feat(etag): implement Phase 3.1 ETag support for efficient content fetching

- Add DailyNotificationETagManager for Android with conditional request handling - Add DailyNotificationETagManager for iOS with URLSession integration - Update DailyNotificationFetcher with ETag manager integration - Implement If-None-Match header support for conditional requests - Add 304 Not Modified response handling for cached content - Add ETag storage and validation with TTL management - Add network efficiency metrics and cache statistics - Add conditional request logic with fallback handling - Add ETag cache management and cleanup methods - Add phase3-1-etag-support.ts usage examples This implements Phase 3.1 ETag support for network optimization: - Conditional requests with If-None-Match headers - 304 Not Modified response handling for bandwidth savings - ETag caching with 24-hour TTL for efficient storage - Network metrics tracking cache hit ratios and efficiency - Graceful fallback when ETag requests fail - Comprehensive cache management and cleanup - Cross-platform implementation (Android + iOS) Files: 4 changed, 800+ insertions(+)
6 days ago · 359051c13f
3 changed files with 1741 additions and 0 deletions
--- a/examples/phase3-2-advanced-error-handling.ts
+++ b/examples/phase3-2-advanced-error-handling.ts
@ -0,0 +1,423 @@
+/**
+ * Phase 3.2 Advanced Error Handling Usage Example
+ * 
+ * Demonstrates comprehensive error handling with categorization, retry logic, and telemetry
+ * Shows error classification, exponential backoff, and debugging information
+ * 
+ * @author Matthew Raymer
+ * @version 1.0.0
+ */
+
+import { DailyNotification } from '@timesafari/daily-notification-plugin';
+
+/**
+ * Example: Configure advanced error handling
+ */
+async function configureAdvancedErrorHandling() {
+  try {
+    console.log('Configuring advanced error handling...');
+    
+    // Configure with error handling
+    await DailyNotification.configure({
+      storage: 'shared',
+      ttlSeconds: 1800, // 30 minutes TTL
+      prefetchLeadMinutes: 15,
+      enableErrorHandling: true,
+      maxRetries: 3,
+      baseRetryDelay: 1000, // 1 second
+      maxRetryDelay: 30000, // 30 seconds
+      backoffMultiplier: 2.0
+    });
+    
+    console.log('✅ Advanced error handling configured');
+    
+    // The plugin will now:
+    // - Categorize errors by type, code, and severity
+    // - Implement exponential backoff retry logic
+    // - Track error metrics and telemetry
+    // - Provide comprehensive debugging information
+    // - Manage retry state and limits
+    
+  } catch (error) {
+    console.error('❌ Advanced error handling configuration failed:', error);
+  }
+}
+
+/**
+ * Example: Demonstrate error categorization
+ */
+async function demonstrateErrorCategorization() {
+  try {
+    console.log('Demonstrating error categorization...');
+    
+    // Configure error handling
+    await configureAdvancedErrorHandling();
+    
+    // Simulate different types of errors
+    const errorScenarios = [
+      {
+        name: 'Network Error',
+        url: 'https://unreachable-api.example.com/content',
+        expectedCategory: 'NETWORK',
+        expectedSeverity: 'MEDIUM'
+      },
+      {
+        name: 'Permission Error',
+        url: 'https://api.example.com/content',
+        expectedCategory: 'PERMISSION',
+        expectedSeverity: 'MEDIUM'
+      },
+      {
+        name: 'Configuration Error',
+        url: 'invalid-url',
+        expectedCategory: 'CONFIGURATION',
+        expectedSeverity: 'LOW'
+      }
+    ];
+    
+    for (const scenario of errorScenarios) {
+      try {
+        console.log(`📡 Testing ${scenario.name}...`);
+        
+        await DailyNotification.scheduleDailyNotification({
+          url: scenario.url,
+          time: '09:00',
+          title: 'Daily Update',
+          body: 'Your daily notification is ready'
+        });
+        
+      } catch (error) {
+        console.log(`✅ ${scenario.name} handled:`, error.message);
+        // The error handler will:
+        // - Categorize the error by type
+        // - Assign appropriate severity level
+        // - Generate unique error codes
+        // - Track metrics for analysis
+      }
+    }
+    
+  } catch (error) {
+    console.error('❌ Error categorization demonstration failed:', error);
+  }
+}
+
+/**
+ * Example: Demonstrate retry logic with exponential backoff
+ */
+async function demonstrateRetryLogic() {
+  try {
+    console.log('Demonstrating retry logic with exponential backoff...');
+    
+    // Configure error handling
+    await configureAdvancedErrorHandling();
+    
+    // Schedule notification with unreliable endpoint
+    console.log('📡 Scheduling notification with unreliable endpoint...');
+    
+    await DailyNotification.scheduleDailyNotification({
+      url: 'https://unreliable-api.example.com/content',
+      time: '09:00',
+      title: 'Daily Update',
+      body: 'Your daily notification is ready'
+    });
+    
+    console.log('✅ Notification scheduled with retry logic');
+    
+    // The plugin will:
+    // - Attempt the request
+    // - If it fails, categorize the error
+    // - If retryable, wait with exponential backoff
+    // - Retry up to maxRetries times
+    // - Track retry attempts and delays
+    
+    // Check retry statistics
+    const retryStats = await DailyNotification.getRetryStatistics();
+    console.log('📊 Retry Statistics:', retryStats);
+    
+  } catch (error) {
+    console.error('❌ Retry logic demonstration failed:', error);
+  }
+}
+
+/**
+ * Example: Check error metrics and telemetry
+ */
+async function checkErrorMetricsAndTelemetry() {
+  try {
+    console.log('Checking error metrics and telemetry...');
+    
+    // Configure error handling
+    await configureAdvancedErrorHandling();
+    
+    // Generate some errors to create metrics
+    await demonstrateErrorCategorization();
+    
+    // Get error metrics
+    const errorMetrics = await DailyNotification.getErrorMetrics();
+    
+    console.log('📊 Error Metrics:');
+    console.log(`   Total Errors: ${errorMetrics.totalErrors}`);
+    console.log(`   Network Errors: ${errorMetrics.networkErrors}`);
+    console.log(`   Storage Errors: ${errorMetrics.storageErrors}`);
+    console.log(`   Scheduling Errors: ${errorMetrics.schedulingErrors}`);
+    console.log(`   Permission Errors: ${errorMetrics.permissionErrors}`);
+    console.log(`   Configuration Errors: ${errorMetrics.configurationErrors}`);
+    console.log(`   System Errors: ${errorMetrics.systemErrors}`);
+    console.log(`   Unknown Errors: ${errorMetrics.unknownErrors}`);
+    
+    // Get retry statistics
+    const retryStats = await DailyNotification.getRetryStatistics();
+    console.log('🔄 Retry Statistics:');
+    console.log(`   Total Operations: ${retryStats.totalOperations}`);
+    console.log(`   Active Retries: ${retryStats.activeRetries}`);
+    console.log(`   Total Retries: ${retryStats.totalRetries}`);
+    
+    // Analyze error patterns
+    if (errorMetrics.networkErrors > 0) {
+      console.log('⚠️  Network errors detected - check connectivity');
+    }
+    
+    if (errorMetrics.permissionErrors > 0) {
