import {
  OAuthService,
  googleAuth,
  githubAuth,
  handleGoogleCallback,
  handleGithubCallback,
} from '../oauth';
import { authService } from '../auth/auth.service';
import { MockNavigationService } from '../navigation/navigation.interface';

// Mock dependencies
jest.mock('../auth/auth.service', () => ({
  authService: {
    loginWithOAuth: jest.fn(),
  },
}));

// Mock crypto API
const mockRandomUUID = jest.fn();
Object.defineProperty(global, 'crypto', {
  value: {
    randomUUID: mockRandomUUID,
  },
  writable: true,
});

// Mock localStorage
const mockLocalStorage = {
  getItem: jest.fn(),
  setItem: jest.fn(),
  removeItem: jest.fn(),
  clear: jest.fn(),
};
Object.defineProperty(global, 'localStorage', {
  value: mockLocalStorage,
  writable: true,
});

// Mock URL constructor
const mockURL = jest.fn();
Object.defineProperty(global, 'URL', {
  value: mockURL,
  writable: true,
});

describe('OAuth Service', () => {
  let mockNavigation: MockNavigationService;
  let oauthService: OAuthService;

  beforeEach(() => {
    jest.clearAllMocks();
    mockRandomUUID.mockReturnValue('mock-uuid-12345');
    mockLocalStorage.getItem.mockReturnValue(null);

    // Create mock navigation service
    mockNavigation = new MockNavigationService();
    oauthService = new OAuthService(mockNavigation);

    // Reset URL mock
    mockURL.mockClear();
  });

  describe('googleAuth', () => {
    test('should generate state and redirect to Google OAuth URL', () => {
      // Mock URL constructor to return a mock object
      const mockUrlInstance = {
        toString: jest
          .fn()
          .mockReturnValue(
            'https://accounts.google.com/o/oauth2/v2/auth?client_id=mock_google_client_id&response_type=code&scope=openid%20email%20profile&redirect_uri=http%3A%2F%2Flocalhost%3A3000%2Fauth%2Fcallback&state=mock-uuid-12345'
          ),
        searchParams: {
          append: jest.fn(),
        },
      };
      mockURL.mockReturnValue(mockUrlInstance);

      oauthService.googleAuth();

      expect(mockRandomUUID).toHaveBeenCalled();
      expect(mockLocalStorage.setItem).toHaveBeenCalledWith(
        'oauth_state',
        'mock-uuid-12345'
      );
      expect(mockURL).toHaveBeenCalledWith(
        'https://accounts.google.com/o/oauth2/v2/auth'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'client_id',
        'mock_google_client_id'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'response_type',
        'code'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'scope',
        'openid email profile'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'redirect_uri',
        'http://localhost:3000/auth/callback'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'state',
        'mock-uuid-12345'
      );
      expect(mockNavigation.getLastRedirect()).toBe(
        'https://accounts.google.com/o/oauth2/v2/auth?client_id=mock_google_client_id&response_type=code&scope=openid%20email%20profile&redirect_uri=http%3A%2F%2Flocalhost%3A3000%2Fauth%2Fcallback&state=mock-uuid-12345'
      );
    });

    test('should generate unique state for each call', () => {
      const mockUrlInstance = {
        toString: jest.fn().mockReturnValue('https://mock-url.com'),
        searchParams: {
          append: jest.fn(),
        },
      };
      mockURL.mockReturnValue(mockUrlInstance);

      // First call
      mockRandomUUID.mockReturnValueOnce('state-1');
      oauthService.googleAuth();

      // Second call
      mockRandomUUID.mockReturnValueOnce('state-2');
      oauthService.googleAuth();

      expect(mockLocalStorage.setItem).toHaveBeenNthCalledWith(
        1,
        'oauth_state',
        'state-1'
      );
      expect(mockLocalStorage.setItem).toHaveBeenNthCalledWith(
        2,
        'oauth_state',
        'state-2'
      );
    });
  });

  describe('githubAuth', () => {
    test('should generate state and redirect to GitHub OAuth URL', () => {
      // Mock URL constructor to return a mock object
      const mockUrlInstance = {
        toString: jest
          .fn()
          .mockReturnValue(
            'https://github.com/login/oauth/authorize?client_id=mock_github_client_id&response_type=code&scope=user%3Aemail&redirect_uri=http%3A%2F%2Flocalhost%3A3000%2Fauth%2Fcallback&state=mock-uuid-12345'
          ),
        searchParams: {
          append: jest.fn(),
        },
      };
      mockURL.mockReturnValue(mockUrlInstance);

      oauthService.githubAuth();

