expect(withExpiryVm.expiryDisplay).toBe('03/2030');
    expect(withoutExpiryVm.expiryDisplay).toBeNull();
  });
});

describe('InvoiceViewModel', () => {
  it('formats monetary amounts and dates', () => {
    const viewData = {
      id: 'inv-1',
      invoiceNumber: 'INV-1',
      date: '2024-01-15',
      dueDate: '2024-02-01',
      amount: 100,
      vatAmount: 19,
      totalAmount: 119,
      status: 'paid' as const,
      description: 'Sponsorship',
      sponsorshipType: 'league' as const,
      pdfUrl: 'https://example.com/invoice.pdf',
      formattedTotalAmount: '€119,00',
      formattedVatAmount: '€19,00',
      formattedDate: '2024-01-15',
      isOverdue: false,
    };

    const vm = new InvoiceViewModel(viewData);

    expect(vm.formattedTotalAmount).toBe('€119,00');
    expect(vm.formattedVatAmount).toBe('€19,00');
    expect(typeof vm.formattedDate).toBe('string');
  });

  it('detects overdue when status is overdue or pending past due date', () => {
    const now = new Date();
    const pastDate = new Date(now.getTime() - 24 * 60 * 60 * 1000).toISOString();
    const futureDate = new Date(now.getTime() + 24 * 60 * 60 * 1000).toISOString();

    const overdue = {
      id: 'inv-1',
      invoiceNumber: 'INV-1',
      date: pastDate,
      dueDate: pastDate,
      amount: 0,
      vatAmount: 0,
      totalAmount: 0,
      status: 'overdue' as const,
      description: '',
      sponsorshipType: 'league' as const,
      pdfUrl: '',
      formattedTotalAmount: '€0,00',
      formattedVatAmount: '€0,00',
      formattedDate: pastDate,
      isOverdue: true,
    };

    const pendingPastDue = {
      id: 'inv-2',
      invoiceNumber: 'INV-2',
      date: pastDate,
      dueDate: pastDate,
      amount: 0,
      vatAmount: 0,
      totalAmount: 0,
      status: 'pending' as const,
      description: '',
      sponsorshipType: 'league' as const,
      pdfUrl: '',
      formattedTotalAmount: '€0,00',
      formattedVatAmount: '€0,00',
      formattedDate: pastDate,
      isOverdue: true,
    };

    const pendingFuture = {
      id: 'inv-3',
      invoiceNumber: 'INV-3',
      date: pastDate,
      dueDate: futureDate,
      amount: 0,
      vatAmount: 0,
      totalAmount: 0,
      status: 'pending' as const,
      description: '',
      sponsorshipType: 'league' as const,
      pdfUrl: '',
      formattedTotalAmount: '€0,00',
      formattedVatAmount: '€0,00',
      formattedDate: pastDate,
      isOverdue: false,
    };

    const overdueVm = new InvoiceViewModel(overdue);
    const pendingPastDueVm = new InvoiceViewModel(pendingPastDue);
    const pendingFutureVm = new InvoiceViewModel(pendingFuture);

    expect(overdueVm.isOverdue).toBe(true);
    expect(pendingPastDueVm.isOverdue).toBe(true);
    expect(pendingFutureVm.isOverdue).toBe(false);
  });
});

describe('BillingStatsViewModel', () => {
  it('formats monetary fields and next payment date', () => {
    const viewData = {
      totalSpent: 1234,
      pendingAmount: 56.78,
      nextPaymentDate: '2024-03-01',
      nextPaymentAmount: 42,
      activeSponsorships: 2,
      averageMonthlySpend: 321,
      formattedTotalSpent: '€1.234,00',
      formattedPendingAmount: '€56,78',
      formattedNextPaymentAmount: '€42,00',
      formattedAverageMonthlySpend: '€321,00',
      formattedNextPaymentDate: '2024-03-01',
    };

    const vm = new BillingStatsViewModel(viewData);

    expect(vm.formattedTotalSpent).toBe('€1.234,00');
    expect(vm.formattedPendingAmount).toBe('€56,78');
    expect(vm.formattedNextPaymentAmount).toBe('€42,00');
    expect(vm.formattedAverageMonthlySpend).toBe('€321,00');
    expect(typeof vm.formattedNextPaymentDate).toBe('string');
  });
});