import { describe, it, expect, vi, beforeEach } from 'vitest'
import {
  createMockRequest,
  parseJsonResponse,
  createMockRouteParams,
  createQueuedMockSupabase,
  makeInvoice,
  makeCustomer,
  makeCompanySettings,
} from '@/tests/helpers'
import { eventBus } from '@/lib/events'

const { supabase: mockSupabase, enqueue, reset } = createQueuedMockSupabase()
vi.mock('@/lib/supabase/server', () => ({
  createClient: () => Promise.resolve(mockSupabase),
}))

vi.mock('@/lib/init', () => ({
  ensureInitialized: vi.fn(),
}))

const mockRenderToBuffer = vi.fn()
vi.mock('@react-pdf/renderer', () => ({
  renderToBuffer: (...args: unknown[]) => mockRenderToBuffer(...args),
  Document: vi.fn(),
  Page: vi.fn(),
  Text: vi.fn(),
  View: vi.fn(),
  StyleSheet: { create: (s: unknown) => s },
}))

vi.mock('@/lib/invoices/pdf-template', () => ({
  InvoicePDF: vi.fn().mockReturnValue('mock-pdf-element'),
}))

const mockSendEmail = vi.fn()
const mockIsConfigured = vi.fn()
vi.mock('@/lib/email/service', () => ({
  getEmailService: () => ({
    sendEmail: (...args: unknown[]) => mockSendEmail(...args),
    isConfigured: () => mockIsConfigured(),
  }),
}))

vi.mock('@/lib/email/invoice-templates', () => ({
  generateInvoiceEmailHtml: vi.fn().mockReturnValue('<html>Invoice</html>'),
  generateInvoiceEmailText: vi.fn().mockReturnValue('Invoice text'),
  generateInvoiceEmailSubject: vi.fn().mockReturnValue('Faktura F-2024001'),
}))

const mockCreateInvoiceJournalEntry = vi.fn()
vi.mock('@/lib/bookkeeping/invoice-entries', () => ({
  createInvoiceJournalEntry: (...args: unknown[]) =>
    mockCreateInvoiceJournalEntry(...args),
}))

import { POST } from '../route'

describe('POST /api/invoices/[id]/send', () => {
  const mockUser = { id: 'user-1', email: 'test@test.se' }
  const customer = makeCustomer({ id: 'cust-1', email: 'kund@test.se' })
  const company = makeCompanySettings({ accounting_method: 'accrual' })
  const invoice = makeInvoice({
    id: 'inv-1',
    status: 'draft',
    customer,
    items: [
      {
        id: 'item-1',
        invoice_id: 'inv-1',
        sort_order: 0,
        description: 'Consulting',
        quantity: 10,
        unit: 'tim',
        unit_price: 1000,
        line_total: 10000,
        vat_rate: 25,
        vat_amount: 2500,
        created_at: '2024-06-15T14:30:00Z',
      },
    ],
  })

  beforeEach(() => {
    vi.clearAllMocks()
    reset()
    eventBus.clear()
    mockSupabase.auth.getUser.mockResolvedValue({ data: { user: mockUser } })
    mockIsConfigured.mockReturnValue(true)
    mockRenderToBuffer.mockResolvedValue(Buffer.from('fake-pdf'))
  })

  it('returns 401 when not authenticated', async () => {
    mockSupabase.auth.getUser.mockResolvedValue({ data: { user: null } })

    const request = createMockRequest('/api/invoices/inv-1/send', { method: 'POST' })
    const response = await POST(request, createMockRouteParams({ id: 'inv-1' }))
    const { status, body } = await parseJsonResponse(response)

    expect(status).toBe(401)
    expect(body).toEqual({ error: 'Unauthorized' })
  })

  it('returns 503 when email service is not configured', async () => {
    mockIsConfigured.mockReturnValue(false)

    const request = createMockRequest('/api/invoices/inv-1/send', { method: 'POST' })
    const response = await POST(request, createMockRouteParams({ id: 'inv-1' }))
    const { status } = await parseJsonResponse(response)

    expect(status).toBe(503)
  })

  it('returns 404 when invoice not found', async () => {
    enqueue({ data: null, error: { message: 'Not found' } })

    const request = createMockRequest('/api/invoices/inv-1/send', { method: 'POST' })
    const response = await POST(request, createMockRouteParams({ id: 'inv-1' }))
    const { status, body } = await parseJsonResponse<{ error: string }>(response)

    expect(status).toBe(404)
    expect(body.error).toBe('Fakturan hittades inte')
  })