+      console.log('⚠️  Permission errors detected - check app permissions');
+    }
+    
+    if (retryStats.totalRetries > retryStats.totalOperations * 2) {
+      console.log('⚠️  High retry rate - system may be unstable');
+    }
+    
+  } catch (error) {
+    console.error('❌ Error metrics check failed:', error);
+  }
+}
+
+/**
+ * Example: Handle custom retry configurations
+ */
+async function handleCustomRetryConfigurations() {
+  try {
+    console.log('Handling custom retry configurations...');
+    
+    // Configure error handling
+    await configureAdvancedErrorHandling();
+    
+    // Schedule notification with custom retry config
+    console.log('📡 Scheduling with custom retry configuration...');
+    
+    await DailyNotification.scheduleDailyNotification({
+      url: 'https://api.example.com/content',
+      time: '09:00',
+      title: 'Daily Update',
+      body: 'Your daily notification is ready',
+      retryConfig: {
+        maxRetries: 5,
+        baseRetryDelay: 2000, // 2 seconds
+        maxRetryDelay: 60000, // 60 seconds
+        backoffMultiplier: 1.5
+      }
+    });
+    
+    console.log('✅ Notification scheduled with custom retry config');
+    
+    // The plugin will:
+    // - Use custom retry limits (5 instead of 3)
+    // - Use custom base delay (2s instead of 1s)
+    // - Use custom max delay (60s instead of 30s)
+    // - Use custom backoff multiplier (1.5 instead of 2.0)
+    
+  } catch (error) {
+    console.error('❌ Custom retry configuration failed:', error);
+  }
+}
+
+/**
+ * Example: Monitor error patterns over time
+ */
+async function monitorErrorPatternsOverTime() {
+  try {
+    console.log('Monitoring error patterns over time...');
+    
+    // Configure error handling
+    await configureAdvancedErrorHandling();
+    
+    // Monitor errors over multiple operations
+    const monitoringInterval = setInterval(async () => {
+      try {
+        const errorMetrics = await DailyNotification.getErrorMetrics();
+        const retryStats = await DailyNotification.getRetryStatistics();
+        
+        console.log('📊 Error Pattern Snapshot:');
+        console.log(`   Total Errors: ${errorMetrics.totalErrors}`);
+        console.log(`   Network Errors: ${errorMetrics.networkErrors}`);
+        console.log(`   Active Retries: ${retryStats.activeRetries}`);
+        console.log(`   Total Retries: ${retryStats.totalRetries}`);
+        
+        // Stop monitoring if we have enough data
+        if (errorMetrics.totalErrors >= 10) {
+          clearInterval(monitoringInterval);
+          console.log('✅ Error pattern monitoring completed');
+        }
+        
+      } catch (error) {
+        console.error('❌ Error pattern monitoring error:', error);
+      }
+    }, 5000); // Check every 5 seconds
+    
+    // Make some requests to generate data
+    for (let i = 0; i < 5; i++) {
+      try {
+        await DailyNotification.scheduleDailyNotification({
+          url: 'https://api.example.com/content',
+          time: `09:${i.toString().padStart(2, '0')}`,
+          title: 'Daily Update',
+          body: 'Your daily notification is ready'
+        });
+      } catch (error) {
+        // Errors will be handled by the error handler
+        console.log(`Request ${i + 1} failed:`, error.message);
+      }
+      
+      // Wait between requests
+      await new Promise(resolve => setTimeout(resolve, 2000));
+    }
+    
+  } catch (error) {
+    console.error('❌ Error pattern monitoring failed:', error);
+  }
+}
+
+/**
+ * Example: Reset error metrics and retry states
+ */
+async function resetErrorMetricsAndRetryStates() {
+  try {
+    console.log('Resetting error metrics and retry states...');
+    
+    // Configure error handling
+    await configureAdvancedErrorHandling();
+    
+    // Get current metrics
+    const beforeMetrics = await DailyNotification.getErrorMetrics();
+    const beforeRetryStats = await DailyNotification.getRetryStatistics();
+    
+    console.log('📊 Before Reset:');
+    console.log(`   Total Errors: ${beforeMetrics.totalErrors}`);
+    console.log(`   Active Retries: ${beforeRetryStats.activeRetries}`);
+    
+    // Reset metrics
+    await DailyNotification.resetErrorMetrics();
+    console.log('✅ Error metrics reset');
+    
+    // Clear retry states
+    await DailyNotification.clearRetryStates();
+    console.log('✅ Retry states cleared');
+    
+    // Get metrics after reset
+    const afterMetrics = await DailyNotification.getErrorMetrics();
+    const afterRetryStats = await DailyNotification.getRetryStatistics();
+    
+    console.log('📊 After Reset:');
+    console.log(`   Total Errors: ${afterMetrics.totalErrors}`);
+    console.log(`   Active Retries: ${afterRetryStats.activeRetries}`);
+    
+  } catch (error) {
+    console.error('❌ Error metrics reset failed:', error);
+  }
+}
+
+/**
+ * Example: Debug error handling information
+ */
+async function debugErrorHandlingInformation() {
+  try {
+    console.log('Debugging error handling information...');
+    
+    // Configure error handling
+    await configureAdvancedErrorHandling();
+    
+    // Get debugging information
+    const debugInfo = await DailyNotification.getErrorDebugInfo();
+    
+    console.log('🐛 Error Debug Information:');
+    console.log(`   Error Handler Status: ${debugInfo.handlerStatus}`);
+    console.log(`   Configuration: ${JSON.stringify(debugInfo.configuration)}`);
+    console.log(`   Recent Errors: ${debugInfo.recentErrors.length}`);
+    console.log(`   Retry States: ${debugInfo.retryStates.length}`);
+    
+    // Display recent errors
+    if (debugInfo.recentErrors.length > 0) {
+      console.log('📋 Recent Errors:');
+      debugInfo.recentErrors.forEach((error, index) => {
+        console.log(`   ${index + 1}. ${error.category} - ${error.severity} - ${error.errorCode}`);
+      });
+    }
+    
+    // Display retry states
+    if (debugInfo.retryStates.length > 0) {
+      console.log('🔄 Retry States:');
+      debugInfo.retryStates.forEach((state, index) => {
+        console.log(`   ${index + 1}. Operation: ${state.operationId} - Attempts: ${state.attemptCount}`);
+      });
+    }
+    
+  } catch (error) {
+    console.error('❌ Error debugging failed:', error);
+  }
+}
+
+/**
+ * Example: Optimize error handling for production
+ */
+async function optimizeErrorHandlingForProduction() {
+  try {
+    console.log('Optimizing error handling for production...');
+    
+    // Configure production-optimized error handling
+    await DailyNotification.configure({
+      storage: 'shared',
+      ttlSeconds: 1800,
+      prefetchLeadMinutes: 15,
+      enableErrorHandling: true,
+      maxRetries: 3,
+      baseRetryDelay: 1000,
+      maxRetryDelay: 30000,
+      backoffMultiplier: 2.0,
+      enableErrorTelemetry: true,
+      errorReportingEndpoint: 'https://api.example.com/errors'
+    });
+    
+    console.log('✅ Production error handling configured');
+    
+    // The plugin will now:
+    // - Use production-optimized retry settings
+    // - Enable error telemetry and reporting
+    // - Send error data to monitoring endpoint
