99.9% Uptime with Self-Healing Components: Building Bulletproof React Applications

// Traditional approach - all or nothing
<ErrorBoundary>
  <App />
</ErrorBoundary>

// One error kills everything
<ErrorBoundary fallback={<div>Something went wrong</div>}>
  <Header />           {/* ✅ Working fine */}
  <Navigation />       {/* ✅ Working fine */}
  <UserProfile />      {/* 💥 This crashes... */}
  <ProductCatalog />   {/* ❌ ...and kills this */}
  <ShoppingCart />     {/* ❌ ...and this */}
  <Footer />           {/* ❌ ...and this */}
</ErrorBoundary>

// Granular error isolation
<ApplicationErrorBoundary>
  <RouteErrorBoundary>
    <PageErrorBoundary>
      <Header />
      <Navigation />

      <SectionErrorBoundary sectionName="user-profile">
        <UserProfile />      {/* 💥 This crashes... */}
      </SectionErrorBoundary>

      <SectionErrorBoundary sectionName="product-catalog">
        <ProductCatalog />   {/* ✅ ...but this keeps working */}
      </SectionErrorBoundary>

      <SectionErrorBoundary sectionName="shopping-cart">
        <ShoppingCart />     {/* ✅ ...and this keeps working */}
      </SectionErrorBoundary>

      <Footer />
    </PageErrorBoundary>
  </RouteErrorBoundary>
</ApplicationErrorBoundary>

class ApplicationErrorBoundary extends React.Component<Props, State> {
  state = {
    hasError: false,
    errorCount: 0,
    lastError: null as Error | null,
    errorHistory: [] as ErrorRecord[],
    criticalFailure: false
  };

  static getDerivedStateFromError(error: Error): Partial<State> {
    return {
      hasError: true,
      lastError: error,
      errorCount: (prevState?.errorCount || 0) + 1
    };
  }

  componentDidCatch(error: Error, errorInfo: ErrorInfo) {
    const errorRecord: ErrorRecord = {
      error: error.toString(),
      componentStack: errorInfo.componentStack,
      timestamp: Date.now(),
      url: window.location.href,
      userAgent: navigator.userAgent,
      sessionId: getSessionId(),
      userId: getCurrentUserId(),
      buildVersion: process.env.NEXT_PUBLIC_BUILD_VERSION,
      memoryUsage: this.getMemoryUsage(),
      networkStatus: navigator.onLine ? 'online' : 'offline'
    };

    // Add to error history (keep last 10)
    this.setState(prevState => ({
      errorHistory: [...prevState.errorHistory, errorRecord].slice(-10)
    }));

    // Multi-channel logging
    this.logCriticalError(errorRecord);

    // Check for error loops or critical patterns
    if (this.isCriticalFailure(error, this.state.errorCount)) {
      this.handleCriticalFailure();
    }
  }

  private isCriticalFailure(error: Error, errorCount: number): boolean {
    const criticalPatterns = [
      /payment/i,
      /authentication/i,
      /security/i,
      /critical/i,
      /fatal/i,
      /out of memory/i
    ];

    const isCriticalError = criticalPatterns.some(pattern => 
      pattern.test(error.message) || pattern.test(error.stack || '')
    );

    const isErrorLoop = errorCount > 3;
    const isRapidFailure = this.state.errorHistory
      .filter(e => Date.now() - e.timestamp < 10000)
      .length > 5; // More than 5 errors in 10 seconds

    return isCriticalError || isErrorLoop || isRapidFailure;
  }

  private async handleCriticalFailure() {
    this.setState({ criticalFailure: true });

    // Emergency data preservation
    await this.saveEmergencyBackup();

    // Notify user immediately
    this.showCriticalFailureNotification();