  it('returns 400 when customer has no email', async () => {
    const noEmailInvoice = makeInvoice({
      id: 'inv-1',
      customer: makeCustomer({ email: null }),
      items: [],
    })
    enqueue({ data: noEmailInvoice, error: null })

    const request = createMockRequest('/api/invoices/inv-1/send', { method: 'POST' })
    const response = await POST(request, createMockRouteParams({ id: 'inv-1' }))
    const { status, body } = await parseJsonResponse<{ error: string }>(response)

    expect(status).toBe(400)
    expect(body.error).toContain('e-postadress')
  })

  it('returns 404 when company settings not found', async () => {
    enqueue({ data: invoice, error: null })
    enqueue({ data: null, error: { message: 'Not found' } })

    const request = createMockRequest('/api/invoices/inv-1/send', { method: 'POST' })
    const response = await POST(request, createMockRouteParams({ id: 'inv-1' }))
    const { status, body } = await parseJsonResponse<{ error: string }>(response)

    expect(status).toBe(404)
    expect(body.error).toBe('Företagsinställningar saknas')
  })

  it('sends invoice email, updates status, creates journal entry for accrual', async () => {
    // Fetch invoice
    enqueue({ data: invoice, error: null })
    // Fetch company settings
    enqueue({ data: company, error: null })

    mockSendEmail.mockResolvedValue({ success: true, messageId: 'msg-1' })
    mockCreateInvoiceJournalEntry.mockResolvedValue({ id: 'je-1' })

    // Update invoice status to 'sent'
    enqueue({ data: null, error: null })
    // Update invoice with journal_entry_id
    enqueue({ data: null, error: null })

    const emitSpy = vi.spyOn(eventBus, 'emit')

    const request = createMockRequest('/api/invoices/inv-1/send', { method: 'POST' })
    const response = await POST(request, createMockRouteParams({ id: 'inv-1' }))
    const { status, body } = await parseJsonResponse<{
      success: boolean
      messageId: string
    }>(response)

    expect(status).toBe(200)
    expect(body.success).toBe(true)
    expect(body.messageId).toBe('msg-1')
    expect(mockSendEmail).toHaveBeenCalledWith(
      expect.objectContaining({
        to: 'kund@test.se',
        subject: 'Faktura F-2024001',
      })
    )
    expect(mockCreateInvoiceJournalEntry).toHaveBeenCalledWith(
      expect.anything(),
      'user-1',
      expect.objectContaining({ id: 'inv-1' }),
      'enskild_firma'
    )
    expect(emitSpy).toHaveBeenCalledWith(
      expect.objectContaining({ type: 'invoice.sent' })
    )
  })

  it('skips journal entry for cash method', async () => {
    const cashCompany = makeCompanySettings({ accounting_method: 'cash' })
    enqueue({ data: invoice, error: null })
    enqueue({ data: cashCompany, error: null })

    mockSendEmail.mockResolvedValue({ success: true, messageId: 'msg-2' })

    // Update invoice status
    enqueue({ data: null, error: null })

    const request = createMockRequest('/api/invoices/inv-1/send', { method: 'POST' })
    const response = await POST(request, createMockRouteParams({ id: 'inv-1' }))
    const { status, body } = await parseJsonResponse<{ success: boolean }>(response)

    expect(status).toBe(200)
    expect(body.success).toBe(true)
    expect(mockCreateInvoiceJournalEntry).not.toHaveBeenCalled()
  })

  it('does not fail when journal entry creation fails (non-blocking)', async () => {
    enqueue({ data: invoice, error: null })
    enqueue({ data: company, error: null })

    mockSendEmail.mockResolvedValue({ success: true, messageId: 'msg-3' })
    mockCreateInvoiceJournalEntry.mockRejectedValue(new Error('Period locked'))

    // Update invoice status
    enqueue({ data: null, error: null })

    const request = createMockRequest('/api/invoices/inv-1/send', { method: 'POST' })
    const response = await POST(request, createMockRouteParams({ id: 'inv-1' }))
    const { status, body } = await parseJsonResponse<{ success: boolean }>(response)

    expect(status).toBe(200)
    expect(body.success).toBe(true)
  })

  it('returns 500 when email sending fails', async () => {
    enqueue({ data: invoice, error: null })
    enqueue({ data: company, error: null })

    mockSendEmail.mockResolvedValue({ success: false, error: 'SMTP error' })

    const request = createMockRequest('/api/invoices/inv-1/send', { method: 'POST' })
    const response = await POST(request, createMockRouteParams({ id: 'inv-1' }))
    const { status, body } = await parseJsonResponse<{ error: string }>(response)

    expect(status).toBe(500)
    expect(body.error).toContain('SMTP error')
  })
})