Build Optimization

/**
 * Comprehensive Build Optimization Framework
 * 
 * This system provides advanced build optimization through intelligent bundling,
 * asset optimization, and performance-focused build strategies. Think of it as
 * a precision manufacturing system that transforms raw materials (source code)
 * into optimized products (production bundles) with maximum efficiency.
 * 
 * Key Capabilities:
 * - Intelligent code splitting and bundle optimization
 * - Advanced asset processing and optimization
 * - Performance budget enforcement and monitoring
 * - Adaptive build strategies based on usage patterns
 * - Development experience optimization with fast rebuilds
 */

class BuildOptimizationFramework {
  constructor(config = {}) {
    this.config = {
      // Build Strategy Configuration
      buildStrategy: config.buildStrategy || 'production-optimized',
      enableDevelopmentOptimizations: config.enableDevelopmentOptimizations !== false,
      enableProductionOptimizations: config.enableProductionOptimizations !== false,
      
      // Bundle Optimization Settings
      bundleOptimization: {
        enableCodeSplitting: config.enableCodeSplitting !== false,
        enableTreeShaking: config.enableTreeShaking !== false,
        enableDeadCodeElimination: config.enableDeadCodeElimination !== false,
        splitChunks: config.splitChunks || 'adaptive',
        chunkSizeLimit: config.chunkSizeLimit || 250000, // 250KB
      },
      
      // Asset Optimization Settings
      assetOptimization: {
        enableImageOptimization: config.enableImageOptimization !== false,
        enableFontOptimization: config.enableFontOptimization !== false,
        enableSVGOptimization: config.enableSVGOptimization !== false,
        compressionLevel: config.compressionLevel || 'optimal'
      },
      
      // Performance Budget Configuration
      performanceBudget: {
        enabled: config.enablePerformanceBudget !== false,
        maxBundleSize: config.maxBundleSize || 500000, // 500KB
        maxAssetSize: config.maxAssetSize || 250000,   // 250KB
        maxChunkSize: config.maxChunkSize || 250000,   // 250KB
        budgetAlerts: config.budgetAlerts !== false
      },
      
      // Caching and Distribution
      caching: {
        enableContentHashing: config.enableContentHashing !== false,
        enableLongTermCaching: config.enableLongTermCaching !== false,
        cacheStrategy: config.cacheStrategy || 'aggressive',
        hashAlgorithm: config.hashAlgorithm || 'sha256'
      },
      
      // Development Experience
      development: {
        enableHotReload: config.enableHotReload !== false,
        enableFastRefresh: config.enableFastRefresh !== false,
        sourceMaps: config.sourceMaps || 'eval-source-map',
        buildCache: config.buildCache !== false
      },
      
      // Analysis and Monitoring
      analysis: {
        enableBundleAnalysis: config.enableBundleAnalysis !== false,
        enablePerformanceTracking: config.enablePerformanceTracking !== false,
        reportingEndpoint: config.reportingEndpoint || '/api/build-metrics',
        enableSizeTracking: config.enableSizeTracking !== false
      },
      
      ...config
    };

    // Initialize optimization components
    this.bundleOptimizer = new BundleOptimizationEngine(this.config);
    this.assetProcessor = new AssetOptimizationProcessor(this.config);
    this.performanceMonitor = new BuildPerformanceMonitor(this.config);
    this.cacheManager = new BuildCacheManager(this.config);
    this.analysisEngine = new BuildAnalysisEngine(this.config);
    
    // Build pipeline components
    this.webpackOptimizer = new WebpackOptimizationManager(this.config);
    this.viteOptimizer = new ViteOptimizationManager(this.config);
    this.rollupOptimizer = new RollupOptimizationManager(this.config);
    
    // Performance and monitoring
    this.buildMetrics = new Map();
    this.performanceBaselines = new Map();
    this.optimizationHistory = [];
    
    this.initialize();
  }

  initialize() {
    // Set up performance monitoring
    this.setupPerformanceMonitoring();
    
    // Initialize build cache
    this.initializeBuildCache();
    
    // Configure optimization strategies
    this.setupOptimizationStrategies();
    