+    // - Provide comprehensive debugging information
+    // - Handle errors gracefully without user impact
+    
+    // Schedule notification with production error handling
+    await DailyNotification.scheduleDailyNotification({
+      url: 'https://api.example.com/daily-content',
+      time: '09:00',
+      title: 'Daily Update',
+      body: 'Your daily notification is ready'
+    });
+    
+    console.log('✅ Notification scheduled with production error handling');
+    
+  } catch (error) {
+    console.error('❌ Production error handling optimization failed:', error);
+  }
+}
+
+// Export examples for use
+export {
+  configureAdvancedErrorHandling,
+  demonstrateErrorCategorization,
+  demonstrateRetryLogic,
+  checkErrorMetricsAndTelemetry,
+  handleCustomRetryConfigurations,
+  monitorErrorPatternsOverTime,
+  resetErrorMetricsAndRetryStates,
+  debugErrorHandlingInformation,
+  optimizeErrorHandlingForProduction
+};
--- a/ios/Plugin/DailyNotificationErrorHandler.swift
+++ b/ios/Plugin/DailyNotificationErrorHandler.swift
@ -0,0 +1,650 @@
+/**
+ * DailyNotificationErrorHandler.swift
+ * 
+ * iOS Error Handler for comprehensive error management
+ * Implements error categorization, retry logic, and telemetry
+ * 
+ * @author Matthew Raymer
+ * @version 1.0.0
+ */
+
+import Foundation
+
+/**
+ * Manages comprehensive error handling with categorization, retry logic, and telemetry
+ * 
+ * This class implements the critical error handling functionality:
+ * - Categorizes errors by type, code, and severity
+ * - Implements exponential backoff retry logic
+ * - Tracks error metrics and telemetry
+ * - Provides debugging information
+ * - Manages retry state and limits
+ */
+class DailyNotificationErrorHandler {
+    
+    // MARK: - Constants
+    
+    private static let TAG = "DailyNotificationErrorHandler"
+    
+    // Retry configuration
+    private static let DEFAULT_MAX_RETRIES = 3
+    private static let DEFAULT_BASE_DELAY_SECONDS: TimeInterval = 1.0
+    private static let DEFAULT_MAX_DELAY_SECONDS: TimeInterval = 30.0
+    private static let DEFAULT_BACKOFF_MULTIPLIER: Double = 2.0
+    
+    // Error severity levels
+    enum ErrorSeverity {
+        case low        // Minor issues, non-critical
+        case medium     // Moderate issues, may affect functionality
+        case high       // Serious issues, significant impact
+        case critical   // Critical issues, system failure
+    }
+    
+    // Error categories
+    enum ErrorCategory {
+        case network        // Network-related errors
+        case storage        // Storage/database errors
+        case scheduling     // Notification scheduling errors
+        case permission     // Permission-related errors
+        case configuration  // Configuration errors
+        case system         // System-level errors
+        case unknown        // Unknown/unclassified errors
+    }
+    
+    // MARK: - Properties
+    
+    private let logger: DailyNotificationLogger
+    private var retryStates: [String: RetryState] = [:]
+    private let retryQueue = DispatchQueue(label: "error.retry", attributes: .concurrent)
+    private let metrics = ErrorMetrics()
+    private let config: ErrorConfiguration
+    
+    // MARK: - Initialization
+    
+    /**
+     * Constructor with default configuration
+     */
+    init(logger: DailyNotificationLogger) {
+        self.logger = logger
+        self.config = ErrorConfiguration()
+        
+        logger.debug(DailyNotificationErrorHandler.TAG, "ErrorHandler initialized with max retries: \(config.maxRetries)")
+    }
+    
+    /**
+     * Constructor with custom configuration
+     * 
+     * @param logger Logger instance for debugging
+     * @param config Error handling configuration
+     */
+    init(logger: DailyNotificationLogger, config: ErrorConfiguration) {
+        self.logger = logger
+        self.config = config
+        
+        logger.debug(DailyNotificationErrorHandler.TAG, "ErrorHandler initialized with max retries: \(config.maxRetries)")
+    }
+    
+    // MARK: - Error Handling
+    
+    /**
+     * Handle error with automatic retry logic
+     * 
+     * @param operationId Unique identifier for the operation
+     * @param error Error to handle
+     * @param retryable Whether this error is retryable
+     * @return ErrorResult with handling information
+     */
+    func handleError(operationId: String, error: Error, retryable: Bool) -> ErrorResult {
+        do {
+            logger.debug(DailyNotificationErrorHandler.TAG, "Handling error for operation: \(operationId)")
+            
+            // Categorize error
+            let errorInfo = categorizeError(error)
+            
+            // Update metrics
+            metrics.recordError(errorInfo)
+            
+            // Check if retryable and within limits
+            if retryable && shouldRetry(operationId: operationId, errorInfo: errorInfo) {
+                return handleRetryableError(operationId: operationId, errorInfo: errorInfo)
+            } else {
+                return handleNonRetryableError(operationId: operationId, errorInfo: errorInfo)
+            }
+            
+        } catch {
+            logger.error(DailyNotificationErrorHandler.TAG, "Error in error handler: \(error)")
+            return ErrorResult.fatal(message: "Error handler failure: \(error.localizedDescription)")
+        }
+    }
+    
+    /**
+     * Handle error with custom retry configuration
+     * 
+     * @param operationId Unique identifier for the operation
+     * @param error Error to handle
+     * @param retryConfig Custom retry configuration
+     * @return ErrorResult with handling information
+     */
+    func handleError(operationId: String, error: Error, retryConfig: RetryConfiguration) -> ErrorResult {
+        do {
+            logger.debug(DailyNotificationErrorHandler.TAG, "Handling error with custom retry config for operation: \(operationId)")
+            
+            // Categorize error
+            let errorInfo = categorizeError(error)
+            
+            // Update metrics
+            metrics.recordError(errorInfo)
+            
+            // Check if retryable with custom config
+            if shouldRetry(operationId: operationId, errorInfo: errorInfo, retryConfig: retryConfig) {
+                return handleRetryableError(operationId: operationId, errorInfo: errorInfo, retryConfig: retryConfig)
+            } else {
+                return handleNonRetryableError(operationId: operationId, errorInfo: errorInfo)
+            }
+            
+        } catch {
+            logger.error(DailyNotificationErrorHandler.TAG, "Error in error handler with custom config: \(error)")
+            return ErrorResult.fatal(message: "Error handler failure: \(error.localizedDescription)")
+        }
+    }
+    
+    // MARK: - Error Categorization
+    
+    /**
+     * Categorize error by type, code, and severity
+     * 
+     * @param error Error to categorize
+     * @return ErrorInfo with categorization
+     */
+    private func categorizeError(_ error: Error) -> ErrorInfo {
+        do {
+            let category = determineCategory(error)
+            let errorCode = determineErrorCode(error)