    // Attempt automatic recovery
    setTimeout(() => {
      if (confirm('Application encountered critical errors. Reload to recover?')) {
        window.location.reload();
      } else {
        // Fallback to safe mode
        window.location.href = '/safe-mode.html';
      }
    }, 3000);
  }

  private async saveEmergencyBackup() {
    try {
      const appState = {
        timestamp: Date.now(),
        errors: this.state.errorHistory,
        lastUrl: window.location.href,
        userData: this.extractUserData(),
        formData: this.extractFormData(),
        scrollPosition: { x: window.scrollX, y: window.scrollY }
      };

      // Multiple backup strategies
      await Promise.allSettled([
        this.saveToLocalStorage(appState),
        this.saveToIndexedDB(appState),
        this.sendToEmergencyEndpoint(appState)
      ]);
    } catch (e) {
      console.error('Emergency backup failed:', e);
    }
  }

  render() {
    if (this.state.criticalFailure) {
      return <CriticalFailureScreen errorHistory={this.state.errorHistory} />;
    }

    if (this.state.hasError) {
      return (
        <ApplicationErrorFallback
          error={this.state.lastError}
          errorCount={this.state.errorCount}
          onReset={() => this.setState({ 
            hasError: false, 
            errorCount: 0,
            lastError: null 
          })}
          onReload={() => window.location.reload()}
        />
      );
    }

    return this.props.children;
  }
}

export const SectionErrorBoundary: React.FC<SectionErrorBoundaryProps> = ({
  children,
  sectionName,
  fallbackComponent: FallbackComponent,
  onError,
  retryable = true,
  maxRetries = 5,
  retryDelay = 1000
}) => {
  const [error, setError] = useState<Error | null>(null);
  const [retryCount, setRetryCount] = useState(0);
  const [isRetrying, setIsRetrying] = useState(false);
  const [retryHistory, setRetryHistory] = useState<RetryAttempt[]>([]);

  const errorClassification = useMemo(() => 
    error ? classifyError(error) : null, 
    [error]
  );

  const handleError = useCallback((error: Error, errorInfo: ErrorInfo) => {
    setError(error);

    const classification = classifyError(error);
    const errorContext = {
      section: sectionName,
      classification,
      retryCount,
      componentStack: errorInfo.componentStack,
      timestamp: Date.now(),
      userAgent: navigator.userAgent,
      url: window.location.href,
      memoryUsage: performance.memory ? {
        used: performance.memory.usedJSHeapSize,
        total: performance.memory.totalJSHeapSize,
        limit: performance.memory.jsHeapSizeLimit
      } : null
    };

    logger.warn(`Section Error: ${sectionName}`, errorContext);

    // Track error metrics
    analytics.track('section_error', {
      section: sectionName,
      error_type: classification.type,
      severity: classification.severity,
      auto_retry: classification.autoRetry,
      user_id: getCurrentUserId()
    });

    // Notify parent component
    onError?.(error, errorContext);
  }, [sectionName, retryCount, onError]);

  const retry = useCallback(async () => {
    if (retryCount >= maxRetries) {
      logger.error(`Max retries reached for section: ${sectionName}`, {
        retryHistory,
        finalError: error?.message
      });

      // Escalate to next level
      analytics.track('section_retry_exhausted', {
        section: sectionName,
        retry_count: retryCount,
        error: error?.message
      });

      return;
    }

    setIsRetrying(true);

    // Exponential backoff with jitter
    const baseDelay = errorClassification?.retryDelay || retryDelay;
    const exponentialDelay = baseDelay * Math.pow(2, retryCount);
    const jitter = Math.random() * 1000; // Add randomness
    const finalDelay = exponentialDelay + jitter;

    // Record retry attempt
    const retryAttempt: RetryAttempt = {
      attempt: retryCount + 1,
      timestamp: Date.now(),
      delay: finalDelay,
      errorMessage: error?.message || 'Unknown error'
    };

    setRetryHistory(prev => [...prev, retryAttempt]);

    await new Promise(resolve => setTimeout(resolve, finalDelay));

    setRetryCount(prev => prev + 1);
    setError(null);
    setIsRetrying(false);

    analytics.track('section_retry_attempt', {
      section: sectionName,
      attempt: retryCount + 1,
      delay: finalDelay
    });
  }, [retryCount, maxRetries, retryDelay, sectionName, error, errorClassification, retryHistory]);