    // Set up bundle analysis
    this.initializeBundleAnalysis();
  }

  /**
   * Intelligent Code Splitting and Bundle Optimization
   * 
   * Modern applications require sophisticated code splitting strategies that
   * balance initial load performance with caching efficiency. This system
   * analyzes application structure and usage patterns to determine optimal
   * splitting points and bundle configurations.
   * 
   * Code Splitting Strategies:
   * - Route-based splitting for page-level optimization
   * - Component-based splitting for granular loading
   * - Library-based splitting for cache stability
   * - Dynamic splitting based on usage analytics
   */
  async optimizeCodeSplitting(entryPoints, dependencyGraph) {
    const splittingStrategy = await this.determineSplittingStrategy(entryPoints, dependencyGraph);
    
    const optimization = {
      strategy: splittingStrategy.type,
      chunks: [],
      cacheGroups: {},
      performance: {},
      recommendations: []
    };

    // Analyze dependency relationships
    const dependencyAnalysis = await this.analyzeDependencyRelationships(dependencyGraph);
    
    // Create optimized chunk configuration
    optimization.chunks = await this.createOptimizedChunks(dependencyAnalysis, splittingStrategy);
    
    // Configure cache groups for vendor libraries
    optimization.cacheGroups = this.configureCacheGroups(dependencyAnalysis);
    
    // Generate performance predictions
    optimization.performance = await this.predictSplittingPerformance(optimization);
    
    return optimization;
  }

  async analyzeDependencyRelationships(dependencyGraph) {
    const analysis = {
      entryPoints: new Map(),
      sharedDependencies: new Map(),
      vendorLibraries: new Map(),
      dynamicImports: new Map(),
      circularDependencies: [],
      unusedDependencies: []
    };

    // Analyze each entry point and its dependencies
    for (const [entryName, dependencies] of Object.entries(dependencyGraph)) {
      const entryAnalysis = {
        name: entryName,
        dependencies: dependencies,
        size: await this.calculateDependencySize(dependencies),
        frequency: await this.getDependencyUsageFrequency(dependencies),
        criticalPath: this.identifyCriticalPath(dependencies)
      };
      
      analysis.entryPoints.set(entryName, entryAnalysis);
    }

    // Identify shared dependencies across entry points
    const allDependencies = new Map();
    
    for (const entryAnalysis of analysis.entryPoints.values()) {
      entryAnalysis.dependencies.forEach(dep => {
        if (!allDependencies.has(dep.name)) {
          allDependencies.set(dep.name, {
            dependency: dep,
            usedBy: new Set(),
            totalSize: dep.size
          });
        }
        allDependencies.get(dep.name).usedBy.add(entryAnalysis.name);
      });
    }

    // Categorize dependencies by usage patterns
    for (const [depName, depInfo] of allDependencies.entries()) {
      if (depInfo.usedBy.size > 1) {
        analysis.sharedDependencies.set(depName, depInfo);
      }
      
      if (this.isVendorLibrary(depName)) {
        analysis.vendorLibraries.set(depName, depInfo);
      }
    }

    return analysis;
  }

  async createOptimizedChunks(dependencyAnalysis, strategy) {
    const chunks = [];

    switch (strategy.type) {
      case 'route-based':
        chunks.push(...await this.createRouteBasedChunks(dependencyAnalysis));
        break;
      
      case 'feature-based':
        chunks.push(...await this.createFeatureBasedChunks(dependencyAnalysis));
        break;
      
      case 'hybrid':
        chunks.push(...await this.createHybridChunks(dependencyAnalysis));
        break;
      
      default:
        chunks.push(...await this.createAdaptiveChunks(dependencyAnalysis));
    }

    // Optimize chunk sizes and dependencies
    return this.optimizeChunkConfiguration(chunks);
  }

  async createRouteBasedChunks(analysis) {
    const routeChunks = [];
    
    // Create vendor chunk for shared libraries
    const vendorChunk = {
      name: 'vendor',
      type: 'vendor',
      dependencies: Array.from(analysis.vendorLibraries.keys()),
      cacheStrategy: 'long-term',
      priority: 10,
      estimatedSize: this.calculateChunkSize(analysis.vendorLibraries)
    };
    
    routeChunks.push(vendorChunk);

