// Test for path utilities functionality
import fs from 'fs';
import path from 'path';

// Mock fs module
jest.mock('fs');
const mockFs = fs as jest.Mocked<typeof fs>;

describe('Path Utilities Logic', () => {
  beforeEach(() => {
    jest.clearAllMocks();
    delete process.env.MCPHUB_SETTING_PATH;
  });

  // Test the core logic of path resolution
  const findConfigFile = (filename: string): string => {
    const envPath = process.env.MCPHUB_SETTING_PATH;
    const potentialPaths = [
      ...(envPath ? [envPath] : []),
      path.resolve(process.cwd(), filename),
      path.join(process.cwd(), filename),
    ];

    for (const filePath of potentialPaths) {
      if (fs.existsSync(filePath)) {
        return filePath;
      }
    }

    return path.resolve(process.cwd(), filename);
  };

  describe('Configuration File Resolution', () => {
    it('should find existing file in current directory', () => {
      const filename = 'test-config.json';
      const expectedPath = path.resolve(process.cwd(), filename);
      
      mockFs.existsSync.mockImplementation((filePath) => {
        return filePath === expectedPath;
      });

      const result = findConfigFile(filename);

      expect(result).toBe(expectedPath);
      expect(mockFs.existsSync).toHaveBeenCalled();
    });

    it('should prioritize environment variable path', () => {
      const filename = 'test-config.json';
      const envPath = '/custom/path/test-config.json';
      process.env.MCPHUB_SETTING_PATH = envPath;
      
      mockFs.existsSync.mockImplementation((filePath) => {
        return filePath === envPath;
      });

      const result = findConfigFile(filename);

      expect(result).toBe(envPath);
      expect(mockFs.existsSync).toHaveBeenCalledWith(envPath);
    });

    it('should return default path when file does not exist', () => {
      const filename = 'nonexistent-config.json';
      const expectedDefaultPath = path.resolve(process.cwd(), filename);
      
      mockFs.existsSync.mockReturnValue(false);

      const result = findConfigFile(filename);

      expect(result).toBe(expectedDefaultPath);
    });

    it('should handle different file types', () => {
      const testFiles = [
        'config.json',
        'settings.yaml',
        'data.xml',
        'servers.json'
      ];
      
      testFiles.forEach(filename => {
        const expectedPath = path.resolve(process.cwd(), filename);
        
        mockFs.existsSync.mockImplementation((filePath) => {
          return filePath === expectedPath;
        });

        const result = findConfigFile(filename);
        expect(result).toBe(expectedPath);
        expect(path.isAbsolute(result)).toBe(true);
      });
    });
  });

  describe('Path Operations', () => {
    it('should generate absolute paths', () => {
      const filename = 'test.json';
      mockFs.existsSync.mockReturnValue(false);

      const result = findConfigFile(filename);

      expect(path.isAbsolute(result)).toBe(true);
      expect(result).toContain(filename);
    });    it('should handle path normalization', () => {
      const filename = './config/../settings.json';
      
      mockFs.existsSync.mockReturnValue(false);

      const result = findConfigFile(filename);

      expect(typeof result).toBe('string');
      expect(result.length).toBeGreaterThan(0);
    });

    it('should work consistently across multiple calls', () => {
      const filename = 'consistent-test.json';
      const expectedPath = path.resolve(process.cwd(), filename);
      
      mockFs.existsSync.mockImplementation((filePath) => {
        return filePath === expectedPath;
      });

      const result1 = findConfigFile(filename);
      const result2 = findConfigFile(filename);
      
      expect(result1).toBe(result2);
      expect(result1).toBe(expectedPath);
    });
  });

  describe('Environment Variable Handling', () => {
    it('should handle missing environment variable gracefully', () => {
      const filename = 'test.json';
      delete process.env.MCPHUB_SETTING_PATH;
      
      mockFs.existsSync.mockReturnValue(false);

      const result = findConfigFile(filename);

      expect(typeof result).toBe('string');
      expect(result).toContain(filename);
    });

    it('should handle empty environment variable', () => {
      const filename = 'test.json';
      process.env.MCPHUB_SETTING_PATH = '';
      
      mockFs.existsSync.mockReturnValue(false);

      const result = findConfigFile(filename);

      expect(typeof result).toBe('string');
      expect(result).toContain(filename);
    });
  });

  describe('Error Handling', () => {
    it('should handle fs.existsSync errors gracefully', () => {
      const filename = 'test.json';
      
      mockFs.existsSync.mockImplementation(() => {
        throw new Error('File system error');
      });

      expect(() => findConfigFile(filename)).toThrow('File system error');
    });

    it('should validate input parameters', () => {
      const emptyFilename = '';
      
      mockFs.existsSync.mockReturnValue(false);

      const result = findConfigFile(emptyFilename);

      expect(typeof result).toBe('string');
      // Should still return a path, even for empty filename
    });
  });
});