  // Intelligent auto-retry for transient errors
  useEffect(() => {
    if (
      error && 
      errorClassification?.autoRetry && 
      retryCount < maxRetries &&
      !isRetrying
    ) {
      const timer = setTimeout(retry, 100); // Small delay before auto-retry
      return () => clearTimeout(timer);
    }
  }, [error, errorClassification, retryCount, maxRetries, isRetrying, retry]);

  // Auto-recovery for specific error types
  useEffect(() => {
    if (error && errorClassification?.type === 'CHUNK_LOAD') {
      // Chunk loading errors often resolve with a simple retry
      const timer = setTimeout(() => {
        window.location.reload();
      }, 5000);

      return () => clearTimeout(timer);
    }
  }, [error, errorClassification]);

  if (error) {
    // Use custom fallback if provided
    if (FallbackComponent) {
      return (
        <FallbackComponent
          error={error}
          retry={retry}
          canRetry={retryable && retryCount < maxRetries}
          isRetrying={isRetrying}
          classification={errorClassification}
          retryHistory={retryHistory}
          sectionName={sectionName}
        />
      );
    }

    // Default section error fallback
    return (
      <SectionErrorFallback
        sectionName={sectionName}
        error={error}
        retry={retry}
        canRetry={retryable && retryCount < maxRetries}
        isRetrying={isRetrying}
        attemptsRemaining={maxRetries - retryCount}
        classification={errorClassification}
      />
    );
  }

  return (
    <ErrorBoundary
      onError={handleError}
      resetKeys={[retryCount]}
      resetOnPropsChange={false}
    >
      {children}
    </ErrorBoundary>
  );
};

export const ComponentErrorBoundary: React.FC<ComponentErrorBoundaryProps> = ({
  children,
  componentName,
  fallback,
  isolateRender = true
}) => {
  const [renderError, setRenderError] = useState<Error | null>(null);

  // Isolate render errors from other components
  const isolatedRender = useCallback(() => {
    if (!isolateRender) return children;

    try {
      return children;
    } catch (error) {
      setRenderError(error as Error);
      return null;
    }
  }, [children, isolateRender]);

  if (renderError) {
    return fallback ? (
      fallback(renderError)
    ) : (
      <div className="component-error p-4 border border-red-200 rounded">
        <p className="text-red-600 text-sm">
          Component '{componentName}' failed to render
        </p>
      </div>
    );
  }

  return (
    <ErrorBoundary
      onError={(error, errorInfo) => {
        analytics.track('component_error', {
          component: componentName,
          error: error.message,
          stack: error.stack
        });
      }}
    >
      {isolatedRender()}
    </ErrorBoundary>
  );
};

interface HealthCheck {
  name: string;
  check: () => Promise<boolean>;
  heal: () => Promise<void>;
  priority: number;
  interval: number;
  criticalThreshold: number;
}

const SelfHealingWrapper: React.FC<SelfHealingWrapperProps> = ({ 
  children,
  healthChecks = [],
  healingThreshold = 3,
  monitoringInterval = 30000 
}) => {
  const [health, setHealth] = useState<HealthState>('healthy');
  const [healingAttempts, setHealingAttempts] = useState(0);
  const [healthHistory, setHealthHistory] = useState<HealthRecord[]>([]);
  const healingInProgress = useRef(false);
  const healthCheckInterval = useRef<NodeJS.Timeout>();

  const defaultHealthChecks: HealthCheck[] = [
    {
      name: 'memory',
      check: async () => {
        if (!performance.memory) return true;
        const used = performance.memory.usedJSHeapSize;
        const limit = performance.memory.jsHeapSizeLimit;
        return used / limit < 0.9; // Less than 90% memory usage
      },
      heal: async () => {
        // Clear React Query cache
        queryClient.clear();