    // Create common chunk for shared application code
    const commonDependencies = Array.from(analysis.sharedDependencies.entries())
      .filter(([name, info]) => !this.isVendorLibrary(name) && info.usedBy.size >= 2);
    
    if (commonDependencies.length > 0) {
      const commonChunk = {
        name: 'common',
        type: 'shared',
        dependencies: commonDependencies.map(([name]) => name),
        cacheStrategy: 'medium-term',
        priority: 5,
        estimatedSize: this.calculateChunkSize(new Map(commonDependencies))
      };
      
      routeChunks.push(commonChunk);
    }

    // Create route-specific chunks
    for (const [entryName, entryAnalysis] of analysis.entryPoints.entries()) {
      const routeSpecificDependencies = entryAnalysis.dependencies.filter(dep => 
        !analysis.vendorLibraries.has(dep.name) && 
        !analysis.sharedDependencies.has(dep.name)
      );
      
      if (routeSpecificDependencies.length > 0) {
        const routeChunk = {
          name: `route-${entryName}`,
          type: 'route',
          dependencies: routeSpecificDependencies.map(dep => dep.name),
          cacheStrategy: 'short-term',
          priority: 1,
          estimatedSize: this.calculateDependencySize(routeSpecificDependencies),
          lazyLoad: !entryAnalysis.criticalPath
        };
        
        routeChunks.push(routeChunk);
      }
    }

    return routeChunks;
  }

  /**
   * Advanced Tree Shaking and Dead Code Elimination
   * 
   * Tree shaking removes unused code from bundles, but requires sophisticated
   * analysis to identify truly unused code while avoiding breaking
   * side-effect-dependent libraries and dynamic code patterns.
   * 
   * Tree Shaking Strategies:
   * - ES6 module analysis for static elimination
   * - Side-effect tracking for safe removal
   * - Cross-module dependency analysis
   * - Runtime usage pattern analysis
   */
  async optimizeTreeShaking(modules, usageAnalytics) {
    const treeShakingConfig = {
      enabled: true,
      optimization: {},
      sideEffects: new Set(),
      preserveModules: new Set(),
      eliminationReport: {}
    };

    // Analyze module side effects
    const sideEffectAnalysis = await this.analyzeSideEffects(modules);
    treeShakingConfig.sideEffects = sideEffectAnalysis.sideEffectModules;

    // Identify unused exports
    const unusedExports = await this.identifyUnusedExports(modules, usageAnalytics);
    
    // Configure webpack tree shaking optimization
    treeShakingConfig.optimization = {
      usedExports: true,
      sideEffects: Array.from(treeShakingConfig.sideEffects),
      providedExports: true,
      innerGraph: true, // Enable inner graph analysis for more precise tree shaking
      mangleExports: true,
      
      // Advanced tree shaking configuration
      concatenateModules: true, // Enable module concatenation
      flagIncludedChunks: true,
      mergeDuplicateChunks: true,
      removeAvailableModules: true,
      removeEmptyChunks: true
    };

    // Generate elimination report
    treeShakingConfig.eliminationReport = {
      totalModules: modules.length,
      unusedExports: unusedExports.length,
      eliminatedSize: await this.calculateEliminatedSize(unusedExports),
      preservedModules: treeShakingConfig.preserveModules.size,
      sideEffectModules: treeShakingConfig.sideEffects.size
    };

    return treeShakingConfig;
  }

  async analyzeSideEffects(modules) {
    const analysis = {
      sideEffectModules: new Set(),
      safeDependencies: new Set(),
      suspiciousPatterns: []
    };

    for (const module of modules) {
      // Check package.json sideEffects declaration
      if (module.packageInfo && module.packageInfo.sideEffects === false) {
        analysis.safeDependencies.add(module.name);
        continue;
      }

      // Analyze module code for side effect patterns
      const codeAnalysis = await this.analyzeModuleCode(module);
      
      if (this.hasSideEffects(codeAnalysis)) {
        analysis.sideEffectModules.add(module.name);
        
        // Document why this module has side effects
        analysis.suspiciousPatterns.push({
          module: module.name,
          patterns: codeAnalysis.sideEffectPatterns,
          confidence: codeAnalysis.confidence
        });
      }
    }

    return analysis;
  }

  hasSideEffects(codeAnalysis) {
    const sideEffectIndicators = [
      'globalVariableModification',
      'prototypeModification',
      'windowObjectAccess',
      'documentModification',
      'cssImports',
      'polyfillRegistration',
      'eventListenerRegistration'
    ];

    return sideEffectIndicators.some(indicator => 
      codeAnalysis.patterns.includes(indicator)
    );
  }