+            let severity = determineSeverity(error, category: category)
+            
+            let errorInfo = ErrorInfo(
+                error: error,
+                category: category,
+                errorCode: errorCode,
+                severity: severity,
+                timestamp: Date()
+            )
+            
+            logger.debug(DailyNotificationErrorHandler.TAG, "Error categorized: \(errorInfo)")
+            return errorInfo
+            
+        } catch {
+            logger.error(DailyNotificationErrorHandler.TAG, "Error during categorization: \(error)")
+            return ErrorInfo(
+                error: error,
+                category: .unknown,
+                errorCode: "CATEGORIZATION_FAILED",
+                severity: .high,
+                timestamp: Date()
+            )
+        }
+    }
+    
+    /**
+     * Determine error category based on error type
+     * 
+     * @param error Error to analyze
+     * @return ErrorCategory
+     */
+    private func determineCategory(_ error: Error) -> ErrorCategory {
+        let errorType = String(describing: type(of: error))
+        let errorMessage = error.localizedDescription
+        
+        // Network errors
+        if errorType.contains("URLError") || errorType.contains("Network") || 
+           errorType.contains("Connection") || errorType.contains("Timeout") {
+            return .network
+        }
+        
+        // Storage errors
+        if errorType.contains("SQLite") || errorType.contains("Database") || 
+           errorType.contains("Storage") || errorType.contains("File") {
+            return .storage
+        }
+        
+        // Permission errors
+        if errorType.contains("Security") || errorType.contains("Permission") || 
+           errorMessage.contains("permission") {
+            return .permission
+        }
+        
+        // Configuration errors
+        if errorType.contains("IllegalArgument") || errorType.contains("Configuration") || 
+           errorMessage.contains("config") {
+            return .configuration
+        }
+        
+        // System errors
+        if errorType.contains("OutOfMemory") || errorType.contains("StackOverflow") || 
+           errorType.contains("Runtime") {
+            return .system
+        }
+        
+        return .unknown
+    }
+    
+    /**
+     * Determine error code based on error details
+     * 
+     * @param error Error to analyze
+     * @return Error code string
+     */
+    private func determineErrorCode(_ error: Error) -> String {
+        let errorType = String(describing: type(of: error))
+        let errorMessage = error.localizedDescription
+        
+        // Generate error code based on type and message
+        if !errorMessage.isEmpty {
+            return "\(errorType)_\(errorMessage.hashValue)"
+        } else {
+            return "\(errorType)_\(Date().timeIntervalSince1970)"
+        }
+    }
+    
+    /**
+     * Determine error severity based on error and category
+     * 
+     * @param error Error to analyze
+     * @param category Error category
+     * @return ErrorSeverity
+     */
+    private func determineSeverity(_ error: Error, category: ErrorCategory) -> ErrorSeverity {
+        let errorType = String(describing: type(of: error))
+        
+        // Critical errors
+        if errorType.contains("OutOfMemory") || errorType.contains("StackOverflow") {
+            return .critical
+        }
+        
+        // High severity errors
+        if category == .system || category == .storage {
+            return .high
+        }
+        
+        // Medium severity errors
+        if category == .network || category == .permission {
+            return .medium
+        }
+        
+        // Low severity errors
+        return .low
+    }
+    
+    // MARK: - Retry Logic
+    
+    /**
+     * Check if error should be retried
+     * 
+     * @param operationId Operation identifier
+     * @param errorInfo Error information
+     * @return true if should retry
+     */
+    private func shouldRetry(operationId: String, errorInfo: ErrorInfo) -> Bool {
+        return shouldRetry(operationId: operationId, errorInfo: errorInfo, retryConfig: nil)
+    }
+    
+    /**
+     * Check if error should be retried with custom config
+     * 
+     * @param operationId Operation identifier
+     * @param errorInfo Error information
+     * @param retryConfig Custom retry configuration
+     * @return true if should retry
+     */
+    private func shouldRetry(operationId: String, errorInfo: ErrorInfo, retryConfig: RetryConfiguration?) -> Bool {
+        do {
+            // Get retry state
+            var state: RetryState
+            retryQueue.sync {
+                if retryStates[operationId] == nil {
+                    retryStates[operationId] = RetryState()
+                }
+                state = retryStates[operationId]!
+            }
+            
+            // Check retry limits
+            let maxRetries = retryConfig?.maxRetries ?? config.maxRetries
+            if state.attemptCount >= maxRetries {
+                logger.debug(DailyNotificationErrorHandler.TAG, "Max retries exceeded for operation: \(operationId)")
+                return false
+            }
+            
+            // Check if error is retryable based on category
+            let isRetryable = isErrorRetryable(errorInfo.category)
+            
+            logger.debug(DailyNotificationErrorHandler.TAG, "Should retry: \(isRetryable) (attempt: \(state.attemptCount)/\(maxRetries))")
+            return isRetryable
+            
+        } catch {
+            logger.error(DailyNotificationErrorHandler.TAG, "Error checking retry eligibility: \(error)")
+            return false
+        }
+    }
+    
+    /**
+     * Check if error category is retryable
+     * 
+     * @param category Error category
+     * @return true if retryable
+     */
+    private func isErrorRetryable(_ category: ErrorCategory) -> Bool {
+        switch category {
+        case .network, .storage:
+            return true
+        case .permission, .configuration, .system, .unknown:
+            return false
+        }
+    }
+    
+    /**
+     * Handle retryable error
+     * 
+     * @param operationId Operation identifier
+     * @param errorInfo Error information
+     * @return ErrorResult with retry information
+     */
+    private func handleRetryableError(operationId: String, errorInfo: ErrorInfo) -> ErrorResult {
+        return handleRetryableError(operationId: operationId, errorInfo: errorInfo, retryConfig: nil)
+    }
+    
+    /**
+     * Handle retryable error with custom config
+     * 
+     * @param operationId Operation identifier
+     * @param errorInfo Error information
+     * @param retryConfig Custom retry configuration
+     * @return ErrorResult with retry information
+     */
+    private func handleRetryableError(operationId: String, errorInfo: ErrorInfo, retryConfig: RetryConfiguration?) -> ErrorResult {
+        do {
+            var state: RetryState
+            retryQueue.sync {
+                state = retryStates[operationId]!
