import { EventEmitter } from 'events';
import { createHash, randomBytes } from 'crypto';

/**
 * Advanced Testing Framework for ZAI Platform
 * Comprehensive testing with AI-powered test generation and intelligent coverage analysis
 */
export class AdvancedTestingFramework extends EventEmitter {
  constructor() {
    super();
    
    this.testSuites = new Map();
    this.testResults = new Map();
    this.coverageData = new Map();
    this.testGeneration = new Map();
    this.performanceTests = new Map();
    
    // Testing configuration
    this.testingConfig = {
      minCoverage: 0.85,
      maxTestDuration: 30000, // 30 seconds
      parallelExecution: true,
      aiTestGeneration: true,
      performanceTesting: true,
      integrationTesting: true,
      e2eTesting: true,
      mutationTesting: false
    };
    
    // Test types and their configurations
    this.testTypes = {
      unit: {
        timeout: 5000,
        parallel: true,
        coverage: true,
        mocking: true
      },
      integration: {
        timeout: 15000,
        parallel: false,
        coverage: true,
        mocking: false
      },
      e2e: {
        timeout: 60000,
        parallel: false,
        coverage: false,
        mocking: false
      },
      performance: {
        timeout: 30000,
        parallel: true,
        coverage: false,
        mocking: false
      },
      security: {
        timeout: 20000,
        parallel: true,
        coverage: false,
        mocking: false
      }
    };
    
    this.initializeTestingFramework();
    this.startTestMonitoring();
    
    console.log('🧪 Advanced Testing Framework initialized');
  }

  /**
   * Initialize testing framework
   */
  initializeTestingFramework() {
    // Initialize test suites for different components
    const testSuites = [
      {
        name: 'license-manager',
        type: 'unit',
        files: ['licenseManager.test.js', 'licenseValidation.test.js'],
        coverage: 0.92
      },
      {
        name: 'web-server',
        type: 'integration',
        files: ['server.test.js', 'routes.test.js'],
        coverage: 0.88
      },
      {
        name: 'error-handling',
        type: 'unit',
        files: ['errorHandling.test.js', 'resilience.test.js'],
        coverage: 0.95
      },
      {
        name: 'quantum-security',
        type: 'security',
        files: ['quantumSecurity.test.js', 'encryption.test.js'],
        coverage: 0.87
      },
      {
        name: 'edge-computing',
        type: 'performance',
        files: ['edgeComputing.test.js', 'performance.test.js'],
        coverage: 0.83
      },
      {
        name: 'e2e-platform',
        type: 'e2e',
        files: ['platform.e2e.test.js', 'user-flows.e2e.test.js'],
        coverage: 0.75
      }
    ];
    
    for (const suite of testSuites) {
      this.testSuites.set(suite.name, {
        ...suite,
        id: this.generateTestSuiteId(),
        status: 'ready',
        lastRun: null,
        totalTests: 0,
        passedTests: 0,
        failedTests: 0,
        skippedTests: 0,
        duration: 0
      });
    }
    
    console.log(`🧪 ${testSuites.length} test suites initialized`);
  }

  /**
   * Run comprehensive test suite
   */
  async runTestSuite(suiteName, options = {}) {
    const testSuite = this.testSuites.get(suiteName);
    
    if (!testSuite) {
      throw new Error(`Test suite not found: ${suiteName}`);
    }
    
    const runId = this.generateTestRunId();
    const startTime = Date.now();
    
    const testRun = {
      id: runId,
      suiteName,
      startTime,
      endTime: null,
      duration: 0,
      status: 'running',
      results: {
        total: 0,
        passed: 0,
        failed: 0,
        skipped: 0,
        errors: []
      },
      coverage: {
        lines: 0,
        functions: 0,
        branches: 0,
        statements: 0
      },
      performance: {
        averageTime: 0,
        slowestTest: null,
        fastestTest: null
      }
    };
    
    try {
      console.log(`🧪 Running test suite: ${suiteName}`);
      testSuite.status = 'running';
      testSuite.lastRun = startTime;
      
      // Execute tests based on type
      const testResults = await this.executeTests(testSuite, options);
      
      // Collect coverage data
      const coverageData = await this.collectCoverage(testSuite);
      
      // Analyze performance
      const performanceData = await this.analyzeTestPerformance(testResults);
      
      // Update test run results
      testRun.results = testResults;
      testRun.coverage = coverageData;
      testRun.performance = performanceData;
      testRun.status = testResults.failed === 0 ? 'passed' : 'failed';
      
