rezilient.js/src/core/AetherErrorBoundary.js

Rezilient.js - Revolutionary offline-first framework with AI-awareness, principle-driven development, carbon-conscious computing, and self-healing capabilities

/**
 * Aether.js Revolutionary Error Boundary System
 * 
 * Features:
 * - Predictive error prevention
 * - Self-healing capabilities
 * - Context-aware error recovery
 * - User experience preservation
 * - Learning from failures
 * - Graceful degradation strategies
 */

import { withPrinciples } from './AetherPrinciples.js';

/**
 * Error Severity Levels
 */
export const ERROR_SEVERITY = {
  TRACE: 0,     // Debug information
  INFO: 1,      // Informational
  WARNING: 2,   // Warning conditions
  ERROR: 3,     // Error conditions
  CRITICAL: 4,  // Critical conditions
  FATAL: 5      // System unusable
};

/**
 * Recovery Strategies
 */
export const RECOVERY_STRATEGIES = {
  RETRY: 'retry',
  FALLBACK: 'fallback',
  GRACEFUL_DEGRADATION: 'graceful_degradation',
  USER_INTERVENTION: 'user_intervention',
  SYSTEM_RESTART: 'system_restart',
  SAFE_MODE: 'safe_mode'
};

/**
 * Revolutionary Error Boundary
 */
export class AetherErrorBoundary {
  constructor(options = {}) {
    this.options = {
      maxRetries: 3,
      retryDelay: 1000,
      enablePrediction: true,
      enableSelfHealing: true,
      enableLearning: true,
      fallbackComponent: null,
      onError: null,
      ...options
    };
    
    // Error tracking
    this.errorHistory = [];
    this.errorPatterns = new Map();
    this.recoveryAttempts = new Map();
    this.healingStrategies = new Map();
    
    // Predictive system
    this.errorPredictors = new Map();
    this.riskFactors = new Map();
    
    // Performance monitoring
    this.performanceMetrics = {
      errorRate: 0,
      recoveryRate: 0,
      meanTimeToRecovery: 0,
      userImpact: 0
    };
    
    this.initializeErrorBoundary();
  }

  /**
   * Initialize error boundary system
   */
  initializeErrorBoundary() {
    this.setupGlobalErrorHandling();
    this.setupPredictiveSystem();
    this.setupSelfHealingSystem();
    this.setupPerformanceMonitoring();
  }

  /**
   * Global error handling setup
   */
  setupGlobalErrorHandling() {
    // Catch unhandled promise rejections
    if (typeof window !== 'undefined') {
      window.addEventListener('unhandledrejection', (event) => {
        this.handleError(event.reason, {
          type: 'unhandled_promise_rejection',
          source: 'global'
        });
      });
      
      // Catch global errors
      window.addEventListener('error', (event) => {
        this.handleError(event.error, {
          type: 'global_error',
          source: event.filename,
          line: event.lineno,
          column: event.colno
        });
      });
    }
  }

  /**
   * Predictive error system
   */
  setupPredictiveSystem() {
    if (!this.options.enablePrediction) return;
    
    this.errorPredictor = {
      analyzeRiskFactors: (context) => {
        const riskScore = this.calculateRiskScore(context);
        
        if (riskScore > 0.7) {
          this.preventiveAction(context, riskScore);
        }
        
        return riskScore;
      },
      
      predictErrorProbability: (operation, context) => {
        const historicalData = this.getHistoricalErrorData(operation);
        const contextualRisk = this.assessContextualRisk(context);
        
        return this.combineRiskFactors(historicalData, contextualRisk);
      },
      
      recommendPreventiveMeasures: (riskScore, context) => {
        const measures = [];
        
        if (riskScore > 0.8) {
          measures.push({
            type: 'circuit_breaker',
            description: 'Temporarily disable risky operations',
            priority: 'high'
          });
        }
        
        if (riskScore > 0.6) {
          measures.push({
            type: 'resource_allocation',
            description: 'Allocate additional resources',
            priority: 'medium'
          });
        }
        
