/**
 * Unit tests for Contact API route
 * These tests focus on testing the business logic without complex mocking
 */
import { POST } from './route'

const mockInsertOne = jest.fn()

// Mock the logger to avoid complex setup
jest.mock('@/lib/logger', () => ({
  createComponentLogger: () => ({
    info: jest.fn(),
    error: jest.fn(),
    warn: jest.fn(),
  })
}))

jest.mock('@/lib/mongodb', () => ({
  getCollection: jest.fn(async () => ({ insertOne: mockInsertOne })),
}))

describe('/api/contact Unit Tests', () => {
  beforeEach(() => {
    mockInsertOne.mockReset()
  })

  describe('MongoDB persistence', () => {
    const validData = {
      name: 'Test User',
      email: 'test@example.com',
      subject: 'Test Subject',
      message: 'This is a test message with enough content',
      gdprConsent: true,
    }

    it('persists a valid submission before reporting success', async () => {
      mockInsertOne.mockResolvedValue({ insertedId: { toHexString: () => 'submission-123' } })
      const request = {
        headers: new Headers({ 'x-forwarded-for': 'persistence-success' }),
        json: async () => validData,
      } as any

      const response = await POST(request)
      const body = await response.json()

      expect(response.status).toBe(200)
      expect(body.submissionId).toBe('submission-123')
      expect(mockInsertOne).toHaveBeenCalledWith(expect.objectContaining({
        ...validData,
        status: 'new',
        createdAt: expect.any(Date),
      }))
    })

    it('returns a server error when persistence fails', async () => {
      mockInsertOne.mockRejectedValue(new Error('MongoDB unavailable'))
      const request = {
        headers: new Headers({ 'x-forwarded-for': 'persistence-failure' }),
        json: async () => validData,
      } as any

      const response = await POST(request)

      expect(response.status).toBe(500)
      expect(mockInsertOne).toHaveBeenCalledTimes(1)
    })

    it('rejects an over-long message before persisting', async () => {
      const longMessage = { ...validData, message: 'x'.repeat(5001) }
      const request = {
        headers: new Headers({ 'x-forwarded-for': 'too-long' }),
        json: async () => longMessage,
      } as any

      const response = await POST(request)

      expect(response.status).toBe(400)
      expect(mockInsertOne).not.toHaveBeenCalled()
    })
  })

  // TC-001: Email Format Validation Test (ZEE-48)
  describe('Input validation logic', () => {
    it('should validate required fields', () => {
      const validData = {
        name: 'Test User',
        email: 'test@example.com',
        subject: 'Test Subject',
        message: 'This is a test message with enough content',
        gdprConsent: true
      }

      // Test individual field validation logic
      expect(validData.name.length).toBeGreaterThan(1)
      expect(validData.email).toMatch(/^[^\s@]+@[^\s@]+\.[^\s@]+$/)
      expect(validData.subject.length).toBeGreaterThan(2)
      expect(validData.message.length).toBeGreaterThan(9)
      expect(validData.gdprConsent).toBe(true)
    })

    it('TC-001: should detect invalid email formats', () => {
      const invalidEmails = [
        'invalid-email',
        'test@',
        '@example.com',
        'test.example.com',
        ''
      ]

      const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/

      invalidEmails.forEach(email => {
        expect(email).not.toMatch(emailRegex)
      })
    })

    it('should validate field lengths', () => {
      const testCases = [
        { field: 'name', value: 'T', minLength: 2, valid: false },
        { field: 'name', value: 'Test User', minLength: 2, valid: true },
        { field: 'subject', value: 'Te', minLength: 3, valid: false },
        { field: 'subject', value: 'Test Subject', minLength: 3, valid: true },
        { field: 'message', value: 'Short', minLength: 10, valid: false },
        { field: 'message', value: 'This is a longer message', minLength: 10, valid: true }
      ]

      testCases.forEach(testCase => {
        const isValid = testCase.value.length >= testCase.minLength
        expect(isValid).toBe(testCase.valid)
      })
    })
  })

  describe('Spam detection logic', () => {
    it('should detect spam keywords', () => {
      const spamKeywords = [
        'free money', 'click here', 'buy now', 'urgent business',
        'viagra', 'cheap', 'limited time', 'act now'
      ]

      const spamText = 'FREE MONEY CLICK HERE NOW BUY VIAGRA CHEAP URGENT BUSINESS PROPOSAL'
      
      let spamCount = 0
      spamKeywords.forEach(keyword => {
        if (spamText.toLowerCase().includes(keyword.toLowerCase())) {
          spamCount++
        }
      })

