/**
 * Security Test Suite for FAF MCP
 * Championship-level security validation
 */

import { describe, test, expect } from 'bun:test';
import * as path from 'path';

// Mock file operations for testing
const validatePath = (filePath: string): boolean => {
  // Check for empty path
  if (!filePath || filePath.trim() === '') return false;

  // Check for directory traversal
  if (filePath.includes('..')) return false;

  // Check for absolute paths outside cwd
  const resolved = path.resolve(filePath);
  const cwd = process.cwd();
  if (!resolved.startsWith(cwd)) return false;

  // Check for system directories
  const blocked = ['/etc', '/sys', '/proc', '/dev', '/root'];
  if (blocked.some(dir => resolved.startsWith(dir))) return false;

  return true;
};

const sanitizeInput = (input: string): string => {
  // Remove control characters
  let clean = input.replace(/[\x00-\x1F\x7F]/g, '');

  // Remove potential command injection characters
  clean = clean.replace(/[;&|`$(){}[\]]/g, '');

  return clean;
};

describe('Path Traversal Protection', () => {
  test('should block directory traversal attempts', () => {
    expect(validatePath('../../../etc/passwd')).toBe(false);
    expect(validatePath('../../sensitive.txt')).toBe(false);
    expect(validatePath('./../data')).toBe(false);
  });

  test('should block absolute paths outside working directory', () => {
    expect(validatePath('/etc/passwd')).toBe(false);
    expect(validatePath('/root/.ssh/id_rsa')).toBe(false);
    expect(validatePath('/sys/kernel')).toBe(false);
  });

  test('should allow valid relative paths', () => {
    expect(validatePath('test.txt')).toBe(true);
    expect(validatePath('./data/file.json')).toBe(true);
    expect(validatePath('src/index.ts')).toBe(true);
  });

  test('should handle edge cases', () => {
    expect(validatePath('')).toBe(false);
    expect(validatePath('.')).toBe(true);
    expect(validatePath('./')).toBe(true);
  });
});

describe('Input Sanitization', () => {
  test('should remove control characters', () => {
    expect(sanitizeInput('test\x00file')).toBe('testfile');
    expect(sanitizeInput('data\x1Fvalue')).toBe('datavalue');
  });

  test('should remove command injection characters', () => {
    expect(sanitizeInput('rm -rf /; echo test')).toBe('rm -rf / echo test');
    expect(sanitizeInput('test && malicious')).toBe('test  malicious');
    expect(sanitizeInput('$(whoami)')).toBe('whoami');
  });

  test('should preserve normal text', () => {
    expect(sanitizeInput('normal-file_name.txt')).toBe('normal-file_name.txt');
    expect(sanitizeInput('Score: 88/100')).toBe('Score: 88/100');
  });
});

describe('Resource Limits', () => {
  const MAX_FILE_SIZE = 10 * 1024 * 1024; // 10MB
  const MAX_PATH_LENGTH = 255;
  const OPERATION_TIMEOUT = 5000;

  test('should enforce file size limits', () => {
    const checkFileSize = (size: number) => size <= MAX_FILE_SIZE;

    expect(checkFileSize(1024)).toBe(true); // 1KB
    expect(checkFileSize(5 * 1024 * 1024)).toBe(true); // 5MB
    expect(checkFileSize(11 * 1024 * 1024)).toBe(false); // 11MB
  });

  test('should enforce path length limits', () => {
    const checkPathLength = (p: string) => p.length <= MAX_PATH_LENGTH;

    expect(checkPathLength('normal/path.txt')).toBe(true);
    expect(checkPathLength('a'.repeat(256))).toBe(false);
  });

  test('should enforce operation timeouts', () => {
    const checkTimeout = (duration: number) => duration <= OPERATION_TIMEOUT;

    expect(checkTimeout(100)).toBe(true);
    expect(checkTimeout(5000)).toBe(true);
    expect(checkTimeout(6000)).toBe(false);
  });
});

describe('Error Message Sanitization', () => {
  const sanitizeError = (error: Error): string => {
    let message = error.message;

    // Remove absolute paths
    message = message.replace(/\/[^\s]+/g, '[path]');

    // Remove system information
    message = message.replace(/\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b/g, '[ip]');

    // Remove stack traces
    if (message.includes('at ')) {
      message = message.split('\n')[0];
    }

    return message;
  };

  test('should remove absolute paths from errors', () => {
    const error = new Error('File not found: /Users/username/secret.txt');
    expect(sanitizeError(error)).toBe('File not found: [path]');
  });

  test('should remove IP addresses', () => {
    const error = new Error('Connection failed to 192.168.1.1');
    expect(sanitizeError(error)).toBe('Connection failed to [ip]');
  });

  test('should remove stack traces', () => {
    const error = new Error('Error occurred\n    at function (file.js:10:5)');
    expect(sanitizeError(error)).toBe('Error occurred');
  });
});

describe('MCP Protocol Security', () => {
  test('should validate JSON-RPC messages', () => {
    const isValidMessage = (msg: any): boolean => {
      if (!msg.jsonrpc || msg.jsonrpc !== '2.0') return false;
      if (!msg.method && !msg.id) return false;
      if (msg.params && typeof msg.params !== 'object') return false;
      return true;
    };

    expect(isValidMessage({ jsonrpc: '2.0', method: 'test', id: 1 })).toBe(true);
    expect(isValidMessage({ jsonrpc: '1.0', method: 'test' })).toBe(false);
    expect(isValidMessage({ method: 'test' })).toBe(false);
    expect(isValidMessage({ jsonrpc: '2.0' })).toBe(false);
  });

  test('should limit message size', () => {
    const MAX_MESSAGE_SIZE = 1024 * 1024; // 1MB
    const checkMessageSize = (msg: string) => msg.length <= MAX_MESSAGE_SIZE;

    expect(checkMessageSize('{"test": "data"}')).toBe(true);
    expect(checkMessageSize('x'.repeat(MAX_MESSAGE_SIZE + 1))).toBe(false);
  });
});

// Export test utilities for use in implementation
export { validatePath, sanitizeInput };