      expect(mockRandomUUID).toHaveBeenCalled();
      expect(mockLocalStorage.setItem).toHaveBeenCalledWith(
        'oauth_state',
        'mock-uuid-12345'
      );
      expect(mockURL).toHaveBeenCalledWith(
        'https://github.com/login/oauth/authorize'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'client_id',
        'mock_github_client_id'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'response_type',
        'code'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'scope',
        'user:email'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'redirect_uri',
        'http://localhost:3000/auth/callback'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'state',
        'mock-uuid-12345'
      );
      expect(mockNavigation.getLastRedirect()).toBe(
        'https://github.com/login/oauth/authorize?client_id=mock_github_client_id&response_type=code&scope=user%3Aemail&redirect_uri=http%3A%2F%2Flocalhost%3A3000%2Fauth%2Fcallback&state=mock-uuid-12345'
      );
    });

    test('should generate unique state for each call', () => {
      const mockUrlInstance = {
        toString: jest.fn().mockReturnValue('https://mock-url.com'),
        searchParams: {
          append: jest.fn(),
        },
      };
      mockURL.mockReturnValue(mockUrlInstance);

      // First call
      mockRandomUUID.mockReturnValueOnce('state-1');
      oauthService.githubAuth();

      // Second call
      mockRandomUUID.mockReturnValueOnce('state-2');
      oauthService.githubAuth();

      expect(mockLocalStorage.setItem).toHaveBeenNthCalledWith(
        1,
        'oauth_state',
        'state-1'
      );
      expect(mockLocalStorage.setItem).toHaveBeenNthCalledWith(
        2,
        'oauth_state',
        'state-2'
      );
    });
  });

  describe('handleGoogleCallback', () => {
    beforeEach(() => {
      // Set up mock navigation with callback parameters
      mockNavigation.setSearchParams('?code=auth-code&state=stored-state');
    });

    test('should successfully handle Google OAuth callback', async () => {
      mockLocalStorage.getItem.mockReturnValue('stored-state');

      // Mock the UUIDs that will be generated for token and user info
      mockRandomUUID
        .mockReturnValueOnce('mock-token-uuid')
        .mockReturnValueOnce('mock-user-uuid');

      (authService.loginWithOAuth as jest.Mock).mockResolvedValue({
        user: { id: '123', email: 'google@example.com' },
        accessToken: 'oauth_google_token_123456789',
        refreshToken: 'oauth_google_refresh_123456789',
      });

      const result = await oauthService.handleGoogleCallback();

      expect(authService.loginWithOAuth).toHaveBeenCalledWith('google', {
        email: 'mock_google_user_mock-user-uuid@example.com',
        username: 'Mock Google User',
      });
      expect(mockLocalStorage.removeItem).toHaveBeenCalledWith('oauth_state');
      expect(result).toEqual({
        user: { id: '123', email: 'google@example.com' },
        accessToken: 'oauth_google_token_123456789',
        refreshToken: 'oauth_google_refresh_123456789',
      });
    });

    test('should throw error when state does not match', async () => {
      mockLocalStorage.getItem.mockReturnValue('stored-state');
      mockNavigation.setSearchParams('?code=auth-code&state=different-state');

      await expect(oauthService.handleGoogleCallback()).rejects.toThrow(
        'Invalid OAuth state'
      );
      expect(authService.loginWithOAuth).not.toHaveBeenCalled();
    });

    test('should throw error when no stored state exists', async () => {
      mockLocalStorage.getItem.mockReturnValue(null);
      mockNavigation.setSearchParams('?code=auth-code&state=some-state');

      await expect(oauthService.handleGoogleCallback()).rejects.toThrow(
        'Invalid OAuth state'
      );
    });

    test('should handle missing code parameter gracefully', async () => {
      mockLocalStorage.getItem.mockReturnValue('stored-state');
      mockNavigation.setSearchParams('?state=stored-state');

      // Mock the UUIDs for token exchange
      mockRandomUUID
        .mockReturnValueOnce('mock-token-uuid')
        .mockReturnValueOnce('mock-user-uuid');

      (authService.loginWithOAuth as jest.Mock).mockResolvedValue({
        user: { id: '123', email: 'google@example.com' },
        accessToken: 'oauth_google_token_123456789',
        refreshToken: 'oauth_google_refresh_123456789',
      });

      // The OAuth service handles null code by passing it to mock functions
      const result = await oauthService.handleGoogleCallback();
      expect(result).toBeDefined();
      expect(authService.loginWithOAuth).toHaveBeenCalled();
    });
  });

  describe('handleGithubCallback', () => {
    beforeEach(() => {
      // Set up mock navigation with callback parameters
      mockNavigation.setSearchParams('?code=auth-code&state=stored-state');
    });

    test('should successfully handle GitHub OAuth callback', async () => {
      mockLocalStorage.getItem.mockReturnValue('stored-state');