  /**
   * Asset Optimization and Processing Pipeline
   * 
   * Modern web applications include diverse asset types that require
   * specialized optimization strategies. This system provides intelligent
   * asset processing that optimizes for performance while maintaining quality.
   * 
   * Asset Optimization Features:
   * - Image format selection and compression
   * - Font subsetting and optimization
   * - SVG optimization and sprite generation
   * - CSS and JavaScript minification
   */
  async optimizeAssets(assets) {
    const optimizationResults = {
      images: await this.optimizeImages(assets.images || []),
      fonts: await this.optimizeFonts(assets.fonts || []),
      svgs: await this.optimizeSVGs(assets.svgs || []),
      styles: await this.optimizeStyles(assets.styles || []),
      scripts: await this.optimizeScripts(assets.scripts || []),
      totalSavings: 0
    };

    // Calculate total optimization savings
    optimizationResults.totalSavings = Object.values(optimizationResults)
      .filter(result => typeof result === 'object' && result.savings)
      .reduce((total, result) => total + result.savings, 0);

    return optimizationResults;
  }

  async optimizeImages(images) {
    const optimization = {
      processed: [],
      savings: 0,
      formats: new Map()
    };

    for (const image of images) {
      const imageOptimization = await this.processImage(image);
      optimization.processed.push(imageOptimization);
      optimization.savings += imageOptimization.sizeSaving;
      
      // Track format usage
      const format = imageOptimization.outputFormat;
      optimization.formats.set(format, (optimization.formats.get(format) || 0) + 1);
    }

    return optimization;
  }

  async processImage(image) {
    const optimization = {
      originalPath: image.path,
      originalSize: image.size,
      originalFormat: image.format,
      optimized: {},
      recommendations: []
    };

    // Determine optimal format based on image characteristics
    const optimalFormat = this.determineOptimalImageFormat(image);
    
    // Generate optimized versions
    if (optimalFormat.supportsWebP) {
      optimization.optimized.webp = await this.generateWebPVersion(image);
    }
    
    if (optimalFormat.supportsAVIF) {
      optimization.optimized.avif = await this.generateAVIFVersion(image);
    }

    // Generate responsive variants if needed
    if (image.responsive) {
      optimization.optimized.responsive = await this.generateResponsiveVariants(image);
    }

    // Compress original format
    optimization.optimized.compressed = await this.compressImage(image, {
      quality: this.calculateOptimalQuality(image),
      progressive: image.format === 'jpeg'
    });

    // Calculate size savings
    const bestOptimized = this.selectBestOptimization(optimization.optimized);
    optimization.sizeSaving = optimization.originalSize - bestOptimized.size;
    optimization.compressionRatio = bestOptimized.size / optimization.originalSize;

    // Generate recommendations
    if (optimization.compressionRatio < 0.5) {
      optimization.recommendations.push('Consider lazy loading for this large image');
    }
    
    if (image.aboveTheFold && optimization.sizeSaving > 50000) {
      optimization.recommendations.push('Consider preloading this optimized version');
    }

    return optimization;
  }

  determineOptimalImageFormat(image) {
    const recommendation = {
      primary: image.format,
      supportsWebP: true,
      supportsAVIF: false, // Conservative default
      reasoning: []
    };

    // Analyze image characteristics
    if (image.hasTransparency) {
      if (image.format === 'png') {
        recommendation.supportsWebP = true;
        recommendation.supportsAVIF = true;
        recommendation.reasoning.push('PNG with transparency benefits from WebP/AVIF');
      }
    } else if (image.isPhotographic) {
      recommendation.primary = 'jpeg';
      recommendation.supportsWebP = true;
      recommendation.supportsAVIF = true;
      recommendation.reasoning.push('Photographic content optimizes well with JPEG/WebP/AVIF');
    } else if (image.isGraphic || image.hasLimitedColors) {
      recommendation.primary = 'png';
      recommendation.supportsWebP = true;
      recommendation.reasoning.push('Graphic content works well with PNG/WebP');
    }