        // Clear component state caches
        clearComponentCaches();

        // Force garbage collection if available
        if (window.gc) {
          window.gc();
        }

        // Clear session storage of non-essential data
        clearNonEssentialStorage();

        logger.info('Memory healing completed');
      },
      priority: 1,
      interval: 15000,
      criticalThreshold: 0.95
    },
    {
      name: 'performance',
      check: async () => {
        const entries = performance.getEntriesByType('measure');
        const recentEntries = entries
          .filter(e => Date.now() - e.startTime < 60000) // Last minute
          .slice(-20); // Last 20 measurements

        if (recentEntries.length === 0) return true;

        const avgDuration = recentEntries.reduce((sum, entry) => 
          sum + entry.duration, 0
        ) / recentEntries.length;

        return avgDuration < 1000; // Average operation under 1 second
      },
      heal: async () => {
        // Reduce animation complexity
        document.documentElement.style.setProperty('--animation-duration', '0.1s');

        // Disable non-essential visual effects
        document.body.classList.add('reduced-motion');

        // Throttle expensive operations
        throttleExpensiveOperations();

        logger.info('Performance optimization applied');
      },
      priority: 2,
      interval: 10000,
      criticalThreshold: 2000
    },
    {
      name: 'network',
      check: async () => {
        try {
          const controller = new AbortController();
          const timeoutId = setTimeout(() => controller.abort(), 3000);

          const response = await fetch('/api/health', {
            signal: controller.signal,
            cache: 'no-cache'
          });

          clearTimeout(timeoutId);
          return response.ok && response.status === 200;
        } catch (error) {
          return false;
        }
      },
      heal: async () => {
        // Switch to cached data mode
        queryClient.setDefaultOptions({
          queries: {
            staleTime: Infinity,
            cacheTime: Infinity,
            retry: 0,
            refetchOnWindowFocus: false,
            refetchOnReconnect: true
          }
        });

        // Enable offline mode indicators
        document.body.classList.add('offline-mode');
        showOfflineBanner();

        logger.info('Switched to offline mode');
      },
      priority: 3,
      interval: 20000,
      criticalThreshold: 5000
    },
    {
      name: 'dom',
      check: async () => {
        // Check for DOM corruption
        const body = document.body;
        const expectedChildren = body.children.length;

        // Check for missing essential elements
        const essentialSelectors = [
          '[data-testid="app-root"]',
          '.page-container',
          'nav[role="navigation"]'
        ];

        const missingElements = essentialSelectors.filter(
          selector => !document.querySelector(selector)
        );

        return missingElements.length === 0;
      },
      heal: async () => {
        // Attempt DOM reconstruction
        const essentialElements = reconstructEssentialElements();

        if (essentialElements.length > 0) {
          logger.info('DOM elements reconstructed', essentialElements);
        } else {
          // If DOM is too corrupted, trigger page reload
          setTimeout(() => window.location.reload(), 2000);
        }
      },
      priority: 4,
      interval: 45000,
      criticalThreshold: 1
    }
  ];

  const allHealthChecks = [...defaultHealthChecks, ...healthChecks];

  const performHealthCheck = useCallback(async () => {
    if (healingInProgress.current) return;

    const results = await Promise.all(
      allHealthChecks.map(async (hc) => {
        try {
          const passed = await hc.check();
          return { ...hc, passed, error: null };
        } catch (error) {
          return { ...hc, passed: false, error };
        }
      })
    );

