import { jest } from '@jest/globals';

// Mock dependencies
jest.unstable_mockModule('../dist/utils/behavioral-detection.js', () => ({
  behavioralDetection: {
    config: { enabled: true, Responses: {} },
    isBlocked: jest.fn(),
    getRateLimit: jest.fn(),
    analyzeRequest: jest.fn()
  }
}));

jest.unstable_mockModule('../dist/utils/network.js', () => ({
  getRealIP: jest.fn()
}));

jest.unstable_mockModule('../dist/utils/logs.js', () => ({
  plugin: jest.fn(),
  error: jest.fn()
}));

// Import the modules after mocking
const BehavioralDetectionMiddleware = (await import('../dist/utils/behavioral-middleware.js')).default;
const { behavioralDetection } = await import('../dist/utils/behavioral-detection.js');
const { getRealIP } = await import('../dist/utils/network.js');
const logs = await import('../dist/utils/logs.js');

describe('Behavioral Middleware', () => {
  let mockReq, mockRes, mockNext;
  let activeTimeouts = [];
  let activeImmediates = [];
  
  // Track async operations for cleanup
  const originalSetTimeout = global.setTimeout;
  const originalSetImmediate = global.setImmediate;
  
  global.setTimeout = (fn, delay, ...args) => {
    const id = originalSetTimeout(fn, delay, ...args);
    activeTimeouts.push(id);
    return id;
  };
  
  global.setImmediate = (fn, ...args) => {
    const id = originalSetImmediate(fn, ...args);
    activeImmediates.push(id);
    return id;
  };

  beforeEach(() => {
    jest.clearAllMocks();
    activeTimeouts = [];
    activeImmediates = [];
    
    // Mock Express request object
    mockReq = {
      url: '/api/test',
      method: 'GET',
      headers: {
        'user-agent': 'test-agent',
        'x-forwarded-for': '192.168.1.1'
      },
      ip: '192.168.1.1'
    };

    // Mock Express response object
    mockRes = {
      statusCode: 200,
      status: jest.fn().mockReturnThis(),
      setHeader: jest.fn().mockReturnThis(),
      end: jest.fn(),
      json: jest.fn(),
      send: jest.fn(),
      locals: {}
    };

    // Mock next function
    mockNext = jest.fn();

    // Default mock returns
    getRealIP.mockReturnValue('192.168.1.1');
    behavioralDetection.isBlocked.mockResolvedValue({ blocked: false });
    behavioralDetection.getRateLimit.mockResolvedValue(null);
    behavioralDetection.analyzeRequest.mockResolvedValue({ totalScore: 0, patterns: [] });
  });

  afterEach(() => {
    // Clear any pending timeouts and immediates
    activeTimeouts.forEach(id => clearTimeout(id));
    activeImmediates.forEach(id => clearImmediate(id));
    activeTimeouts = [];
    activeImmediates = [];
  });

  afterAll(() => {
    // Restore original functions
    global.setTimeout = originalSetTimeout;
    global.setImmediate = originalSetImmediate;
  });

  describe('plugin creation', () => {
    test('should create a behavioral detection middleware plugin', () => {
      const plugin = BehavioralDetectionMiddleware();
      
      expect(plugin.name).toBe('behavioral-detection');
      expect(plugin.priority).toBe(90);
      expect(typeof plugin.middleware).toBe('function');
    });
  });

  describe('middleware execution', () => {
    test('should skip processing when behavioral detection is disabled', async () => {
      behavioralDetection.config.enabled = false;
      const plugin = BehavioralDetectionMiddleware();
      
      await plugin.middleware(mockReq, mockRes, mockNext);
      
      expect(mockNext).toHaveBeenCalled();
      expect(behavioralDetection.isBlocked).not.toHaveBeenCalled();
      