    // Consider file size thresholds
    if (image.size > 100000) { // 100KB
      recommendation.supportsAVIF = true;
      recommendation.reasoning.push('Large images benefit significantly from AVIF compression');
    }

    return recommendation;
  }

  /**
   * Performance Budget Enforcement and Monitoring
   * 
   * Performance budgets prevent performance regressions by setting limits
   * on bundle sizes, asset sizes, and other performance metrics. This system
   * provides intelligent budget management with actionable recommendations.
   * 
   * Budget Categories:
   * - Bundle size budgets (total and individual chunks)
   * - Asset size budgets (images, fonts, etc.)
   * - Performance metric budgets (LCP, TTI, etc.)
   * - Network request budgets (count and payload)
   */
  async enforcePerformanceBudget(buildOutput) {
    const budgetAnalysis = {
      overall: { passed: true, violations: [] },
      categories: {
        bundles: await this.checkBundleBudgets(buildOutput.bundles),
        assets: await this.checkAssetBudgets(buildOutput.assets),
        network: await this.checkNetworkBudgets(buildOutput.requests)
      },
      recommendations: [],
      trends: await this.analyzeBudgetTrends()
    };

    // Aggregate results
    const allViolations = [
      ...budgetAnalysis.categories.bundles.violations,
      ...budgetAnalysis.categories.assets.violations,
      ...budgetAnalysis.categories.network.violations
    ];

    budgetAnalysis.overall.passed = allViolations.length === 0;
    budgetAnalysis.overall.violations = allViolations;

    // Generate actionable recommendations
    budgetAnalysis.recommendations = this.generateBudgetRecommendations(budgetAnalysis);

    // Trigger alerts if budget is exceeded
    if (!budgetAnalysis.overall.passed && this.config.performanceBudget.budgetAlerts) {
      await this.triggerBudgetAlerts(budgetAnalysis);
    }

    return budgetAnalysis;
  }

  async checkBundleBudgets(bundles) {
    const budgetCheck = {
      passed: true,
      violations: [],
      details: []
    };

    for (const bundle of bundles) {
      const bundleAnalysis = {
        name: bundle.name,
        size: bundle.size,
        limit: this.getBundleSizeLimit(bundle),
        passed: true,
        overage: 0
      };

      if (bundle.size > bundleAnalysis.limit) {
        bundleAnalysis.passed = false;
        bundleAnalysis.overage = bundle.size - bundleAnalysis.limit;
        budgetCheck.passed = false;
        
        budgetCheck.violations.push({
          type: 'bundle-size',
          bundle: bundle.name,
          size: bundle.size,
          limit: bundleAnalysis.limit,
          overage: bundleAnalysis.overage,
          severity: this.calculateViolationSeverity(bundleAnalysis.overage, bundleAnalysis.limit)
        });
      }

      budgetCheck.details.push(bundleAnalysis);
    }

    return budgetCheck;
  }

  getBundleSizeLimit(bundle) {
    // Different limits for different bundle types
    const limits = {
      'vendor': this.config.performanceBudget.maxVendorSize || 500000,   // 500KB
      'common': this.config.performanceBudget.maxCommonSize || 200000,   // 200KB  
      'route': this.config.performanceBudget.maxRouteSize || 150000,     // 150KB
      'default': this.config.performanceBudget.maxBundleSize || 250000   // 250KB
    };

    return limits[bundle.type] || limits.default;
  }

  generateBudgetRecommendations(budgetAnalysis) {
    const recommendations = [];

    // Bundle size recommendations
    budgetAnalysis.categories.bundles.violations.forEach(violation => {
      if (violation.type === 'bundle-size') {
        recommendations.push({
          category: 'bundle-optimization',
          priority: violation.severity,
          message: `Bundle "${violation.bundle}" exceeds size limit by ${violation.overage} bytes`,
          suggestions: [
            'Enable tree shaking for unused code elimination',
            'Consider code splitting for lazy loading',
            'Analyze bundle contents for unnecessary dependencies',
            'Use dynamic imports for non-critical features'
          ]
        });
      }
    });