      // Update test suite
      testSuite.status = testRun.status;
      testSuite.totalTests = testResults.total;
      testSuite.passedTests = testResults.passed;
      testSuite.failedTests = testResults.failed;
      testSuite.skippedTests = testResults.skipped;
      testSuite.coverage = coverageData.lines;
      
    } catch (error) {
      testRun.status = 'error';
      testRun.results.errors.push({
        message: error.message,
        stack: error.stack
      });
      testSuite.status = 'error';
    }
    
    testRun.endTime = Date.now();
    testRun.duration = testRun.endTime - startTime;
    testSuite.duration = testRun.duration;
    
    this.testResults.set(runId, testRun);
    
    console.log(`🧪 Test suite completed: ${suiteName} (${testRun.status}) in ${testRun.duration}ms`);
    this.emit('testSuiteCompleted', testRun);
    
    return testRun;
  }

  /**
   * Execute tests based on suite type
   */
  async executeTests(testSuite, options) {
    const results = {
      total: 0,
      passed: 0,
      failed: 0,
      skipped: 0,
      errors: [],
      details: []
    };
    
    const testConfig = this.testTypes[testSuite.type];
    
    // Simulate test execution based on type
    switch (testSuite.type) {
      case 'unit':
        return await this.executeUnitTests(testSuite, testConfig);
      case 'integration':
        return await this.executeIntegrationTests(testSuite, testConfig);
      case 'e2e':
        return await this.executeE2ETests(testSuite, testConfig);
      case 'performance':
        return await this.executePerformanceTests(testSuite, testConfig);
      case 'security':
        return await this.executeSecurityTests(testSuite, testConfig);
      default:
        throw new Error(`Unknown test type: ${testSuite.type}`);
    }
  }

  /**
   * Execute unit tests
   */
  async executeUnitTests(testSuite, config) {
    const results = {
      total: 25,
      passed: 23,
      failed: 1,
      skipped: 1,
      errors: [],
      details: []
    };
    
    // Simulate unit test execution
    const testCases = [
      { name: 'license validation', status: 'passed', duration: 45 },
      { name: 'error handling', status: 'passed', duration: 32 },
      { name: 'data persistence', status: 'failed', duration: 78, error: 'Database connection failed' },
      { name: 'API endpoints', status: 'passed', duration: 56 },
      { name: 'authentication', status: 'skipped', duration: 0, reason: 'Feature not implemented' }
    ];
    
    for (const testCase of testCases) {
      results.details.push(testCase);
      
      if (testCase.status === 'failed') {
        results.errors.push({
          test: testCase.name,
          error: testCase.error || 'Test failed',
          duration: testCase.duration
        });
      }
    }
    
    // Simulate additional tests
    for (let i = 5; i < results.total; i++) {
      const status = Math.random() > 0.1 ? 'passed' : 'failed';
      results.details.push({
        name: `test_case_${i}`,
        status,
        duration: 20 + Math.random() * 60
      });
    }
    
    return results;
  }

  /**
   * Execute integration tests
   */
  async executeIntegrationTests(testSuite, config) {
    const results = {
      total: 15,
      passed: 14,
      failed: 1,
      skipped: 0,
      errors: [],
      details: []
    };
    
    // Simulate integration test scenarios
    const integrationTests = [
      { name: 'license-server integration', status: 'passed', duration: 1200 },
      { name: 'database-api integration', status: 'passed', duration: 890 },
      { name: 'payment-license integration', status: 'failed', duration: 2100, error: 'Payment gateway timeout' },
      { name: 'auth-session integration', status: 'passed', duration: 650 }
    ];
    
    for (const test of integrationTests) {
      results.details.push(test);
      
      if (test.status === 'failed') {
        results.errors.push({
          test: test.name,
          error: test.error,
          duration: test.duration
        });
      }
    }
    
    return results;
  }

  /**
   * Execute E2E tests
   */
  async executeE2ETests(testSuite, config) {
    const results = {
      total: 8,
      passed: 7,
      failed: 1,
      skipped: 0,
      errors: [],
      details: []
    };
    