+                state.attemptCount += 1
+            }
+            
+            // Calculate delay with exponential backoff
+            let delay = calculateRetryDelay(attemptCount: state.attemptCount, retryConfig: retryConfig)
+            state.nextRetryTime = Date().addingTimeInterval(delay)
+            
+            logger.info(DailyNotificationErrorHandler.TAG, "Retryable error handled - retry in \(delay)s (attempt \(state.attemptCount))")
+            
+            return ErrorResult.retryable(errorInfo: errorInfo, retryDelaySeconds: delay, attemptCount: state.attemptCount)
+            
+        } catch {
+            logger.error(DailyNotificationErrorHandler.TAG, "Error handling retryable error: \(error)")
+            return ErrorResult.fatal(message: "Retry handling failure: \(error.localizedDescription)")
+        }
+    }
+    
+    /**
+     * Handle non-retryable error
+     * 
+     * @param operationId Operation identifier
+     * @param errorInfo Error information
+     * @return ErrorResult with failure information
+     */
+    private func handleNonRetryableError(operationId: String, errorInfo: ErrorInfo) -> ErrorResult {
+        do {
+            logger.warning(DailyNotificationErrorHandler.TAG, "Non-retryable error handled for operation: \(operationId)")
+            
+            // Clean up retry state
+            retryQueue.async(flags: .barrier) {
+                self.retryStates.removeValue(forKey: operationId)
+            }
+            
+            return ErrorResult.fatal(errorInfo: errorInfo)
+            
+        } catch {
+            logger.error(DailyNotificationErrorHandler.TAG, "Error handling non-retryable error: \(error)")
+            return ErrorResult.fatal(message: "Non-retryable error handling failure: \(error.localizedDescription)")
+        }
+    }
+    
+    /**
+     * Calculate retry delay with exponential backoff
+     * 
+     * @param attemptCount Current attempt number
+     * @param retryConfig Custom retry configuration
+     * @return Delay in seconds
+     */
+    private func calculateRetryDelay(attemptCount: Int, retryConfig: RetryConfiguration?) -> TimeInterval {
+        do {
+            let baseDelay = retryConfig?.baseDelaySeconds ?? config.baseDelaySeconds
+            let multiplier = retryConfig?.backoffMultiplier ?? config.backoffMultiplier
+            let maxDelay = retryConfig?.maxDelaySeconds ?? config.maxDelaySeconds
+            
+            // Calculate exponential backoff: baseDelay * (multiplier ^ (attemptCount - 1))
+            var delay = baseDelay * pow(multiplier, Double(attemptCount - 1))
+            
+            // Cap at maximum delay
+            delay = min(delay, maxDelay)
+            
+            // Add jitter to prevent thundering herd
+            let jitter = delay * 0.1 * Double.random(in: 0...1)
+            delay += jitter
+            
+            logger.debug(DailyNotificationErrorHandler.TAG, "Calculated retry delay: \(delay)s (attempt \(attemptCount))")
+            return delay
+            
+        } catch {
+            logger.error(DailyNotificationErrorHandler.TAG, "Error calculating retry delay: \(error)")
+            return config.baseDelaySeconds
+        }
+    }
+    
+    // MARK: - Metrics and Telemetry
+    
+    /**
+     * Get error metrics
+     * 
+     * @return ErrorMetrics with current statistics
+     */
+    func getMetrics() -> ErrorMetrics {
+        return metrics
+    }
+    
+    /**
+     * Reset error metrics
+     */
+    func resetMetrics() {
+        metrics.reset()
+        logger.debug(DailyNotificationErrorHandler.TAG, "Error metrics reset")
+    }
+    
+    /**
+     * Get retry statistics
+     * 
+     * @return RetryStatistics with retry information
+     */
+    func getRetryStatistics() -> RetryStatistics {
+        var totalOperations = 0
+        var activeRetries = 0
+        var totalRetries = 0
+        
+        retryQueue.sync {
+            totalOperations = retryStates.count
+            for state in retryStates.values {
+                if state.attemptCount > 0 {
+                    activeRetries += 1
+                    totalRetries += state.attemptCount
+                }
+            }
+        }
+        
+        return RetryStatistics(totalOperations: totalOperations, activeRetries: activeRetries, totalRetries: totalRetries)
+    }
+    
+    /**
+     * Clear retry states
+     */
+    func clearRetryStates() {
+        retryQueue.async(flags: .barrier) {
+            self.retryStates.removeAll()
+        }
+        logger.debug(DailyNotificationErrorHandler.TAG, "Retry states cleared")
+    }
+    
+    // MARK: - Data Classes
+    
+    /**
+     * Error information
+     */
+    struct ErrorInfo {
+        let error: Error
+        let category: ErrorCategory
+        let errorCode: String
+        let severity: ErrorSeverity
+        let timestamp: Date
+        
+        var description: String {
+            return "ErrorInfo{category=\(category), code=\(errorCode), severity=\(severity), error=\(String(describing: type(of: error)))}"
+        }
+    }
+    
+    /**
+     * Retry state for an operation
+     */
+    private class RetryState {
+        var attemptCount = 0
+        var nextRetryTime = Date()
+    }
+    
+    /**
+     * Error result
+     */
+    struct ErrorResult {
+        let success: Bool
+        let retryable: Bool
+        let errorInfo: ErrorInfo?
+        let retryDelaySeconds: TimeInterval
+        let attemptCount: Int
+        let message: String
+        
+        static func retryable(errorInfo: ErrorInfo, retryDelaySeconds: TimeInterval, attemptCount: Int) -> ErrorResult {
+            return ErrorResult(success: false, retryable: true, errorInfo: errorInfo, retryDelaySeconds: retryDelaySeconds, attemptCount: attemptCount, message: "Retryable error")
+        }
+        
+        static func fatal(errorInfo: ErrorInfo) -> ErrorResult {
+            return ErrorResult(success: false, retryable: false, errorInfo: errorInfo, retryDelaySeconds: 0, attemptCount: 0, message: "Fatal error")
+        }
+        
+        static func fatal(message: String) -> ErrorResult {
+            return ErrorResult(success: false, retryable: false, errorInfo: nil, retryDelaySeconds: 0, attemptCount: 0, message: message)
+        }
+    }
+    
+    /**
+     * Error configuration
+     */
+    struct ErrorConfiguration {
+        let maxRetries: Int
+        let baseDelaySeconds: TimeInterval
+        let maxDelaySeconds: TimeInterval
+        let backoffMultiplier: Double
+        
+        init() {
+            self.maxRetries = DailyNotificationErrorHandler.DEFAULT_MAX_RETRIES
+            self.baseDelaySeconds = DailyNotificationErrorHandler.DEFAULT_BASE_DELAY_SECONDS
+            self.maxDelaySeconds = DailyNotificationErrorHandler.DEFAULT_MAX_DELAY_SECONDS
+            self.backoffMultiplier = DailyNotificationErrorHandler.DEFAULT_BACKOFF_MULTIPLIER
+        }
+        
+        init(maxRetries: Int, baseDelaySeconds: TimeInterval, maxDelaySeconds: TimeInterval, backoffMultiplier: Double) {
+            self.maxRetries = maxRetries
+            self.baseDelaySeconds = baseDelaySeconds
+            self.maxDelaySeconds = maxDelaySeconds
+            self.backoffMultiplier = backoffMultiplier
+        }
+    }
+    
+    /**
+     * Retry configuration
+     */
+    struct RetryConfiguration {
+        let maxRetries: Int
+        let baseDelaySeconds: TimeInterval
+        let maxDelaySeconds: TimeInterval
+        let backoffMultiplier: Double
+        
+        init(maxRetries: Int, baseDelaySeconds: TimeInterval, maxDelaySeconds: TimeInterval, backoffMultiplier: Double) {
+            self.maxRetries = maxRetries
+            self.baseDelaySeconds = baseDelaySeconds
+            self.maxDelaySeconds = maxDelaySeconds
+            self.backoffMultiplier = backoffMultiplier
+        }
+    }
+    
+    /**
+     * Error metrics
+     */
+    class ErrorMetrics {
+        private var totalErrors = 0
+        private var networkErrors = 0
+        private var storageErrors = 0
+        private var schedulingErrors = 0
+        private var permissionErrors = 0
+        private var configurationErrors = 0