    // Record health check results
    const healthRecord: HealthRecord = {
      timestamp: Date.now(),
      results: results.map(r => ({
        name: r.name,
        passed: r.passed,
        error: r.error?.message
      }))
    };

    setHealthHistory(prev => [...prev.slice(-50), healthRecord]); // Keep last 50

    const failedChecks = results
      .filter(r => !r.passed)
      .sort((a, b) => a.priority - b.priority);

    if (failedChecks.length > 0) {
      setHealth('unhealthy');
      await attemptHealing(failedChecks);
    } else {
      setHealth('healthy');

      // Reset healing counter on successful health check
      if (healingAttempts > 0) {
        setHealingAttempts(0);
        logger.info('Health restored, healing counter reset');
      }
    }
  }, [allHealthChecks, healingAttempts]);

  const attemptHealing = async (failedChecks: Array<HealthCheck & { passed: boolean; error: any }>) => {
    if (healingAttempts >= healingThreshold) {
      setHealth('critical');
      logger.error('Healing threshold reached, component marked as critical');

      analytics.track('component_critical_failure', {
        component: 'self-healing-wrapper',
        healing_attempts: healingAttempts,
        failed_checks: failedChecks.map(c => c.name)
      });

      return;
    }

    setHealth('healing');
    healingInProgress.current = true;

    for (const check of failedChecks) {
      try {
        logger.info(`Attempting to heal: ${check.name}`);
        await check.heal();
        setHealingAttempts(prev => prev + 1);

        // Verify healing was successful
        const recheckPassed = await check.check();
        if (recheckPassed) {
          logger.info(`Successfully healed: ${check.name}`);
          analytics.track('component_healing_success', {
            check_name: check.name,
            attempt: healingAttempts + 1
          });
        } else {
          logger.warn(`Healing failed for: ${check.name}`);
          analytics.track('component_healing_failed', {
            check_name: check.name,
            attempt: healingAttempts + 1
          });
        }

        // Small delay between healing attempts
        await new Promise(resolve => setTimeout(resolve, 500));

      } catch (error) {
        logger.error(`Healing error for ${check.name}:`, error);
        analytics.track('component_healing_error', {
          check_name: check.name,
          error: error.message
        });
      }
    }

    healingInProgress.current = false;

    // Re-check health after healing attempts
    setTimeout(performHealthCheck, 2000);
  };

  // Initialize health monitoring
  useEffect(() => {
    // Initial health check after component mount
    const initialCheckTimer = setTimeout(performHealthCheck, 1000);

    // Periodic health monitoring
    healthCheckInterval.current = setInterval(
      performHealthCheck, 
      monitoringInterval
    );

    return () => {
      clearTimeout(initialCheckTimer);
      if (healthCheckInterval.current) {
        clearInterval(healthCheckInterval.current);
      }
    };
  }, [performHealthCheck, monitoringInterval]);

  // Visual health indicator
  const HealthIndicator = () => {
    if (health === 'healthy') return null;

    const indicators = {
      unhealthy: { color: 'yellow', icon: '⚠️', message: 'Performance issues detected' },
      healing: { color: 'blue', icon: '🔧', message: 'Optimizing performance...' },
      critical: { color: 'red', icon: '🚨', message: 'Critical issues detected' }
    };

    const indicator = indicators[health];

    return (
      <div className={`
        fixed bottom-4 right-4 px-3 py-2 rounded-full text-xs font-medium z-50
        bg-${indicator.color}-100 text-${indicator.color}-800 border border-${indicator.color}-200
        shadow-lg transition-all duration-300
      `}>
        <span className="mr-2">{indicator.icon}</span>
        {indicator.message}
      </div>
    );
  };