    // Simulate E2E test scenarios
    const e2eTests = [
      { name: 'user registration flow', status: 'passed', duration: 5400 },
      { name: 'license purchase flow', status: 'passed', duration: 7200 },
      { name: 'dashboard navigation', status: 'passed', duration: 3100 },
      { name: 'admin panel access', status: 'failed', duration: 4800, error: 'Element not found: admin-button' }
    ];
    
    for (const test of e2eTests) {
      results.details.push(test);
      
      if (test.status === 'failed') {
        results.errors.push({
          test: test.name,
          error: test.error,
          duration: test.duration
        });
      }
    }
    
    return results;
  }

  /**
   * Execute performance tests
   */
  async executePerformanceTests(testSuite, config) {
    const results = {
      total: 12,
      passed: 10,
      failed: 2,
      skipped: 0,
      errors: [],
      details: []
    };
    
    // Simulate performance test scenarios
    const performanceTests = [
      { name: 'API response time', status: 'passed', duration: 150, metric: '95ms avg' },
      { name: 'Database query performance', status: 'passed', duration: 200, metric: '45ms avg' },
      { name: 'Load test (100 users)', status: 'failed', duration: 15000, error: 'Response time exceeded 1000ms' },
      { name: 'Memory usage test', status: 'passed', duration: 5000, metric: '128MB peak' }
    ];
    
    for (const test of performanceTests) {
      results.details.push(test);
      
      if (test.status === 'failed') {
        results.errors.push({
          test: test.name,
          error: test.error,
          duration: test.duration
        });
      }
    }
    
    return results;
  }

  /**
   * Execute security tests
   */
  async executeSecurityTests(testSuite, config) {
    const results = {
      total: 10,
      passed: 9,
      failed: 1,
      skipped: 0,
      errors: [],
      details: []
    };
    
    // Simulate security test scenarios
    const securityTests = [
      { name: 'SQL injection protection', status: 'passed', duration: 800 },
      { name: 'XSS prevention', status: 'passed', duration: 650 },
      { name: 'Authentication bypass', status: 'passed', duration: 1200 },
      { name: 'Rate limiting', status: 'failed', duration: 900, error: 'Rate limit not enforced' }
    ];
    
    for (const test of securityTests) {
      results.details.push(test);
      
      if (test.status === 'failed') {
        results.errors.push({
          test: test.name,
          error: test.error,
          duration: test.duration
        });
      }
    }
    
    return results;
  }

  /**
   * Collect test coverage data
   */
  async collectCoverage(testSuite) {
    const coverage = {
      lines: 0.85 + Math.random() * 0.1, // 85-95%
      functions: 0.88 + Math.random() * 0.1, // 88-98%
      branches: 0.82 + Math.random() * 0.1, // 82-92%
      statements: 0.87 + Math.random() * 0.1, // 87-97%
      uncoveredLines: [],
      uncoveredFunctions: []
    };
    
    // Simulate uncovered code detection
    if (coverage.lines < 0.9) {
      coverage.uncoveredLines = [
        { file: 'errorHandler.js', line: 145, reason: 'Error path not tested' },
        { file: 'licenseManager.js', line: 89, reason: 'Edge case not covered' }
      ];
    }
    
    this.coverageData.set(testSuite.name, coverage);
    
    return coverage;
  }

  /**
   * Analyze test performance
   */
  async analyzeTestPerformance(testResults) {
    const performance = {
      averageTime: 0,
      slowestTest: null,
      fastestTest: null,
      totalTime: 0,
      testsPerSecond: 0
    };
    
    if (testResults.details.length > 0) {
      const durations = testResults.details.map(test => test.duration);
      const totalDuration = durations.reduce((sum, duration) => sum + duration, 0);
      
      performance.averageTime = totalDuration / durations.length;
      performance.totalTime = totalDuration;
      performance.testsPerSecond = (testResults.total / totalDuration) * 1000;
      
      performance.slowestTest = testResults.details.reduce((slowest, test) => 
        test.duration > (slowest?.duration || 0) ? test : slowest
      );
      
      performance.fastestTest = testResults.details.reduce((fastest, test) => 
        test.duration < (fastest?.duration || Infinity) ? test : fastest
      );
    }
    
    return performance;
  }

  /**
   * Generate AI-powered tests
   */
  async generateAITests(sourceCode, testType = 'unit') {
    const testGeneration = {
      id: this.generateTestGenerationId(),
      timestamp: Date.now(),
      sourceCode: sourceCode.substring(0, 500), // Sample for analysis
      testType,
      generatedTests: [],
      coverage: 0,
      confidence: 0.8
    };
    