        if (riskScore > 0.4) {
          measures.push({
            type: 'monitoring_increase',
            description: 'Increase monitoring frequency',
            priority: 'low'
          });
        }
        
        return measures;
      }
    };
  }

  /**
   * Self-healing system
   */
  setupSelfHealingSystem() {
    if (!this.options.enableSelfHealing) return;
    
    this.selfHealer = {
      diagnose: (error, context) => {
        const diagnosis = {
          errorType: this.classifyError(error),
          severity: this.assessSeverity(error, context),
          rootCause: this.identifyRootCause(error, context),
          affectedSystems: this.identifyAffectedSystems(error, context),
          healingStrategy: null
        };
        
        diagnosis.healingStrategy = this.selectHealingStrategy(diagnosis);
        return diagnosis;
      },
      
      heal: async (diagnosis) => {
        const strategy = diagnosis.healingStrategy;
        
        try {
          const result = await this.executeHealingStrategy(strategy, diagnosis);
          
          if (result.success) {
            this.recordSuccessfulHealing(diagnosis, strategy, result);
          } else {
            this.escalateHealing(diagnosis, result);
          }
          
          return result;
        } catch (healingError) {
          return {
            success: false,
            error: healingError,
            requiresEscalation: true
          };
        }
      },
      
      learn: (diagnosis, strategy, result) => {
        if (!this.options.enableLearning) return;
        
        const learningData = {
          errorPattern: this.extractErrorPattern(diagnosis),
          strategy: strategy.type,
          success: result.success,
          context: diagnosis.context,
          timestamp: Date.now()
        };
        
        this.updateHealingKnowledge(learningData);
      }
    };
  }

  /**
   * Performance monitoring
   */
  setupPerformanceMonitoring() {
    this.performanceMonitor = {
      trackError: (error, context) => {
        this.performanceMetrics.errorRate = this.calculateErrorRate();
      },
      
      trackRecovery: (recovery) => {
        this.performanceMetrics.recoveryRate = this.calculateRecoveryRate();
        this.performanceMetrics.meanTimeToRecovery = this.calculateMTTR();
      },
      
      trackUserImpact: (impact) => {
        this.performanceMetrics.userImpact = this.calculateUserImpact(impact);
      },
      
      generateReport: () => {
        return {
          ...this.performanceMetrics,
          totalErrors: this.errorHistory.length,
          uniqueErrorTypes: new Set(this.errorHistory.map(e => e.type)).size,
          healingSuccessRate: this.calculateHealingSuccessRate(),
          timestamp: Date.now()
        };
      }
    };
  }

  /**
   * Main error handling method
   */
  async handleError(error, context = {}) {
    const errorId = this.generateErrorId();
    const timestamp = Date.now();
    
    // Record error
    const errorRecord = {
      id: errorId,
      error,
      context,
      timestamp,
      severity: this.assessSeverity(error, context),
      handled: false,
      recovered: false
    };
    
    this.errorHistory.push(errorRecord);
    this.updateErrorPatterns(errorRecord);
    
    // Attempt recovery
    try {
      const recovery = await this.attemptRecovery(errorRecord);
      errorRecord.recovered = recovery.success;
      errorRecord.recoveryStrategy = recovery.strategy;
      
      if (recovery.success) {
        this.performanceMonitor.trackRecovery(recovery);
        return recovery;
      } else {
        return this.handleRecoveryFailure(errorRecord, recovery);
      }
    } catch (recoveryError) {
      return this.handleCriticalFailure(errorRecord, recoveryError);
    }
  }

  /**
   * Attempt error recovery
   */
  async attemptRecovery(errorRecord) {
    const { error, context } = errorRecord;
    
    // Check if we've seen this error before
    const knownPattern = this.findKnownErrorPattern(error);
    
    if (knownPattern && knownPattern.successfulStrategy) {
      return this.executeRecoveryStrategy(knownPattern.successfulStrategy, errorRecord);
    }
    