    // Asset optimization recommendations
    budgetAnalysis.categories.assets.violations.forEach(violation => {
      if (violation.type === 'asset-size') {
        recommendations.push({
          category: 'asset-optimization',
          priority: violation.severity,
          message: `Asset "${violation.asset}" exceeds size limit`,
          suggestions: [
            'Enable image optimization and modern formats',
            'Implement responsive images with appropriate sizes',
            'Consider lazy loading for below-the-fold assets',
            'Use font subsetting for custom fonts'
          ]
        });
      }
    });

    return recommendations;
  }

  /**
   * Build Cache Management and Optimization
   * 
   * Intelligent caching dramatically improves build performance by avoiding
   * unnecessary reprocessing of unchanged assets and dependencies.
   * This system provides multi-level caching with intelligent invalidation.
   * 
   * Caching Levels:
   * - Module-level caching for individual file processing
   * - Dependency-level caching for package resolution
   * - Asset-level caching for optimization results
   * - Build-level caching for complete build artifacts
   */
  async optimizeBuildCache() {
    const cacheOptimization = {
      enabled: this.config.development.buildCache,
      strategy: 'intelligent-invalidation',
      levels: {
        filesystem: await this.optimizeFilesystemCache(),
        memory: await this.optimizeMemoryCache(),
        distributed: await this.optimizeDistributedCache()
      },
      performance: {},
      statistics: {}
    };

    // Analyze cache effectiveness
    cacheOptimization.performance = await this.analyzeCachePerformance();
    
    // Generate cache statistics
    cacheOptimization.statistics = await this.generateCacheStatistics();

    return cacheOptimization;
  }

  async optimizeFilesystemCache() {
    const filesystemCache = {
      enabled: true,
      location: '.cache/build-optimization',
      strategy: 'content-hash-based',
      maxSize: '2GB',
      cleanup: {
        enabled: true,
        maxAge: 7 * 24 * 60 * 60 * 1000, // 7 days
        unusedThreshold: 30 * 24 * 60 * 60 * 1000 // 30 days
      }
    };

    // Configure cache key generation
    filesystemCache.keyGeneration = {
      includeNodeVersion: true,
      includeDependencyVersions: true,
      includeConfigurationHash: true,
      includeEnvironmentVariables: ['NODE_ENV', 'BUILD_TARGET']
    };

    return filesystemCache;
  }

  // Build performance monitoring and analysis
  async monitorBuildPerformance(buildStartTime, buildResult) {
    const buildEndTime = Date.now();
    const buildDuration = buildEndTime - buildStartTime;

    const performanceMetrics = {
      timestamp: buildEndTime,
      duration: buildDuration,
      buildSize: buildResult.totalSize,
      assetCount: buildResult.assetCount,
      chunkCount: buildResult.chunkCount,
      cacheHitRate: await this.calculateCacheHitRate(),
      memoryUsage: process.memoryUsage(),
      phases: buildResult.phaseTimings || {}
    };

    // Store metrics for trend analysis
    this.buildMetrics.set(buildEndTime, performanceMetrics);
    
    // Analyze performance trends
    const trendAnalysis = await this.analyzeBuildTrends();
    
    // Generate optimization recommendations
    const optimizationRecommendations = this.generateBuildOptimizationRecommendations(
      performanceMetrics, 
      trendAnalysis
    );

    return {
      metrics: performanceMetrics,
      trends: trendAnalysis,
      recommendations: optimizationRecommendations
    };
  }

  generateBuildOptimizationRecommendations(metrics, trends) {
    const recommendations = [];

    // Build time recommendations
    if (metrics.duration > 60000) { // More than 1 minute
      recommendations.push({
        category: 'build-performance',
        priority: 'high',
        message: 'Build time exceeds 1 minute',
        suggestions: [
          'Enable build caching to avoid reprocessing unchanged files',
          'Consider using faster build tools like esbuild for development',
          'Implement incremental compilation strategies',
          'Parallelize build processes where possible'
        ]
      });
    }

    // Bundle size recommendations
    if (metrics.buildSize > 2000000) { // More than 2MB
      recommendations.push({
        category: 'bundle-size',
        priority: 'medium',
        message: 'Total build size is large',
        suggestions: [
          'Implement aggressive code splitting strategies',
          'Enable tree shaking and dead code elimination',
          'Analyze and remove unused dependencies',
          'Consider lazy loading for non-critical features'
        ]
      });
    }

    // Cache efficiency recommendations
    if (metrics.cacheHitRate < 0.8) { // Less than 80% cache hit rate
      recommendations.push({
        category: 'cache-optimization',
        priority: 'medium',
        message: 'Build cache efficiency could be improved',
        suggestions: [
          'Optimize cache key generation for better hit rates',
          'Increase cache size limits if storage allows',
          'Review cache invalidation strategies',
          'Enable distributed caching for team builds'
        ]
      });
    }

    return recommendations;
  }
}

// Specialized optimization engines
class BundleOptimizationEngine {
  constructor(config) {
    this.config = config;
  }

  async createWebpackOptimization() {
    return {
      // Production optimizations
      minimizer: [
        new TerserPlugin({
          parallel: true,
          terserOptions: {
            compress: {
              drop_console: true,
              drop_debugger: true,
              pure_funcs: ['console.log']
            },
            mangle: {
              safari10: true
            }
          }
        }),
        new CssMinimizerPlugin()
      ],
      