      // Restore enabled state
      behavioralDetection.config.enabled = true;
    });

    test('should process request when behavioral detection is enabled', async () => {
      const plugin = BehavioralDetectionMiddleware();
      
      await plugin.middleware(mockReq, mockRes, mockNext);
      
      expect(mockNext).toHaveBeenCalled();
      expect(getRealIP).toHaveBeenCalledWith(mockReq);
    });

    test('should capture client IP correctly', async () => {
      const plugin = BehavioralDetectionMiddleware();
      getRealIP.mockReturnValue('10.0.0.1');
      
      await plugin.middleware(mockReq, mockRes, mockNext);
      
      expect(getRealIP).toHaveBeenCalledWith(mockReq);
    });
  });

  describe('blocking functionality', () => {
    test('should block requests from blocked IPs', async () => {
      behavioralDetection.isBlocked.mockResolvedValue({
        blocked: true,
        reason: 'Malicious activity detected'
      });

      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      // Trigger response capture by calling end and wait for async processing
      mockRes.end();
      
      // Wait for setImmediate and async processing to complete
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setImmediate(resolve));

      expect(mockRes.status).toHaveBeenCalledWith(403);
      expect(mockRes.setHeader).toHaveBeenCalledWith('X-Behavioral-Block', 'true');
      expect(mockRes.setHeader).toHaveBeenCalledWith('X-Block-Reason', 'Malicious activity detected');
      expect(logs.plugin).toHaveBeenCalledWith('behavioral', expect.stringContaining('Blocked IP'));
    });

    test('should use default block message when none configured', async () => {
      behavioralDetection.isBlocked.mockResolvedValue({
        blocked: true,
        reason: 'Suspicious activity'
      });
      behavioralDetection.config.Responses.BlockMessage = undefined;

      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      mockRes.end();
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setImmediate(resolve));

      expect(mockRes.status).toHaveBeenCalledWith(403);
    });

    test('should handle blocked IP without reason', async () => {
      behavioralDetection.isBlocked.mockResolvedValue({
        blocked: true
      });

      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      mockRes.end();
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setImmediate(resolve));

      expect(mockRes.setHeader).toHaveBeenCalledWith('X-Block-Reason', 'suspicious activity');
    });
  });

  describe('rate limiting functionality', () => {
    test('should apply rate limiting when limit exceeded', async () => {
      // Make sure isBlocked returns false so rate limiting is checked
      behavioralDetection.isBlocked.mockResolvedValue({ blocked: false });
      behavioralDetection.getRateLimit.mockResolvedValue({
        exceeded: true,
        requests: 150,
        limit: 100,
        window: 60000,
        resetTime: Date.now() + 60000
      });

      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      mockRes.end();
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setImmediate(resolve));

      expect(mockRes.status).toHaveBeenCalledWith(429);
      expect(mockRes.setHeader).toHaveBeenCalledWith('X-RateLimit-Limit', '100');
      expect(mockRes.setHeader).toHaveBeenCalledWith('X-RateLimit-Remaining', '0');
      expect(mockRes.setHeader).toHaveBeenCalledWith('Retry-After', '60');
      expect(logs.plugin).toHaveBeenCalledWith('behavioral', expect.stringContaining('Rate limit exceeded'));
    });

    test('should set rate limit headers for non-exceeded limits', async () => {
      behavioralDetection.isBlocked.mockResolvedValue({ blocked: false });
      behavioralDetection.getRateLimit.mockResolvedValue({
        exceeded: false,
        requests: 50,
        limit: 100,
        resetTime: Date.now() + 30000
      });

      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      mockRes.end();
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setImmediate(resolve));

      expect(mockRes.setHeader).toHaveBeenCalledWith('X-RateLimit-Limit', '100');
      expect(mockRes.setHeader).toHaveBeenCalledWith('X-RateLimit-Remaining', '50');
      expect(mockRes.status).not.toHaveBeenCalledWith(429);
    });
  });

  describe('behavioral analysis', () => {
    test('should analyze request and set behavioral headers', async () => {
      behavioralDetection.isBlocked.mockResolvedValue({ blocked: false });
      behavioralDetection.getRateLimit.mockResolvedValue(null);
      behavioralDetection.analyzeRequest.mockResolvedValue({
        totalScore: 25,
        patterns: [
          { name: 'rapid_requests', score: 15 },
          { name: 'suspicious_user_agent', score: 10 }
        ]
      });