    // Try predictive healing if enabled
    if (this.options.enableSelfHealing) {
      const diagnosis = this.selfHealer.diagnose(error, context);
      const healingResult = await this.selfHealer.heal(diagnosis);
      
      if (healingResult.success) {
        this.selfHealer.learn(diagnosis, diagnosis.healingStrategy, healingResult);
        return {
          success: true,
          strategy: RECOVERY_STRATEGIES.FALLBACK,
          method: 'self_healing',
          result: healingResult
        };
      }
    }
    
    // Try standard recovery strategies
    const strategies = this.getRecoveryStrategies(errorRecord);
    
    for (const strategy of strategies) {
      try {
        const result = await this.executeRecoveryStrategy(strategy, errorRecord);
        
        if (result.success) {
          this.recordSuccessfulStrategy(errorRecord, strategy);
          return result;
        }
      } catch (strategyError) {
        // Continue to next strategy
        continue;
      }
    }
    
    return {
      success: false,
      strategy: null,
      reason: 'All recovery strategies failed'
    };
  }

  /**
   * Execute recovery strategy
   */
  async executeRecoveryStrategy(strategy, errorRecord) {
    switch (strategy.type) {
      case RECOVERY_STRATEGIES.RETRY:
        return this.executeRetryStrategy(strategy, errorRecord);
      
      case RECOVERY_STRATEGIES.FALLBACK:
        return this.executeFallbackStrategy(strategy, errorRecord);
      
      case RECOVERY_STRATEGIES.GRACEFUL_DEGRADATION:
        return this.executeGracefulDegradation(strategy, errorRecord);
      
      case RECOVERY_STRATEGIES.USER_INTERVENTION:
        return this.requestUserIntervention(strategy, errorRecord);
      
      case RECOVERY_STRATEGIES.SAFE_MODE:
        return this.enterSafeMode(strategy, errorRecord);
      
      default:
        throw new Error(`Unknown recovery strategy: ${strategy.type}`);
    }
  }

  /**
   * Retry strategy
   */
  async executeRetryStrategy(strategy, errorRecord) {
    const maxRetries = strategy.maxRetries || this.options.maxRetries;
    const delay = strategy.delay || this.options.retryDelay;
    
    for (let attempt = 1; attempt <= maxRetries; attempt++) {
      try {
        await this.delay(delay * attempt); // Exponential backoff
        
        // Re-execute the failed operation
        const result = await this.retryOperation(errorRecord);
        
        return {
          success: true,
          strategy: RECOVERY_STRATEGIES.RETRY,
          attempts: attempt,
          result
        };
      } catch (retryError) {
        if (attempt === maxRetries) {
          return {
            success: false,
            strategy: RECOVERY_STRATEGIES.RETRY,
            attempts: attempt,
            error: retryError
          };
        }
      }
    }
  }

  /**
   * Fallback strategy
   */
  async executeFallbackStrategy(strategy, errorRecord) {
    try {
      const fallbackComponent = strategy.fallback || this.options.fallbackComponent;
      
      if (!fallbackComponent) {
        return {
          success: false,
          strategy: RECOVERY_STRATEGIES.FALLBACK,
          reason: 'No fallback component available'
        };
      }
      
      const result = await this.activateFallback(fallbackComponent, errorRecord);
      
      return {
        success: true,
        strategy: RECOVERY_STRATEGIES.FALLBACK,
        fallback: fallbackComponent,
        result
      };
    } catch (fallbackError) {
      return {
        success: false,
        strategy: RECOVERY_STRATEGIES.FALLBACK,
        error: fallbackError
      };
    }
  }

  /**
   * Graceful degradation
   */
  async executeGracefulDegradation(strategy, errorRecord) {
    try {
      const degradedFeatures = this.identifyDegradableFeatures(errorRecord);
      const essentialFeatures = this.identifyEssentialFeatures(errorRecord);
      
      // Disable non-essential features
      await this.disableFeatures(degradedFeatures);
      
      // Ensure essential features remain functional
      await this.ensureEssentialFeatures(essentialFeatures);
      
      return {
        success: true,
        strategy: RECOVERY_STRATEGIES.GRACEFUL_DEGRADATION,
        degradedFeatures,
        essentialFeatures
      };
    } catch (degradationError) {
      return {
        success: false,
        strategy: RECOVERY_STRATEGIES.GRACEFUL_DEGRADATION,
        error: degradationError
      };
    }
  }