      // Mock the UUIDs that will be generated for token and user info
      mockRandomUUID
        .mockReturnValueOnce('mock-token-uuid')
        .mockReturnValueOnce('mock-user-uuid');

      (authService.loginWithOAuth as jest.Mock).mockResolvedValue({
        user: { id: '456', email: 'github@example.com' },
        accessToken: 'oauth_github_token_123456789',
        refreshToken: 'oauth_github_refresh_123456789',
      });

      const result = await oauthService.handleGithubCallback();

      expect(authService.loginWithOAuth).toHaveBeenCalledWith('github', {
        email: 'mock_github_user_mock-user-uuid@example.com',
        username: 'Mock Github User',
      });
      expect(result).toEqual({
        user: { id: '456', email: 'github@example.com' },
        accessToken: 'oauth_github_token_123456789',
        refreshToken: 'oauth_github_refresh_123456789',
      });
    });

    test('should throw error when state validation fails', async () => {
      mockLocalStorage.getItem.mockReturnValue('stored-state');
      mockNavigation.setSearchParams('?code=auth-code&state=wrong-state');

      await expect(oauthService.handleGithubCallback()).rejects.toThrow(
        'Invalid OAuth state'
      );
    });
  });

  describe('state management', () => {
    test('should clear OAuth state after successful callback', async () => {
      mockLocalStorage.getItem.mockReturnValue('test-state');
      mockNavigation.setSearchParams('?code=auth-code&state=test-state');

      // Mock UUIDs for the mock functions
      mockRandomUUID
        .mockReturnValueOnce('mock-token-uuid')
        .mockReturnValueOnce('mock-user-uuid');

      (authService.loginWithOAuth as jest.Mock).mockResolvedValue({
        user: {},
        accessToken: 'token',
        refreshToken: 'refresh',
      });

      await oauthService.handleGoogleCallback();

      expect(mockLocalStorage.removeItem).toHaveBeenCalledWith('oauth_state');
    });

    test('should not clear state on validation failure', async () => {
      mockLocalStorage.getItem.mockReturnValue('stored-state');
      mockNavigation.setSearchParams('?code=auth-code&state=wrong-state');

      try {
        await oauthService.handleGoogleCallback();
      } catch (_error) {
        // Expected to throw
      }

      expect(mockLocalStorage.removeItem).not.toHaveBeenCalled();
    });
  });

  describe('mock token exchange', () => {
    test('should generate unique mock access tokens', async () => {
      mockLocalStorage.getItem.mockReturnValue('test-state');

      // First callback
      mockNavigation.setSearchParams('?code=code1&state=test-state');

      // Mock different UUID values for token generation
      mockRandomUUID
        .mockReturnValueOnce('token-1')
        .mockReturnValueOnce('user-1');

      (authService.loginWithOAuth as jest.Mock).mockResolvedValueOnce({
        user: {},
        accessToken: 'oauth_google_token_1',
        refreshToken: 'oauth_google_refresh_1',
      });

      const result1 = await oauthService.handleGoogleCallback();

      // Second callback
      mockNavigation.setSearchParams('?code=code2&state=test-state');
      mockLocalStorage.getItem.mockReturnValue('test-state');

      mockRandomUUID
        .mockReturnValueOnce('token-2')
        .mockReturnValueOnce('user-2');

      (authService.loginWithOAuth as jest.Mock).mockResolvedValueOnce({
        user: {},
        accessToken: 'oauth_google_token_2',
        refreshToken: 'oauth_google_refresh_2',
      });

      const result2 = await oauthService.handleGoogleCallback();

      expect(result1.accessToken).not.toBe(result2.accessToken);
      expect(result1.refreshToken).not.toBe(result2.refreshToken);
    });
  });

  describe('mock user info generation', () => {
    test('should generate provider-specific user info', async () => {
      mockLocalStorage.getItem.mockReturnValue('test-state');

      // Test Google callback
      mockNavigation.setSearchParams('?code=google-code&state=test-state');

      mockRandomUUID
        .mockReturnValueOnce('google-token')
        .mockReturnValueOnce('google-user');

      (authService.loginWithOAuth as jest.Mock).mockResolvedValue({
        user: { provider: 'google', email: 'google@example.com' },
        accessToken: 'google-token',
        refreshToken: 'google-refresh',
      });

      await oauthService.handleGoogleCallback();

      // Check that the correct user info was passed to loginWithOAuth
      const googleCall = (authService.loginWithOAuth as jest.Mock).mock
        .calls[0];
      expect(googleCall[0]).toBe('google');
      expect(googleCall[1].username).toBe('Mock Google User');
      expect(googleCall[1].email).toContain('mock_google_user_');