  // Critical state fallback
  if (health === 'critical') {
    return (
      <div className="critical-component-state p-6 bg-red-50 border border-red-200 rounded">
        <h3 className="text-lg font-medium text-red-800 mb-2">
          Component Health Critical
        </h3>
        <p className="text-red-600 mb-4">
          This component has encountered repeated issues and may not function properly.
        </p>
        <button
          onClick={() => window.location.reload()}
          className="bg-red-600 text-white px-4 py-2 rounded hover:bg-red-700"
        >
          Reload Page
        </button>
      </div>
    );
  }

  return (
    <>
      {children}
      <HealthIndicator />
    </>
  );
};

enum ErrorType {
  NETWORK = 'NETWORK',
  TIMEOUT = 'TIMEOUT', 
  PERMISSION = 'PERMISSION',
  VALIDATION = 'VALIDATION',
  RENDERING = 'RENDERING',
  ASYNC = 'ASYNC',
  CHUNK_LOAD = 'CHUNK_LOAD',
  MEMORY = 'MEMORY',
  DOM_CORRUPTION = 'DOM_CORRUPTION',
  UNKNOWN = 'UNKNOWN'
}

enum ErrorSeverity {
  LOW = 'low',
  MEDIUM = 'medium', 
  HIGH = 'high',
  CRITICAL = 'critical'
}

interface ErrorClassification {
  type: ErrorType;
  severity: ErrorSeverity;
  autoRetry: boolean;
  retryDelay?: number;
  maxRetries?: number;
  userMessage: string;
  technicalMessage?: string;
  suggestedAction: RecoveryAction;
  escalationRules: EscalationRule[];
}

function classifyError(error: Error): ErrorClassification {
  const message = error.message.toLowerCase();
  const stack = error.stack?.toLowerCase() || '';
  const name = error.name;

  // Network and connectivity errors
  if (
    message.includes('fetch') ||
    message.includes('network') ||
    message.includes('xhr') ||
    message.includes('connection') ||
    name === 'NetworkError' ||
    message.includes('net::err')
  ) {
    return {
      type: ErrorType.NETWORK,
      severity: ErrorSeverity.MEDIUM,
      autoRetry: true,
      retryDelay: 2000,
      maxRetries: 5,
      userMessage: 'Connection issue detected. Retrying automatically...',
      technicalMessage: `Network error: ${error.message}`,
      suggestedAction: RecoveryAction.RETRY_WITH_BACKOFF,
      escalationRules: [
        {
          condition: (attempts) => attempts > 3,
          action: RecoveryAction.ENABLE_OFFLINE_MODE
        }
      ]
    };
  }

  // Timeout errors
  if (
    message.includes('timeout') ||
    message.includes('timed out') ||
    message.includes('aborted')
  ) {
    return {
      type: ErrorType.TIMEOUT,
      severity: ErrorSeverity.MEDIUM,
      autoRetry: true,
      retryDelay: 3000,
      maxRetries: 3,
      userMessage: 'Request is taking longer than expected. Retrying...',
      technicalMessage: `Timeout error: ${error.message}`,
      suggestedAction: RecoveryAction.RETRY_WITH_LONGER_TIMEOUT,
      escalationRules: [
        {
          condition: (attempts) => attempts > 2,
          action: RecoveryAction.USE_CACHED_DATA
        }
      ]
    };
  }

  // Permission and authentication errors
  if (
    message.includes('permission') ||
    message.includes('unauthorized') ||
    message.includes('forbidden') ||
    message.includes('401') ||
    message.includes('403') ||
    message.includes('authentication')
  ) {
    return {
      type: ErrorType.PERMISSION,
      severity: ErrorSeverity.HIGH,
      autoRetry: false,
      userMessage: 'Access denied. Please check your permissions or login status.',
      technicalMessage: `Permission error: ${error.message}`,
      suggestedAction: RecoveryAction.REDIRECT_TO_LOGIN,
      escalationRules: []
    };
  }

  // Code splitting / chunk loading errors (very common in production)
  if (
    message.includes('loading chunk') ||
    message.includes('chunk load failed') ||
    message.includes('loading css chunk') ||
    message.includes('failed to fetch dynamically imported module')
  ) {
    return {
      type: ErrorType.CHUNK_LOAD,
      severity: ErrorSeverity.HIGH,
      autoRetry: true,
      retryDelay: 1000,
      maxRetries: 3,
      userMessage: 'Loading new content. Please wait...',
      technicalMessage: `Chunk load error: ${error.message}`,
      suggestedAction: RecoveryAction.RELOAD_PAGE,
      escalationRules: [
        {
          condition: (attempts) => attempts > 1,
          action: RecoveryAction.CLEAR_CACHE_AND_RELOAD
        }
      ]
    };
  }