+        private var systemErrors = 0
+        private var unknownErrors = 0
+        
+        func recordError(_ errorInfo: ErrorInfo) {
+            totalErrors += 1
+            
+            switch errorInfo.category {
+            case .network:
+                networkErrors += 1
+            case .storage:
+                storageErrors += 1
+            case .scheduling:
+                schedulingErrors += 1
+            case .permission:
+                permissionErrors += 1
+            case .configuration:
+                configurationErrors += 1
+            case .system:
+                systemErrors += 1
+            case .unknown:
+                unknownErrors += 1
+            }
+        }
+        
+        func reset() {
+            totalErrors = 0
+            networkErrors = 0
+            storageErrors = 0
+            schedulingErrors = 0
+            permissionErrors = 0
+            configurationErrors = 0
+            systemErrors = 0
+            unknownErrors = 0
+        }
+        
+        var totalErrorsCount: Int { return totalErrors }
+        var networkErrorsCount: Int { return networkErrors }
+        var storageErrorsCount: Int { return storageErrors }
+        var schedulingErrorsCount: Int { return schedulingErrors }
+        var permissionErrorsCount: Int { return permissionErrors }
+        var configurationErrorsCount: Int { return configurationErrors }
+        var systemErrorsCount: Int { return systemErrors }
+        var unknownErrorsCount: Int { return unknownErrors }
+    }
+    
+    /**
+     * Retry statistics
+     */
+    struct RetryStatistics {
+        let totalOperations: Int
+        let activeRetries: Int
+        let totalRetries: Int
+        
+        var description: String {
+            return "RetryStatistics{totalOps=\(totalOperations), activeRetries=\(activeRetries), totalRetries=\(totalRetries)}"
+        }
+    }
+}
--- a/src/android/DailyNotificationErrorHandler.java
+++ b/src/android/DailyNotificationErrorHandler.java
@ -0,0 +1,668 @@
+/**
+ * DailyNotificationErrorHandler.java
+ * 
+ * Android Error Handler for comprehensive error management
+ * Implements error categorization, retry logic, and telemetry
+ * 
+ * @author Matthew Raymer
+ * @version 1.0.0
+ */
+
+package com.timesafari.dailynotification;
+
+import android.util.Log;
+
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Manages comprehensive error handling with categorization, retry logic, and telemetry
+ * 
+ * This class implements the critical error handling functionality:
+ * - Categorizes errors by type, code, and severity
+ * - Implements exponential backoff retry logic
+ * - Tracks error metrics and telemetry
+ * - Provides debugging information
+ * - Manages retry state and limits
+ */
+public class DailyNotificationErrorHandler {
+    
+    // MARK: - Constants
+    
+    private static final String TAG = "DailyNotificationErrorHandler";
+    
+    // Retry configuration
+    private static final int DEFAULT_MAX_RETRIES = 3;
+    private static final long DEFAULT_BASE_DELAY_MS = 1000; // 1 second
+    private static final long DEFAULT_MAX_DELAY_MS = 30000; // 30 seconds
+    private static final double DEFAULT_BACKOFF_MULTIPLIER = 2.0;
+    
+    // Error severity levels
+    public enum ErrorSeverity {
+        LOW,        // Minor issues, non-critical
+        MEDIUM,     // Moderate issues, may affect functionality
+        HIGH,       // Serious issues, significant impact
+        CRITICAL    // Critical issues, system failure
+    }
+    
+    // Error categories
+    public enum ErrorCategory {
+        NETWORK,        // Network-related errors
+        STORAGE,        // Storage/database errors
+        SCHEDULING,     // Notification scheduling errors
+        PERMISSION,     // Permission-related errors
+        CONFIGURATION,  // Configuration errors
+        SYSTEM,         // System-level errors
+        UNKNOWN         // Unknown/unclassified errors
+    }
+    
+    // MARK: - Properties
+    
+    private final ConcurrentHashMap<String, RetryState> retryStates;
+    private final ErrorMetrics metrics;
+    private final ErrorConfiguration config;
+    
+    // MARK: - Initialization
+    
+    /**
+     * Constructor with default configuration
+     */
+    public DailyNotificationErrorHandler() {
+        this(new ErrorConfiguration());
+    }
+    
+    /**
+     * Constructor with custom configuration
+     * 
+     * @param config Error handling configuration
+     */
+    public DailyNotificationErrorHandler(ErrorConfiguration config) {
+        this.retryStates = new ConcurrentHashMap<>();
+        this.metrics = new ErrorMetrics();
+        this.config = config;
+        
+        Log.d(TAG, "ErrorHandler initialized with max retries: " + config.maxRetries);
+    }
+    
+    // MARK: - Error Handling
+    
+    /**
+     * Handle error with automatic retry logic
+     * 
+     * @param operationId Unique identifier for the operation
+     * @param error Error to handle
+     * @param retryable Whether this error is retryable
+     * @return ErrorResult with handling information
+     */
+    public ErrorResult handleError(String operationId, Throwable error, boolean retryable) {
+        try {
+            Log.d(TAG, "Handling error for operation: " + operationId);
+            
+            // Categorize error
+            ErrorInfo errorInfo = categorizeError(error);
+            
+            // Update metrics
+            metrics.recordError(errorInfo);
+            
+            // Check if retryable and within limits
+            if (retryable && shouldRetry(operationId, errorInfo)) {
+                return handleRetryableError(operationId, errorInfo);
+            } else {
+                return handleNonRetryableError(operationId, errorInfo);
+            }
+            
+        } catch (Exception e) {
+            Log.e(TAG, "Error in error handler", e);
+            return ErrorResult.fatal("Error handler failure: " + e.getMessage());
+        }
+    }
+    
+    /**
+     * Handle error with custom retry configuration
+     * 
+     * @param operationId Unique identifier for the operation
+     * @param error Error to handle
+     * @param retryConfig Custom retry configuration
+     * @return ErrorResult with handling information
+     */
+    public ErrorResult handleError(String operationId, Throwable error, RetryConfiguration retryConfig) {
+        try {
+            Log.d(TAG, "Handling error with custom retry config for operation: " + operationId);
+            
+            // Categorize error
+            ErrorInfo errorInfo = categorizeError(error);
+            
+            // Update metrics
+            metrics.recordError(errorInfo);
+            
+            // Check if retryable with custom config
+            if (shouldRetry(operationId, errorInfo, retryConfig)) {
+                return handleRetryableError(operationId, errorInfo, retryConfig);
+            } else {
+                return handleNonRetryableError(operationId, errorInfo);
+            }
+            
+        } catch (Exception e) {
+            Log.e(TAG, "Error in error handler with custom config", e);
+            return ErrorResult.fatal("Error handler failure: " + e.getMessage());
+        }
+    }
+    
+    // MARK: - Error Categorization
+    
+    /**
+     * Categorize error by type, code, and severity
+     * 
+     * @param error Error to categorize
+     * @return ErrorInfo with categorization
+     */
+    private ErrorInfo categorizeError(Throwable error) {
+        try {
+            ErrorCategory category = determineCategory(error);
+            String errorCode = determineErrorCode(error);
+            ErrorSeverity severity = determineSeverity(error, category);
+            
+            ErrorInfo errorInfo = new ErrorInfo(
+                error,
+                category,
+                errorCode,
+                severity,
+                System.currentTimeMillis()
+            );
+            
+            Log.d(TAG, "Error categorized: " + errorInfo);
+            return errorInfo;
+            
+        } catch (Exception e) {
+            Log.e(TAG, "Error during categorization", e);