      // Test GitHub callback
      mockNavigation.setSearchParams('?code=github-code&state=test-state');
      mockLocalStorage.getItem.mockReturnValue('test-state');

      mockRandomUUID
        .mockReturnValueOnce('github-token')
        .mockReturnValueOnce('github-user');

      (authService.loginWithOAuth as jest.Mock).mockResolvedValue({
        user: { provider: 'github', email: 'github@example.com' },
        accessToken: 'github-token',
        refreshToken: 'github-refresh',
      });

      await oauthService.handleGithubCallback();

      // Check that the correct user info was passed to loginWithOAuth
      const githubCall = (authService.loginWithOAuth as jest.Mock).mock
        .calls[1];
      expect(githubCall[0]).toBe('github');
      expect(githubCall[1].username).toBe('Mock Github User');
      expect(githubCall[1].email).toContain('mock_github_user_');
    });
  });

  describe('URL construction', () => {
    test('should properly encode redirect URI in Google auth URL', () => {
      const mockUrlInstance = {
        toString: jest
          .fn()
          .mockReturnValue('https://accounts.google.com/o/oauth2/v2/auth'),
        searchParams: {
          append: jest.fn(),
        },
      };
      mockURL.mockReturnValue(mockUrlInstance);

      oauthService.googleAuth();

      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'redirect_uri',
        'http://localhost:3000/auth/callback'
      );
    });

    test('should properly encode redirect URI in GitHub auth URL', () => {
      const mockUrlInstance = {
        toString: jest
          .fn()
          .mockReturnValue('https://github.com/login/oauth/authorize'),
        searchParams: {
          append: jest.fn(),
        },
      };
      mockURL.mockReturnValue(mockUrlInstance);

      oauthService.githubAuth();

      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'redirect_uri',
        'http://localhost:3000/auth/callback'
      );
    });

    test('should include all required OAuth parameters for Google', () => {
      const mockUrlInstance = {
        toString: jest.fn(),
        searchParams: {
          append: jest.fn(),
        },
      };
      mockURL.mockReturnValue(mockUrlInstance);

      oauthService.googleAuth();

      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'client_id',
        'mock_google_client_id'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'response_type',
        'code'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'scope',
        'openid email profile'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'redirect_uri',
        'http://localhost:3000/auth/callback'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'state',
        'mock-uuid-12345'
      );
    });

    test('should include all required OAuth parameters for GitHub', () => {
      const mockUrlInstance = {
        toString: jest.fn(),
        searchParams: {
          append: jest.fn(),
        },
      };
      mockURL.mockReturnValue(mockUrlInstance);

      oauthService.githubAuth();

      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'client_id',
        'mock_github_client_id'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'response_type',
        'code'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'scope',
        'user:email'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'redirect_uri',
        'http://localhost:3000/auth/callback'
      );
      expect(mockUrlInstance.searchParams.append).toHaveBeenCalledWith(
        'state',
        'mock-uuid-12345'
      );
    });
  });

  describe('backward compatibility', () => {
    test('should support legacy googleAuth function', () => {
      const mockUrlInstance = {
        toString: jest.fn().mockReturnValue('https://google-auth-url.com'),
        searchParams: { append: jest.fn() },
      };
      mockURL.mockReturnValue(mockUrlInstance);

      googleAuth();

      expect(mockLocalStorage.setItem).toHaveBeenCalledWith(
        'oauth_state',
        'mock-uuid-12345'
      );
    });

    test('should support legacy githubAuth function', () => {
      const mockUrlInstance = {
        toString: jest.fn().mockReturnValue('https://github-auth-url.com'),
        searchParams: { append: jest.fn() },
      };
      mockURL.mockReturnValue(mockUrlInstance);

      githubAuth();

      expect(mockLocalStorage.setItem).toHaveBeenCalledWith(
        'oauth_state',
        'mock-uuid-12345'
      );
    });

    test('should support legacy handleGoogleCallback function', async () => {
      mockLocalStorage.getItem.mockReturnValue('test-state');

      // The legacy function uses browser navigation service which reads from window.location
      // We'll test this indirectly by ensuring it uses the same logic as the class method
      mockRandomUUID
        .mockReturnValueOnce('token-uuid')
        .mockReturnValueOnce('user-uuid');

      (authService.loginWithOAuth as jest.Mock).mockResolvedValue({
        user: { id: '123' },
        accessToken: 'token',
        refreshToken: 'refresh',
      });

      // Since we can't easily mock window.location in JSDOM, we'll verify
      // that the legacy functions exist and are callable
      expect(typeof handleGoogleCallback).toBe('function');
      expect(typeof handleGithubCallback).toBe('function');
    });
  });
});