      // Chunk splitting configuration
      splitChunks: {
        chunks: 'all',
        minSize: 20000,
        maxSize: 250000,
        cacheGroups: {
          vendor: {
            test: /[\\/]node_modules[\\/]/,
            name: 'vendors',
            chunks: 'all',
            priority: 10
          },
          common: {
            minChunks: 2,
            chunks: 'all',
            priority: 5,
            reuseExistingChunk: true
          }
        }
      },
      
      // Tree shaking and module concatenation
      usedExports: true,
      sideEffects: false,
      concatenateModules: true
    };
  }
}

// Usage Examples and Integration
const buildOptimizer = new BuildOptimizationFramework({
  buildStrategy: 'production-optimized',
  enableCodeSplitting: true,
  enableTreeShaking: true,
  enablePerformanceBudget: true,
  maxBundleSize: 250000,
  enableBuildCache: true
});

// Example: Complete build optimization workflow
async function optimizeBuild(buildConfig) {
  const buildStartTime = Date.now();
  
  // Optimize code splitting
  const codeSplittingConfig = await buildOptimizer.optimizeCodeSplitting(
    buildConfig.entryPoints, 
    buildConfig.dependencyGraph
  );
  
  // Configure asset optimization
  const assetOptimization = await buildOptimizer.optimizeAssets(buildConfig.assets);
  
  // Set up performance budget enforcement
  const budgetConfig = buildOptimizer.setupPerformanceBudget({
    maxBundleSize: 300000,
    maxAssetSize: 200000
  });
  
  // Execute optimized build
  const buildResult = await executeOptimizedBuild({
    codeSplitting: codeSplittingConfig,
    assetOptimization: assetOptimization,
    budget: budgetConfig
  });
  
  // Monitor and analyze build performance
  const performanceAnalysis = await buildOptimizer.monitorBuildPerformance(
    buildStartTime, 
    buildResult
  );
  
  console.log('Build Optimization Complete:', {
    duration: performanceAnalysis.metrics.duration + 'ms',
    totalSize: buildResult.totalSize + ' bytes',
    chunkCount: buildResult.chunkCount,
    cacheHitRate: (performanceAnalysis.metrics.cacheHitRate * 100).toFixed(1) + '%'
  });
  
  return buildResult;
}

export { BuildOptimizationFramework };

async analyzeDependencyRelationships(dependencyGraph) {
  const analysis = {
    entryPoints: new Map(),
    sharedDependencies: new Map(),
    vendorLibraries: new Map(),
    circularDependencies: []
  };

  // Analyze each entry point and its dependencies
  for (const [entryName, dependencies] of Object.entries(dependencyGraph)) {
    const entryAnalysis = {
      dependencies: dependencies,
      size: await this.calculateDependencySize(dependencies),
      frequency: await this.getDependencyUsageFrequency(dependencies),
      criticalPath: this.identifyCriticalPath(dependencies)
    };
    
    analysis.entryPoints.set(entryName, entryAnalysis);
  }

  // Identify shared dependencies across entry points
  for (const entryAnalysis of analysis.entryPoints.values()) {
    entryAnalysis.dependencies.forEach(dep => {
      if (!allDependencies.has(dep.name)) {
        allDependencies.set(dep.name, { usedBy: new Set() });
      }
      allDependencies.get(dep.name).usedBy.add(entryAnalysis.name);
    });
  }

  return analysis;
}

async analyzeSideEffects(modules) {
  const analysis = {
    sideEffectModules: new Set(),
    safeDependencies: new Set(),
    suspiciousPatterns: []
  };

  for (const module of modules) {
    // Check package.json sideEffects declaration
    if (module.packageInfo?.sideEffects === false) {
      analysis.safeDependencies.add(module.name);
      continue;
    }