    // AI-powered test generation simulation
    const testPatterns = [
      {
        pattern: 'function validation',
        template: 'should validate input parameters',
        confidence: 0.9
      },
      {
        pattern: 'error handling',
        template: 'should handle errors gracefully',
        confidence: 0.85
      },
      {
        pattern: 'edge cases',
        template: 'should handle edge cases correctly',
        confidence: 0.75
      },
      {
        pattern: 'integration points',
        template: 'should integrate with external services',
        confidence: 0.8
      }
    ];
    
    for (const pattern of testPatterns) {
      if (sourceCode.includes(pattern.pattern.split(' ')[0])) {
        testGeneration.generatedTests.push({
          name: pattern.template,
          type: testType,
          confidence: pattern.confidence,
          code: this.generateTestCode(pattern.template, testType)
        });
      }
    }
    
    testGeneration.coverage = testGeneration.generatedTests.length * 0.2; // Estimate coverage
    
    this.testGeneration.set(testGeneration.id, testGeneration);
    
    console.log(`🤖 Generated ${testGeneration.generatedTests.length} AI tests`);
    this.emit('aiTestsGenerated', testGeneration);
    
    return testGeneration;
  }

  /**
   * Generate test code template
   */
  generateTestCode(testName, testType) {
    const templates = {
      unit: `
describe('${testName}', () => {
  it('${testName}', async () => {
    // Arrange
    const input = {};
    
    // Act
    const result = await functionUnderTest(input);
    
    // Assert
    expect(result).toBeDefined();
  });
});`,
      integration: `
describe('${testName}', () => {
  it('${testName}', async () => {
    // Setup integration test
    const service = new ServiceUnderTest();
    
    // Execute integration
    const result = await service.performOperation();
    
    // Verify integration
    expect(result.success).toBe(true);
  });
});`,
      e2e: `
describe('${testName}', () => {
  it('${testName}', async () => {
    // Navigate to page
    await page.goto('/test-page');
    
    // Perform user actions
    await page.click('#test-button');
    
    // Verify results
    await expect(page.locator('#result')).toBeVisible();
  });
});`
    };
    
    return templates[testType] || templates.unit;
  }

  /**
   * Start test monitoring
   */
  startTestMonitoring() {
    // Run automated tests every 4 hours
    setInterval(() => {
      this.runAutomatedTestSuite();
    }, 4 * 60 * 60 * 1000);
    
    console.log('🧪 Test monitoring started');
  }

  /**
   * Run automated test suite
   */
  async runAutomatedTestSuite() {
    console.log('🤖 Running automated test suite...');
    
    const testSuiteNames = Array.from(this.testSuites.keys());
    const results = [];
    
    for (const suiteName of testSuiteNames) {
      try {
        const result = await this.runTestSuite(suiteName, { automated: true });
        results.push(result);
      } catch (error) {
        console.error(`❌ Automated test failed for ${suiteName}:`, error.message);
      }
    }
    
    this.emit('automatedTestsCompleted', results);
  }

  /**
   * Utility methods
   */
  generateTestSuiteId() {
    return 'TS_' + Date.now() + '_' + randomBytes(4).toString('hex').toUpperCase();
  }
  
  generateTestRunId() {
    return 'TR_' + Date.now() + '_' + randomBytes(4).toString('hex').toUpperCase();
  }
  
  generateTestGenerationId() {
    return 'TG_' + Date.now() + '_' + randomBytes(4).toString('hex').toUpperCase();
  }
  
  /**
   * Get testing statistics
   */
  getTestingStats() {
    const suites = Array.from(this.testSuites.values());
    const totalTests = suites.reduce((sum, suite) => sum + suite.totalTests, 0);
    const passedTests = suites.reduce((sum, suite) => sum + suite.passedTests, 0);
    const failedTests = suites.reduce((sum, suite) => sum + suite.failedTests, 0);
    
    return {
      testSuites: {
        total: this.testSuites.size,
        passed: suites.filter(s => s.status === 'passed').length,
        failed: suites.filter(s => s.status === 'failed').length
      },
      tests: {
        total: totalTests,
        passed: passedTests,
        failed: failedTests,
        successRate: totalTests > 0 ? passedTests / totalTests : 0
      },
      coverage: {
        average: suites.reduce((sum, suite) => sum + (suite.coverage || 0), 0) / suites.length,
        minimum: this.testingConfig.minCoverage
      },
      testRuns: {
        total: this.testResults.size,
        recent: Array.from(this.testResults.values()).slice(-10).length
      },
      aiGeneration: {
        total: this.testGeneration.size,
        enabled: this.testingConfig.aiTestGeneration
      }
    };
  }
}
