import request from 'supertest';
import express from 'express';
import { createI18nRoutes } from '../../../src/routes/i18n';
import { i18nService } from '../../../src/i18n';

// Mock the i18n service
jest.mock('../../../src/i18n', () => ({
  i18nService: {
    isLocaleSupported: jest.fn(),
    getAvailableLocales: jest.fn(),
    getTranslations: jest.fn(),
    getDefaultLocale: jest.fn(),
    getLocaleDisplayName: jest.fn(),
    detectLocale: jest.fn()
  }
}));

const mockI18nService = i18nService as jest.Mocked<typeof i18nService>;

describe('I18n API Routes', () => {
  let app: express.Application;

  beforeEach(() => {
    app = express();
    app.use('/api/i18n', createI18nRoutes());

    // Reset mocks
    jest.clearAllMocks();
    // Default mock implementations
    mockI18nService.getAvailableLocales.mockReturnValue(['en', 'es-MX']);
    mockI18nService.getDefaultLocale.mockReturnValue('en');
    mockI18nService.getLocaleDisplayName.mockImplementation((locale: string) => {
      const names: Record<string, string> = {
        'en': 'English',
        'es-MX': 'Español (México)'
      };
      return names[locale] || locale;
    });
  });

  describe('GET /api/i18n/:locale', () => {
    const mockTranslations = {
      common: {
        appName: 'Great Lakes Ice Report',
        submit: 'Submit',
        cancel: 'Cancel'
      },
      pages: {
        home: {
          title: 'Ice Report',
          subtitle: 'Community winter road conditions'
        }
      }
    };

    it('should return translations for a supported locale', async () => {
      mockI18nService.isLocaleSupported.mockReturnValue(true);
      mockI18nService.getTranslations.mockReturnValue(mockTranslations);

      const response = await request(app)
        .get('/api/i18n/en')
        .expect(200);

      expect(response.headers['cache-control']).toBe('public, max-age=3600');
      expect(response.headers['content-type']).toMatch(/application\/json/);
      expect(response.body).toEqual(mockTranslations);
      expect(mockI18nService.isLocaleSupported).toHaveBeenCalledWith('en');
      expect(mockI18nService.getTranslations).toHaveBeenCalledWith('en');
    });

    it('should return translations for Spanish locale', async () => {
      const spanishTranslations = {
        common: {
          appName: 'Reporte de Hielo de los Grandes Lagos',
          submit: 'Enviar',
          cancel: 'Cancelar'
        }
      };

      mockI18nService.isLocaleSupported.mockReturnValue(true);
      mockI18nService.getTranslations.mockReturnValue(spanishTranslations);

      const response = await request(app)
        .get('/api/i18n/es-MX')
        .expect(200);

      expect(response.body).toEqual(spanishTranslations);
      expect(mockI18nService.isLocaleSupported).toHaveBeenCalledWith('es-MX');
      expect(mockI18nService.getTranslations).toHaveBeenCalledWith('es-MX');
    });

    it('should reject unsupported locale', async () => {
      mockI18nService.isLocaleSupported.mockReturnValue(false);

      const response = await request(app)
        .get('/api/i18n/fr')
        .expect(400);

      expect(response.body).toEqual({
        error: 'Unsupported locale',
        supportedLocales: ['en', 'es-MX']
      });
      expect(mockI18nService.isLocaleSupported).toHaveBeenCalledWith('fr');
      expect(mockI18nService.getAvailableLocales).toHaveBeenCalled();
      expect(mockI18nService.getTranslations).not.toHaveBeenCalled();
    });

    it('should handle missing translations for supported locale', async () => {
      mockI18nService.isLocaleSupported.mockReturnValue(true);
      mockI18nService.getTranslations.mockReturnValue(null);

      const response = await request(app)
        .get('/api/i18n/en')
        .expect(404);

      expect(response.body).toEqual({
        error: 'Translations not found for locale',
        locale: 'en'
      });
      expect(mockI18nService.getTranslations).toHaveBeenCalledWith('en');
    });

    it('should handle special characters in locale parameter', async () => {
      mockI18nService.isLocaleSupported.mockReturnValue(false);

      await request(app)
        .get('/api/i18n/en-US@currency=USD')
        .expect(400);

      expect(mockI18nService.isLocaleSupported).toHaveBeenCalledWith('en-US@currency=USD');
    });

    it('should handle empty locale parameter', async () => {
      mockI18nService.isLocaleSupported.mockReturnValue(false);

      await request(app)
        .get('/api/i18n/')
        .expect(200); // This will hit the GET / route instead

      expect(mockI18nService.isLocaleSupported).not.toHaveBeenCalled();
    });
  });

  describe('GET /api/i18n', () => {
    it('should return available locales with display names', async () => {
      const response = await request(app)
        .get('/api/i18n')
        .expect(200);

      expect(response.body).toEqual({
        default: 'en',
        available: [
          { code: 'en', name: 'English' },
          { code: 'es-MX', name: 'Español (México)' }
        ]
      });

      expect(mockI18nService.getAvailableLocales).toHaveBeenCalled();
      expect(mockI18nService.getDefaultLocale).toHaveBeenCalled();
      expect(mockI18nService.getLocaleDisplayName).toHaveBeenCalledWith('en');
      expect(mockI18nService.getLocaleDisplayName).toHaveBeenCalledWith('es-MX');
    });