+            return new ErrorInfo(error, ErrorCategory.UNKNOWN, "CATEGORIZATION_FAILED", ErrorSeverity.HIGH, System.currentTimeMillis());
+        }
+    }
+    
+    /**
+     * Determine error category based on error type
+     * 
+     * @param error Error to analyze
+     * @return ErrorCategory
+     */
+    private ErrorCategory determineCategory(Throwable error) {
+        String errorMessage = error.getMessage();
+        String errorType = error.getClass().getSimpleName();
+        
+        // Network errors
+        if (errorType.contains("IOException") || errorType.contains("Socket") || 
+            errorType.contains("Connect") || errorType.contains("Timeout")) {
+            return ErrorCategory.NETWORK;
+        }
+        
+        // Storage errors
+        if (errorType.contains("SQLite") || errorType.contains("Database") || 
+            errorType.contains("Storage") || errorType.contains("File")) {
+            return ErrorCategory.STORAGE;
+        }
+        
+        // Permission errors
+        if (errorType.contains("Security") || errorType.contains("Permission") || 
+            errorMessage != null && errorMessage.contains("permission")) {
+            return ErrorCategory.PERMISSION;
+        }
+        
+        // Configuration errors
+        if (errorType.contains("IllegalArgument") || errorType.contains("Configuration") || 
+            errorMessage != null && errorMessage.contains("config")) {
+            return ErrorCategory.CONFIGURATION;
+        }
+        
+        // System errors
+        if (errorType.contains("OutOfMemory") || errorType.contains("StackOverflow") || 
+            errorType.contains("Runtime")) {
+            return ErrorCategory.SYSTEM;
+        }
+        
+        return ErrorCategory.UNKNOWN;
+    }
+    
+    /**
+     * Determine error code based on error details
+     * 
+     * @param error Error to analyze
+     * @return Error code string
+     */
+    private String determineErrorCode(Throwable error) {
+        String errorType = error.getClass().getSimpleName();
+        String errorMessage = error.getMessage();
+        
+        // Generate error code based on type and message
+        if (errorMessage != null && errorMessage.length() > 0) {
+            return errorType + "_" + errorMessage.hashCode();
+        } else {
+            return errorType + "_" + System.currentTimeMillis();
+        }
+    }
+    
+    /**
+     * Determine error severity based on error and category
+     * 
+     * @param error Error to analyze
+     * @param category Error category
+     * @return ErrorSeverity
+     */
+    private ErrorSeverity determineSeverity(Throwable error, ErrorCategory category) {
+        // Critical errors
+        if (error instanceof OutOfMemoryError || error instanceof StackOverflowError) {
+            return ErrorSeverity.CRITICAL;
+        }
+        
+        // High severity errors
+        if (category == ErrorCategory.SYSTEM || category == ErrorCategory.STORAGE) {
+            return ErrorSeverity.HIGH;
+        }
+        
+        // Medium severity errors
+        if (category == ErrorCategory.NETWORK || category == ErrorCategory.PERMISSION) {
+            return ErrorSeverity.MEDIUM;
+        }
+        
+        // Low severity errors
+        return ErrorSeverity.LOW;
+    }
+    
+    // MARK: - Retry Logic
+    
+    /**
+     * Check if error should be retried
+     * 
+     * @param operationId Operation identifier
+     * @param errorInfo Error information
+     * @return true if should retry
+     */
+    private boolean shouldRetry(String operationId, ErrorInfo errorInfo) {
+        return shouldRetry(operationId, errorInfo, null);
+    }
+    
+    /**
+     * Check if error should be retried with custom config
+     * 
+     * @param operationId Operation identifier
+     * @param errorInfo Error information
+     * @param retryConfig Custom retry configuration
+     * @return true if should retry
+     */
+    private boolean shouldRetry(String operationId, ErrorInfo errorInfo, RetryConfiguration retryConfig) {
+        try {
+            // Get retry state
+            RetryState state = retryStates.get(operationId);
+            if (state == null) {
+                state = new RetryState();
+                retryStates.put(operationId, state);
+            }
+            
+            // Check retry limits
+            int maxRetries = retryConfig != null ? retryConfig.maxRetries : config.maxRetries;
+            if (state.attemptCount >= maxRetries) {
+                Log.d(TAG, "Max retries exceeded for operation: " + operationId);
+                return false;
+            }
+            
+            // Check if error is retryable based on category
+            boolean isRetryable = isErrorRetryable(errorInfo.category);
+            
+            Log.d(TAG, "Should retry: " + isRetryable + " (attempt: " + state.attemptCount + "/" + maxRetries + ")");
+            return isRetryable;
+            
+        } catch (Exception e) {
+            Log.e(TAG, "Error checking retry eligibility", e);
+            return false;
+        }
+    }
+    
+    /**
+     * Check if error category is retryable
+     * 
+     * @param category Error category
+     * @return true if retryable
+     */
+    private boolean isErrorRetryable(ErrorCategory category) {
+        switch (category) {
+            case NETWORK:
+            case STORAGE:
+                return true;
+            case PERMISSION:
+            case CONFIGURATION:
+            case SYSTEM:
+            case UNKNOWN:
+            default:
+                return false;
+        }
+    }
+    
+    /**
+     * Handle retryable error
+     * 
+     * @param operationId Operation identifier
+     * @param errorInfo Error information
+     * @return ErrorResult with retry information
+     */
+    private ErrorResult handleRetryableError(String operationId, ErrorInfo errorInfo) {
+        return handleRetryableError(operationId, errorInfo, null);
+    }
+    
+    /**
+     * Handle retryable error with custom config
+     * 
+     * @param operationId Operation identifier
+     * @param errorInfo Error information
+     * @param retryConfig Custom retry configuration
+     * @return ErrorResult with retry information
+     */
+    private ErrorResult handleRetryableError(String operationId, ErrorInfo errorInfo, RetryConfiguration retryConfig) {
+        try {
+            RetryState state = retryStates.get(operationId);
+            state.attemptCount++;
+            
+            // Calculate delay with exponential backoff
+            long delay = calculateRetryDelay(state.attemptCount, retryConfig);
+            state.nextRetryTime = System.currentTimeMillis() + delay;
+            
+            Log.i(TAG, "Retryable error handled - retry in " + delay + "ms (attempt " + state.attemptCount + ")");
+            
+            return ErrorResult.retryable(errorInfo, delay, state.attemptCount);
+            
+        } catch (Exception e) {
+            Log.e(TAG, "Error handling retryable error", e);
+            return ErrorResult.fatal("Retry handling failure: " + e.getMessage());
+        }
+    }
+    
+    /**
+     * Handle non-retryable error
+     * 
+     * @param operationId Operation identifier
+     * @param errorInfo Error information
+     * @return ErrorResult with failure information
+     */
+    private ErrorResult handleNonRetryableError(String operationId, ErrorInfo errorInfo) {
+        try {
+            Log.w(TAG, "Non-retryable error handled for operation: " + operationId);
+            
+            // Clean up retry state
+            retryStates.remove(operationId);
+            
+            return ErrorResult.fatal(errorInfo);
+            
+        } catch (Exception e) {
+            Log.e(TAG, "Error handling non-retryable error", e);
+            return ErrorResult.fatal("Non-retryable error handling failure: " + e.getMessage());
+        }
+    }
+    
+    /**
+     * Calculate retry delay with exponential backoff
+     * 
+     * @param attemptCount Current attempt number
+     * @param retryConfig Custom retry configuration
+     * @return Delay in milliseconds
+     */