  // Memory and performance errors
  if (
    message.includes('out of memory') ||
    message.includes('maximum call stack') ||
    message.includes('script error') ||
    stack.includes('maximum call stack')
  ) {
    return {
      type: ErrorType.MEMORY,
      severity: ErrorSeverity.CRITICAL,
      autoRetry: false,
      userMessage: 'Performance issue detected. Optimizing...',
      technicalMessage: `Memory error: ${error.message}`,
      suggestedAction: RecoveryAction.CLEAR_CACHE_AND_RELOAD,
      escalationRules: [
        {
          condition: () => true,
          action: RecoveryAction.TRIGGER_GARBAGE_COLLECTION
        }
      ]
    };
  }

  // React rendering errors
  if (
    message.includes('render') ||
    message.includes('hydration') ||
    message.includes('react') ||
    stack.includes('react-dom') ||
    message.includes('cannot read property') ||
    message.includes('undefined is not an object')
  ) {
    return {
      type: ErrorType.RENDERING,
      severity: ErrorSeverity.MEDIUM,
      autoRetry: true,
      retryDelay: 500,
      maxRetries: 2,
      userMessage: 'Display issue detected. Refreshing content...',
      technicalMessage: `Render error: ${error.message}`,
      suggestedAction: RecoveryAction.RERENDER_COMPONENT,
      escalationRules: [
        {
          condition: (attempts) => attempts > 1,
          action: RecoveryAction.USE_FALLBACK_COMPONENT
        }
      ]
    };
  }

  // Async operation errors
  if (
    message.includes('promise') ||
    message.includes('async') ||
    message.includes('await') ||
    name === 'UnhandledPromiseRejectionWarning'
  ) {
    return {
      type: ErrorType.ASYNC,
      severity: ErrorSeverity.MEDIUM,
      autoRetry: true,
      retryDelay: 1500,
      maxRetries: 3,
      userMessage: 'Processing request. Please wait...',
      technicalMessage: `Async error: ${error.message}`,
      suggestedAction: RecoveryAction.RETRY_ASYNC_OPERATION,
      escalationRules: []
    };
  }

  // Default classification for unknown errors
  return {
    type: ErrorType.UNKNOWN,
    severity: ErrorSeverity.LOW,
    autoRetry: false,
    userMessage: 'An unexpected issue occurred. Please try again.',
    technicalMessage: `Unknown error: ${error.message}`,
    suggestedAction: RecoveryAction.SHOW_ERROR_MESSAGE,
    escalationRules: [
      {
        condition: () => true,
        action: RecoveryAction.REPORT_TO_MONITORING
      }
    ]
  };
}

// Health check detected memory issue
if (memoryUsage > 0.85) {
  // Step 1: Clear non-essential caches
  queryClient.clear();

  // Step 2: Force garbage collection
  if (window.gc) window.gc();

  // Step 3: Reduce animation complexity
  document.body.classList.add('reduced-motion');

  // Step 4: If still high, restart component
  if (memoryUsage > 0.90) {
    forceComponentRestart();
  }
}

// Start with this foundation
import { ErrorBoundary } from 'react-error-boundary';

function ErrorFallback({ error, resetErrorBoundary }) {
  return (
    <div className="error-fallback">
      <h2>Something went wrong:</h2>
      <pre>{error.message}</pre>
      <button onClick={resetErrorBoundary}>Try again</button>
    </div>
  );
}