      // Should detect multiple spam keywords
      expect(spamCount).toBeGreaterThan(3)
    })

    it('should allow legitimate business content', () => {
      const legitimateText = 'Hello, I would like to buy your web hosting service. Can you provide more information about your business offerings?'
      
      const spamKeywords = [
        'free money', 'click here now', 'urgent business proposal',
        'viagra', 'cheap pills', 'limited time offer'
      ]

      let spamCount = 0
      spamKeywords.forEach(keyword => {
        if (legitimateText.toLowerCase().includes(keyword.toLowerCase())) {
          spamCount++
        }
      })

      // Should not trigger spam detection
      expect(spamCount).toBeLessThan(2)
    })
  })

  describe('Input sanitization logic', () => {
    it('should handle potentially dangerous characters', () => {
      const dangerousInput = '<script>alert("xss")</script>Test User'
      
      // Simple sanitization check - removing script tags
      const sanitized = dangerousInput.replace(/<script[^>]*>.*?<\/script>/gi, '')
      
      expect(sanitized).toBe('Test User')
      expect(sanitized).not.toContain('<script>')
    })

    it('should preserve safe HTML entities', () => {
      const inputWithEntities = 'Test & Company "Quotes" and \'apostrophes\''
      
      // Should preserve normal business text
      expect(inputWithEntities.length).toBeGreaterThan(0)
      expect(inputWithEntities).toContain('&')
      expect(inputWithEntities).toContain('"')
      expect(inputWithEntities).toContain("'")
    })
  })

  describe('Rate limiting logic', () => {
    it('should implement rate limiting concept', () => {
      // Simple rate limiting simulation
      const requests = []
      const timeWindow = 60000 // 1 minute
      const maxRequests = 3

      // Simulate requests
      const now = Date.now()
      requests.push(now)
      requests.push(now + 1000)
      requests.push(now + 2000)
      requests.push(now + 3000) // This should be rate limited

      // Filter requests within time window
      const recentRequests = requests.filter(time => 
        (now + 3000) - time < timeWindow
      )

      expect(recentRequests.length).toBe(4)
      expect(recentRequests.length > maxRequests).toBe(true)
    })
  })

  describe('Response format validation', () => {
    it('should validate success response structure', () => {
      const successResponse = {
        message: 'Üzenet sikeresen elküldve!',
        timestamp: new Date().toISOString()
      }

      expect(successResponse).toHaveProperty('message')
      expect(successResponse).toHaveProperty('timestamp')
      expect(typeof successResponse.message).toBe('string')
      expect(typeof successResponse.timestamp).toBe('string')
      expect(() => new Date(successResponse.timestamp)).not.toThrow()
    })

    it('should validate error response structure', () => {
      const errorResponse = {
        error: 'Validációs hiba: hiányzó mezők'
      }

      expect(errorResponse).toHaveProperty('error')
      expect(typeof errorResponse.error).toBe('string')
      expect(errorResponse.error.length).toBeGreaterThan(0)
    })
  })

  describe('Business logic helpers', () => {
    it('should validate GDPR consent requirement', () => {
      const testCases = [
        { gdprConsent: true, valid: true },
        { gdprConsent: false, valid: false },
        { gdprConsent: undefined, valid: false },
        { gdprConsent: null, valid: false }
      ]

      testCases.forEach(testCase => {
        const isValid = testCase.gdprConsent === true
        expect(isValid).toBe(testCase.valid)
      })
    })

    it('should generate proper timestamps', () => {
      const timestamp = new Date().toISOString()
      
      expect(timestamp).toMatch(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z$/)
      expect(() => new Date(timestamp)).not.toThrow()
      
      const parsedDate = new Date(timestamp)
      expect(parsedDate.getTime()).toBeCloseTo(Date.now(), -3) // Within 1 second
    })

    it('should handle IP address extraction logic', () => {
      // Simulate IP extraction from headers
      const mockHeaders = {
        'x-forwarded-for': '192.168.1.100, 10.0.0.1',
        'x-real-ip': '192.168.1.100',
        'remote-addr': '127.0.0.1'
      }

      // Extract first IP from x-forwarded-for
      const forwardedFor = mockHeaders['x-forwarded-for']
      const clientIp = forwardedFor ? forwardedFor.split(',')[0].trim() : mockHeaders['x-real-ip']
      
      expect(clientIp).toBe('192.168.1.100')
    })
  })
})