  /**
   * Get error boundary status
   */
  getStatus() {
    return {
      errorHistory: this.errorHistory.slice(-10), // Last 10 errors
      errorPatterns: Array.from(this.errorPatterns.entries()),
      performanceMetrics: this.performanceMonitor.generateReport(),
      healingStrategies: Array.from(this.healingStrategies.entries()),
      options: this.options
    };
  }

  // Helper methods (simplified implementations)
  generateErrorId() {
    return `err_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
  }

  assessSeverity(error, context) {
    // Simplified severity assessment
    if (error.name === 'TypeError') return ERROR_SEVERITY.ERROR;
    if (error.name === 'ReferenceError') return ERROR_SEVERITY.CRITICAL;
    return ERROR_SEVERITY.WARNING;
  }

  calculateRiskScore(context) {
    // Simplified risk calculation
    return Math.random() * 0.5; // Demo value
  }

  delay(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
  }

  async retryOperation(errorRecord) {
    // Simplified retry logic
    return { success: true, retried: true };
  }

  async activateFallback(fallback, errorRecord) {
    // Simplified fallback activation
    return { fallbackActivated: true, component: fallback };
  }

  identifyDegradableFeatures(errorRecord) {
    return ['animations', 'advanced_ui', 'non_critical_apis'];
  }

  identifyEssentialFeatures(errorRecord) {
    return ['core_functionality', 'data_access', 'user_interface'];
  }

  async disableFeatures(features) {
    // Simplified feature disabling
    return { disabled: features };
  }

  async ensureEssentialFeatures(features) {
    // Simplified essential feature check
    return { ensured: features };
  }

  calculateErrorRate() {
    const recentErrors = this.errorHistory.filter(e => 
      Date.now() - e.timestamp < 60000 // Last minute
    );
    return recentErrors.length;
  }

  calculateRecoveryRate() {
    const recoveredErrors = this.errorHistory.filter(e => e.recovered);
    return this.errorHistory.length > 0 ? recoveredErrors.length / this.errorHistory.length : 0;
  }

  calculateMTTR() {
    const recoveredErrors = this.errorHistory.filter(e => e.recovered && e.recoveryTime);
    if (recoveredErrors.length === 0) return 0;
    
    const totalTime = recoveredErrors.reduce((sum, e) => sum + e.recoveryTime, 0);
    return totalTime / recoveredErrors.length;
  }

  calculateUserImpact(impact) {
    // Simplified user impact calculation
    return impact.severity * impact.affectedUsers;
  }

  calculateHealingSuccessRate() {
    const healingAttempts = this.errorHistory.filter(e => e.healingAttempted);
    const successfulHealing = healingAttempts.filter(e => e.healingSuccessful);

    return healingAttempts.length > 0 ? successfulHealing.length / healingAttempts.length : 0;
  }

  // Missing helper methods
  updateErrorPatterns(errorRecord) {
    const pattern = this.extractErrorPattern(errorRecord);
    const existing = this.errorPatterns.get(pattern) || { count: 0, lastSeen: 0 };

    this.errorPatterns.set(pattern, {
      count: existing.count + 1,
      lastSeen: Date.now(),
      errorType: errorRecord.error.name || 'Unknown'
    });
  }

  extractErrorPattern(errorRecord) {
    return `${errorRecord.error.name || 'Unknown'}_${errorRecord.context.component || 'Unknown'}`;
  }

  findKnownErrorPattern(error) {
    const pattern = `${error.name || 'Unknown'}_Unknown`;
    return this.errorPatterns.get(pattern);
  }

  getRecoveryStrategies(errorRecord) {
    return [
      { type: RECOVERY_STRATEGIES.RETRY, maxRetries: 3, delay: 1000 },
      { type: RECOVERY_STRATEGIES.FALLBACK, fallback: null },
      { type: RECOVERY_STRATEGIES.GRACEFUL_DEGRADATION }
    ];
  }