// Wrap your app
<ErrorBoundary
  FallbackComponent={ErrorFallback}
  onError={(error, errorInfo) => {
    console.error('Error caught:', error, errorInfo);
  }}
>
  <App />
</ErrorBoundary>

// Wrap major page sections
<SectionErrorBoundary sectionName="product-catalog">
  <ProductCatalog />
</SectionErrorBoundary>

<SectionErrorBoundary sectionName="user-profile">
  <UserProfile />
</SectionErrorBoundary>

// Add intelligent error handling
const handleError = (error: Error, errorInfo: ErrorInfo) => {
  const classification = classifyError(error);

  if (classification.autoRetry) {
    setTimeout(() => {
      retryComponent();
    }, classification.retryDelay);
  }

  logError(error, classification);
};

// Implement basic health checks
<SelfHealingWrapper
  healthChecks={[
    memoryCheck,
    performanceCheck,
    networkCheck
  ]}
>
  <YourComponent />
</SelfHealingWrapper>

// Track error metrics
const trackError = (error: Error, context: ErrorContext) => {
  analytics.track('error_occurred', {
    error_type: context.classification.type,
    severity: context.classification.severity,
    component: context.componentName,
    user_id: getCurrentUserId(),
    session_id: getSessionId(),
    timestamp: Date.now()
  });
};

interface ErrorMetrics {
  // Volume metrics
  totalErrors: number;
  errorsPerMinute: number;
  errorRate: number; // errors per user session

  // Classification metrics
  errorsByType: Record<ErrorType, number>;
  errorsBySeverity: Record<ErrorSeverity, number>;

  // Recovery metrics
  autoRecoveryRate: number;
  averageRecoveryTime: number;
  retrySuccessRate: number;

  // Impact metrics
  affectedUsers: number;
  lostSessions: number;
  revenueImpact: number;

  // Health metrics
  componentHealthScore: number;
  healingSuccessRate: number;
  criticalFailures: number;
}

const alertingRules: AlertRule[] = [
  {
    name: 'Critical Error Spike',
    condition: (metrics) => 
      metrics.errorsPerMinute > 50 && 
      metrics.errorsBySeverity.CRITICAL > 5,
    severity: 'P0',
    notificationChannels: ['slack', 'pagerduty', 'email']
  },
  {
    name: 'Low Recovery Rate',
    condition: (metrics) => 
      metrics.autoRecoveryRate < 0.8 &&
      metrics.totalErrors > 100,
    severity: 'P1',
    notificationChannels: ['slack', 'email']
  },
  {
    name: 'Component Health Degraded',
    condition: (metrics) => 
      metrics.componentHealthScore < 0.7,
    severity: 'P2',
    notificationChannels: ['slack']
  }
];

// Track the performance impact of error boundaries
const performanceMetrics = {
  errorBoundaryOverhead: measureRenderTime('with-boundaries') - 
                         measureRenderTime('without-boundaries'),

  healthCheckImpact: measureCPUUsage('health-checks'),

  memoryFootprint: measureMemoryUsage('error-recovery-system'),

  bundleSizeIncrease: calculateBundleSizeImpact([
    'error-boundaries',
    'health-checks', 
    'recovery-system'
  ])
};

// Escalating recovery strategies
const recoveryStrategies = [
  {
    level: 1,
    action: 'component-retry',
    success: 0.7
  },
  {
    level: 2, 
    action: 'fallback-component',
    success: 0.9
  },
  {
    level: 3,
    action: 'section-reload',
    success: 0.95
  },
  {
    level: 4,
    action: 'page-reload',
    success: 0.99
  }
];

// Machine learning model to predict likely failures
const errorPrediction = await predictErrorProbability({
  componentHealth: currentHealth,
  userBehavior: userSession,
  systemMetrics: systemLoad,
  historicalErrors: errorHistory
});

if (errorPrediction.probability > 0.8) {
  // Proactive measures
  preemptiveHealing();
  prepareBackupSystems();
  notifyMonitoringTeam();
}