      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      mockRes.end();
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setImmediate(resolve));

      expect(behavioralDetection.analyzeRequest).toHaveBeenCalledWith(
        '192.168.1.1',
        mockReq,
        expect.objectContaining({
          status: 200,
          responseTime: expect.any(Number)
        })
      );

      expect(mockRes.setHeader).toHaveBeenCalledWith('X-Behavioral-Score', '25');
      expect(mockRes.setHeader).toHaveBeenCalledWith('X-Behavioral-Patterns', 'rapid_requests, suspicious_user_agent');
    });

    test('should store behavioral signals in response locals', async () => {
      behavioralDetection.isBlocked.mockResolvedValue({ blocked: false });
      behavioralDetection.getRateLimit.mockResolvedValue(null);
      const analysis = {
        totalScore: 10,
        patterns: [{ name: 'test_pattern', score: 10 }]
      };
      behavioralDetection.analyzeRequest.mockResolvedValue(analysis);

      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      mockRes.end();
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setImmediate(resolve));

      expect(mockRes.locals.behavioralSignals).toEqual(analysis);
    });

    test('should not set headers when no patterns detected', async () => {
      behavioralDetection.isBlocked.mockResolvedValue({ blocked: false });
      behavioralDetection.getRateLimit.mockResolvedValue(null);
      behavioralDetection.analyzeRequest.mockResolvedValue({
        totalScore: 0,
        patterns: []
      });

      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      mockRes.end();
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setImmediate(resolve));

      expect(mockRes.setHeader).not.toHaveBeenCalledWith('X-Behavioral-Score', expect.anything());
      expect(mockRes.setHeader).not.toHaveBeenCalledWith('X-Behavioral-Patterns', expect.anything());
    });
  });

  describe('response method interception', () => {
    test('should intercept res.end() calls', async () => {
      const originalEnd = mockRes.end;
      
      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      mockRes.end('test data');

      // Should have called the original method
      expect(originalEnd).toHaveBeenCalledWith('test data');
    });

    test('should intercept res.json() calls', async () => {
      const originalJson = mockRes.json;
      
      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      const testData = { test: 'data' };
      mockRes.json(testData);

      expect(originalJson).toHaveBeenCalledWith(testData);
    });

    test('should intercept res.send() calls', async () => {
      const originalSend = mockRes.send;
      
      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      mockRes.send('test response');

      expect(originalSend).toHaveBeenCalledWith('test response');
    });
  });

  describe('error handling', () => {
    test('should handle errors in behavioral analysis gracefully', async () => {
      behavioralDetection.analyzeRequest.mockRejectedValue(new Error('Analysis failed'));

      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      mockRes.end();
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setTimeout(resolve, 10)); // Give error handling time

      expect(logs.error).toHaveBeenCalledWith('behavioral', expect.stringContaining('Error in behavioral analysis'));
      expect(mockNext).toHaveBeenCalled(); // Should not block request flow
    });

    test('should handle errors in isBlocked check', async () => {
      behavioralDetection.isBlocked.mockRejectedValue(new Error('Block check failed'));

      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      mockRes.end();
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setTimeout(resolve, 10));

      expect(logs.error).toHaveBeenCalledWith('behavioral', expect.stringContaining('Error in behavioral analysis'));
    });

    test('should fail open for availability on errors', async () => {
      behavioralDetection.isBlocked.mockRejectedValue(new Error('Service unavailable'));

      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      expect(mockNext).toHaveBeenCalled();
      // Should not block the request even if behavioral detection fails
    });
  });

  describe('response locals handling', () => {
    test('should handle missing response locals gracefully', async () => {
      delete mockRes.locals;

      const plugin = BehavioralDetectionMiddleware();
      await plugin.middleware(mockReq, mockRes, mockNext);

      mockRes.end();
      await new Promise(resolve => setImmediate(resolve));
      await new Promise(resolve => setImmediate(resolve));

      // Should not throw error even without locals
      expect(mockNext).toHaveBeenCalled();
    });
  });
});