    it('should handle empty available locales', async () => {
      mockI18nService.getAvailableLocales.mockReturnValue([]);

      const response = await request(app)
        .get('/api/i18n')
        .expect(200);

      expect(response.body).toEqual({
        default: 'en',
        available: []
      });
    });

    it('should handle missing display names gracefully', async () => {
      mockI18nService.getAvailableLocales.mockReturnValue(['unknown']);
      mockI18nService.getLocaleDisplayName.mockReturnValue('unknown');

      const response = await request(app)
        .get('/api/i18n')
        .expect(200);

      expect(response.body.available).toEqual([
        { code: 'unknown', name: 'unknown' }
      ]);
    });
  });

  describe('GET /api/i18n/detect', () => {
    it('should detect locale from Accept-Language header', async () => {
      mockI18nService.detectLocale.mockReturnValue('es-MX');

      const response = await request(app)
        .get('/api/i18n/detect')
        .set('Accept-Language', 'es-MX,es;q=0.9,en;q=0.8')
        .expect(200);

      expect(response.body).toEqual({
        detected: 'es-MX',
        displayName: 'Español (México)'
      });

      expect(mockI18nService.detectLocale).toHaveBeenCalledWith('es-MX,es;q=0.9,en;q=0.8');
      expect(mockI18nService.getLocaleDisplayName).toHaveBeenCalledWith('es-MX');
    });

    it('should handle missing Accept-Language header', async () => {
      mockI18nService.detectLocale.mockReturnValue('en');

      const response = await request(app)
        .get('/api/i18n/detect')
        .expect(200);

      expect(response.body).toEqual({
        detected: 'en',
        displayName: 'English'
      });

      expect(mockI18nService.detectLocale).toHaveBeenCalledWith(undefined);
    });

    it('should handle complex Accept-Language header', async () => {
      mockI18nService.detectLocale.mockReturnValue('en');

      const response = await request(app)
        .get('/api/i18n/detect')
        .set('Accept-Language', 'fr-FR,fr;q=0.9,en-US;q=0.8,en;q=0.7,*;q=0.5')
        .expect(200);

      expect(response.body.detected).toBe('en');
      expect(mockI18nService.detectLocale).toHaveBeenCalledWith('fr-FR,fr;q=0.9,en-US;q=0.8,en;q=0.7,*;q=0.5');
    });

    it('should handle malformed Accept-Language header', async () => {
      mockI18nService.detectLocale.mockReturnValue('en');

      const response = await request(app)
        .get('/api/i18n/detect')
        .set('Accept-Language', 'invalid;;;malformed,,,')
        .expect(200);

      expect(response.body.detected).toBe('en');
      expect(mockI18nService.detectLocale).toHaveBeenCalledWith('invalid;;;malformed,,,');
    });

    it('should handle empty Accept-Language header', async () => {
      mockI18nService.detectLocale.mockReturnValue('en');

      const response = await request(app)
        .get('/api/i18n/detect')
        .set('Accept-Language', '')
        .expect(200);

      expect(response.body.detected).toBe('en');
      expect(mockI18nService.detectLocale).toHaveBeenCalledWith('');
    });
  });

  describe('Route ordering and conflicts', () => {
    it('should prioritize specific routes over detect route', async () => {
      // Test that /api/i18n/detect doesn't conflict with /api/i18n/:locale
      mockI18nService.detectLocale.mockReturnValue('en');

      const response = await request(app)
        .get('/api/i18n/detect')
        .expect(200);

      expect(response.body).toHaveProperty('detected');
      expect(response.body).toHaveProperty('displayName');
      expect(mockI18nService.detectLocale).toHaveBeenCalled();
    });

    it('should handle locale named "detect" correctly', async () => {
      // This should NOT call the detect endpoint
      mockI18nService.isLocaleSupported.mockReturnValue(false);

      await request(app)
        .get('/api/i18n/detect')
        .expect(200); // This hits the detect route, not the locale route

      expect(mockI18nService.isLocaleSupported).not.toHaveBeenCalled();
      expect(mockI18nService.detectLocale).toHaveBeenCalled();
    });
  });

  describe('HTTP headers and content type', () => {
    it('should set correct content-type for translations', async () => {
      mockI18nService.isLocaleSupported.mockReturnValue(true);
      mockI18nService.getTranslations.mockReturnValue({ test: 'data' });

      const response = await request(app)
        .get('/api/i18n/en')
        .expect(200);

      expect(response.headers['content-type']).toMatch(/application\/json/);
    });

    it('should set cache headers for translations', async () => {
      mockI18nService.isLocaleSupported.mockReturnValue(true);
      mockI18nService.getTranslations.mockReturnValue({ test: 'data' });

      const response = await request(app)
        .get('/api/i18n/en')
        .expect(200);

      expect(response.headers['cache-control']).toBe('public, max-age=3600');
    });

    it('should not set cache headers for error responses', async () => {
      mockI18nService.isLocaleSupported.mockReturnValue(false);

      const response = await request(app)
        .get('/api/i18n/invalid')
        .expect(400);

      expect(response.headers['cache-control']).toBeUndefined();
    });
  });
});