  recordSuccessfulStrategy(errorRecord, strategy) {
    // Record successful strategy for future use
    const pattern = this.extractErrorPattern(errorRecord);
    const existing = this.errorPatterns.get(pattern) || {};
    existing.successfulStrategy = strategy;
    this.errorPatterns.set(pattern, existing);
  }

  preventiveAction(context, riskScore) {
    // Simplified preventive action
    console.warn(`High risk detected (${riskScore}), taking preventive measures`);
  }

  getHistoricalErrorData(operation) {
    return { errorRate: 0.1, avgRecoveryTime: 1000 };
  }

  assessContextualRisk(context) {
    return 0.2; // Simplified risk assessment
  }

  combineRiskFactors(historical, contextual) {
    return (historical.errorRate + contextual) / 2;
  }

  classifyError(error) {
    return error.name || 'UnknownError';
  }

  identifyRootCause(error, context) {
    return 'Unknown root cause';
  }

  identifyAffectedSystems(error, context) {
    return ['component'];
  }

  selectHealingStrategy(diagnosis) {
    return { type: RECOVERY_STRATEGIES.RETRY, maxRetries: 2 };
  }

  async executeHealingStrategy(strategy, diagnosis) {
    // Simplified healing execution
    return { success: true, method: strategy.type };
  }

  recordSuccessfulHealing(diagnosis, strategy, result) {
    // Record successful healing for learning
  }

  escalateHealing(diagnosis, result) {
    // Escalate to higher level healing
    return { success: false, escalated: true };
  }

  updateHealingKnowledge(learningData) {
    // Update healing knowledge base
  }

  handleRecoveryFailure(errorRecord, recovery) {
    return { success: false, reason: 'Recovery failed', errorRecord };
  }

  handleCriticalFailure(errorRecord, recoveryError) {
    return { success: false, reason: 'Critical failure', errorRecord, recoveryError };
  }
}

/**
 * Error Boundary Decorator
 */
export function withErrorBoundary(errorConfig = {}) {
  return function(ComponentClass) {
    // Handle both class and function components
    if (typeof ComponentClass !== 'function') {
      throw new Error('withErrorBoundary decorator can only be applied to classes or functions');
    }

    // First apply principle validation
    const PrincipleAwareClass = withPrinciples({
      enabledPrinciples: ['RESILIENCE', 'PERFORMANCE'],
      metadata: { hasErrorHandling: true },
      ...errorConfig.principles
    })(ComponentClass);

    class ErrorBoundaryComponent extends PrincipleAwareClass {
      constructor(...args) {
        super(...args);

        this.errorBoundary = new AetherErrorBoundary({
          fallbackComponent: this.renderErrorFallback?.bind(this),
          onError: this.onError?.bind(this),
          ...errorConfig
        });

        this.setupErrorBoundary();
      }

      setupErrorBoundary() {
        // Wrap component methods with error handling
        const originalMethods = ['render', 'update', 'destroy'];

        originalMethods.forEach(methodName => {
          const originalMethod = this[methodName];
          if (originalMethod) {
            this[methodName] = async (...args) => {
              try {
                return await originalMethod.apply(this, args);
              } catch (error) {
                return this.errorBoundary.handleError(error, {
                  method: methodName,
                  component: this.constructor.name,
                  args
                });
              }
            };
          }
        });
      }

      renderErrorFallback(error, errorInfo) {
        return `<div class="error-fallback">
          <h3>Something went wrong</h3>
          <p>We're working to fix this issue.</p>
          <button onclick="location.reload()">Reload Page</button>
        </div>`;
      }

      getErrorBoundaryStatus() {
        return this.errorBoundary.getStatus();
      }
    }

    // Preserve original class name
    Object.defineProperty(ErrorBoundaryComponent, 'name', {
      value: `ErrorBoundary${ComponentClass.name}`,
      configurable: true
    });

    return ErrorBoundaryComponent;
  };
}

export default {
  AetherErrorBoundary,
  withErrorBoundary,
  ERROR_SEVERITY,
  RECOVERY_STRATEGIES
};