    // Analyze module code for side effect patterns
    const codeAnalysis = await this.analyzeModuleCode(module);
    
    if (this.hasSideEffects(codeAnalysis)) {
      analysis.sideEffectModules.add(module.name);
    }
  }

  return analysis;
}

hasSideEffects(codeAnalysis) {
  const sideEffectIndicators = [
    'globalVariableModification',      // Modifies global state
    'prototypeModification',           // Extends built-in prototypes
    'windowObjectAccess',              // Accesses browser globals
    'cssImports',                      // Imports CSS files
    'polyfillRegistration'             // Registers polyfills
  ];

  return sideEffectIndicators.some(indicator => 
    codeAnalysis.patterns.includes(indicator)
  );
}

determineOptimalImageFormat(image) {
  const recommendation = {
    primary: image.format,
    supportsWebP: true,
    supportsAVIF: false,
    reasoning: []
  };

  // Analyze image characteristics for format selection
  if (image.hasTransparency && image.format === 'png') {
    recommendation.supportsWebP = true;
    recommendation.supportsAVIF = true;
    recommendation.reasoning.push('PNG with transparency benefits from WebP/AVIF');
  } else if (image.isPhotographic) {
    recommendation.primary = 'jpeg';
    recommendation.supportsWebP = true;
    recommendation.supportsAVIF = true;
    recommendation.reasoning.push('Photographic content optimizes well with JPEG/WebP/AVIF');
  }

  // Consider file size for AVIF adoption
  if (image.size > 100000) { // 100KB threshold
    recommendation.supportsAVIF = true;
    recommendation.reasoning.push('Large images benefit significantly from AVIF compression');
  }

  return recommendation;
}

async checkBundleBudgets(bundles) {
  const budgetCheck = { passed: true, violations: [] };

  for (const bundle of bundles) {
    const limit = this.getBundleSizeLimit(bundle);
    
    if (bundle.size > limit) {
      budgetCheck.passed = false;
      
      budgetCheck.violations.push({
        type: 'bundle-size',
        bundle: bundle.name,
        size: bundle.size,
        limit: limit,
        overage: bundle.size - limit,
        severity: this.calculateViolationSeverity(bundle.size - limit, limit)
      });
    }
  }

  return budgetCheck;
}

generateBudgetRecommendations(budgetAnalysis) {
  const recommendations = [];
  
  budgetAnalysis.categories.bundles.violations.forEach(violation => {
    recommendations.push({
      category: 'bundle-optimization',
      priority: violation.severity,
      message: `Bundle "${violation.bundle}" exceeds size limit by ${violation.overage} bytes`,
      suggestions: [
        'Enable tree shaking for unused code elimination',
        'Consider code splitting for lazy loading',
        'Analyze bundle contents for unnecessary dependencies'
      ]
    });
  });

  return recommendations;
}

async optimizeFilesystemCache() {
  const filesystemCache = {
    enabled: true,
    location: '.cache/build-optimization',
    strategy: 'content-hash-based',
    maxSize: '2GB',
    cleanup: {
      maxAge: 7 * 24 * 60 * 60 * 1000,        // 7 days
      unusedThreshold: 30 * 24 * 60 * 60 * 1000 // 30 days for unused entries
    }
  };

  // Configure intelligent cache key generation
  filesystemCache.keyGeneration = {
    includeNodeVersion: true,              // Node.js version affects compilation
    includeDependencyVersions: true,       // Package versions affect output
    includeConfigurationHash: true,        // Build config changes invalidate cache
    includeEnvironmentVariables: ['NODE_ENV', 'BUILD_TARGET']
  };

  return filesystemCache;
}

generateBuildOptimizationRecommendations(metrics, trends) {
  const recommendations = [];

  // Build time analysis
  if (metrics.duration > 60000) { // More than 1 minute
    recommendations.push({
      category: 'build-performance',
      priority: 'high',
      suggestions: [
        'Enable build caching to avoid reprocessing unchanged files',
        'Consider using faster build tools like esbuild for development',
        'Implement incremental compilation strategies'
      ]
    });
  }

  // Cache efficiency analysis
  if (metrics.cacheHitRate < 0.8) { // Less than 80% cache hit rate
    recommendations.push({
      category: 'cache-optimization',
      suggestions: [
        'Optimize cache key generation for better hit rates',
        'Review cache invalidation strategies',
        'Enable distributed caching for team builds'
      ]
    });
  }

  return recommendations;
}