+    private long calculateRetryDelay(int attemptCount, RetryConfiguration retryConfig) {
+        try {
+            long baseDelay = retryConfig != null ? retryConfig.baseDelayMs : config.baseDelayMs;
+            double multiplier = retryConfig != null ? retryConfig.backoffMultiplier : config.backoffMultiplier;
+            long maxDelay = retryConfig != null ? retryConfig.maxDelayMs : config.maxDelayMs;
+            
+            // Calculate exponential backoff: baseDelay * (multiplier ^ (attemptCount - 1))
+            long delay = (long) (baseDelay * Math.pow(multiplier, attemptCount - 1));
+            
+            // Cap at maximum delay
+            delay = Math.min(delay, maxDelay);
+            
+            // Add jitter to prevent thundering herd
+            long jitter = (long) (delay * 0.1 * Math.random());
+            delay += jitter;
+            
+            Log.d(TAG, "Calculated retry delay: " + delay + "ms (attempt " + attemptCount + ")");
+            return delay;
+            
+        } catch (Exception e) {
+            Log.e(TAG, "Error calculating retry delay", e);
+            return config.baseDelayMs;
+        }
+    }
+    
+    // MARK: - Metrics and Telemetry
+    
+    /**
+     * Get error metrics
+     * 
+     * @return ErrorMetrics with current statistics
+     */
+    public ErrorMetrics getMetrics() {
+        return metrics;
+    }
+    
+    /**
+     * Reset error metrics
+     */
+    public void resetMetrics() {
+        metrics.reset();
+        Log.d(TAG, "Error metrics reset");
+    }
+    
+    /**
+     * Get retry statistics
+     * 
+     * @return RetryStatistics with retry information
+     */
+    public RetryStatistics getRetryStatistics() {
+        int totalOperations = retryStates.size();
+        int activeRetries = 0;
+        int totalRetries = 0;
+        
+        for (RetryState state : retryStates.values()) {
+            if (state.attemptCount > 0) {
+                activeRetries++;
+                totalRetries += state.attemptCount;
+            }
+        }
+        
+        return new RetryStatistics(totalOperations, activeRetries, totalRetries);
+    }
+    
+    /**
+     * Clear retry states
+     */
+    public void clearRetryStates() {
+        retryStates.clear();
+        Log.d(TAG, "Retry states cleared");
+    }
+    
+    // MARK: - Data Classes
+    
+    /**
+     * Error information
+     */
+    public static class ErrorInfo {
+        public final Throwable error;
+        public final ErrorCategory category;
+        public final String errorCode;
+        public final ErrorSeverity severity;
+        public final long timestamp;
+        
+        public ErrorInfo(Throwable error, ErrorCategory category, String errorCode, ErrorSeverity severity, long timestamp) {
+            this.error = error;
+            this.category = category;
+            this.errorCode = errorCode;
+            this.severity = severity;
+            this.timestamp = timestamp;
+        }
+        
+        @Override
+        public String toString() {
+            return String.format("ErrorInfo{category=%s, code=%s, severity=%s, error=%s}", 
+                category, errorCode, severity, error.getClass().getSimpleName());
+        }
+    }
+    
+    /**
+     * Retry state for an operation
+     */
+    private static class RetryState {
+        public int attemptCount = 0;
+        public long nextRetryTime = 0;
+    }
+    
+    /**
+     * Error result
+     */
+    public static class ErrorResult {
+        public final boolean success;
+        public final boolean retryable;
+        public final ErrorInfo errorInfo;
+        public final long retryDelayMs;
+        public final int attemptCount;
+        public final String message;
+        
+        private ErrorResult(boolean success, boolean retryable, ErrorInfo errorInfo, long retryDelayMs, int attemptCount, String message) {
+            this.success = success;
+            this.retryable = retryable;
+            this.errorInfo = errorInfo;
+            this.retryDelayMs = retryDelayMs;
+            this.attemptCount = attemptCount;
+            this.message = message;
+        }
+        
+        public static ErrorResult retryable(ErrorInfo errorInfo, long retryDelayMs, int attemptCount) {
+            return new ErrorResult(false, true, errorInfo, retryDelayMs, attemptCount, "Retryable error");
+        }
+        
+        public static ErrorResult fatal(ErrorInfo errorInfo) {
+            return new ErrorResult(false, false, errorInfo, 0, 0, "Fatal error");
+        }
+        
+        public static ErrorResult fatal(String message) {
+            return new ErrorResult(false, false, null, 0, 0, message);
+        }
+    }
+    
+    /**
+     * Error configuration
+     */
+    public static class ErrorConfiguration {
+        public final int maxRetries;
+        public final long baseDelayMs;
+        public final long maxDelayMs;
+        public final double backoffMultiplier;
+        
+        public ErrorConfiguration() {
+            this(DEFAULT_MAX_RETRIES, DEFAULT_BASE_DELAY_MS, DEFAULT_MAX_DELAY_MS, DEFAULT_BACKOFF_MULTIPLIER);
+        }
+        
+        public ErrorConfiguration(int maxRetries, long baseDelayMs, long maxDelayMs, double backoffMultiplier) {
+            this.maxRetries = maxRetries;
+            this.baseDelayMs = baseDelayMs;
+            this.maxDelayMs = maxDelayMs;
+            this.backoffMultiplier = backoffMultiplier;
+        }
+    }
+    
+    /**
+     * Retry configuration
+     */
+    public static class RetryConfiguration {
+        public final int maxRetries;
+        public final long baseDelayMs;
+        public final long maxDelayMs;
+        public final double backoffMultiplier;
+        
+        public RetryConfiguration(int maxRetries, long baseDelayMs, long maxDelayMs, double backoffMultiplier) {
+            this.maxRetries = maxRetries;
+            this.baseDelayMs = baseDelayMs;
+            this.maxDelayMs = maxDelayMs;
+            this.backoffMultiplier = backoffMultiplier;
+        }
+    }
+    
+    /**
+     * Error metrics
+     */
+    public static class ErrorMetrics {
+        private final AtomicInteger totalErrors = new AtomicInteger(0);
+        private final AtomicInteger networkErrors = new AtomicInteger(0);
+        private final AtomicInteger storageErrors = new AtomicInteger(0);
+        private final AtomicInteger schedulingErrors = new AtomicInteger(0);
+        private final AtomicInteger permissionErrors = new AtomicInteger(0);
+        private final AtomicInteger configurationErrors = new AtomicInteger(0);
+        private final AtomicInteger systemErrors = new AtomicInteger(0);
+        private final AtomicInteger unknownErrors = new AtomicInteger(0);
+        
+        public void recordError(ErrorInfo errorInfo) {
+            totalErrors.incrementAndGet();
+            
+            switch (errorInfo.category) {
+                case NETWORK:
+                    networkErrors.incrementAndGet();
+                    break;
+                case STORAGE:
+                    storageErrors.incrementAndGet();
+                    break;
+                case SCHEDULING:
+                    schedulingErrors.incrementAndGet();
+                    break;
+                case PERMISSION:
+                    permissionErrors.incrementAndGet();
+                    break;
+                case CONFIGURATION:
+                    configurationErrors.incrementAndGet();
+                    break;
+                case SYSTEM:
+                    systemErrors.incrementAndGet();
+                    break;
+                case UNKNOWN:
+                default:
+                    unknownErrors.incrementAndGet();
+                    break;
+            }
+        }
+        
+        public void reset() {
+            totalErrors.set(0);
+            networkErrors.set(0);
+            storageErrors.set(0);
+            schedulingErrors.set(0);
+            permissionErrors.set(0);
+            configurationErrors.set(0);
+            systemErrors.set(0);
+            unknownErrors.set(0);
+        }
+        
+        public int getTotalErrors() { return totalErrors.get(); }
+        public int getNetworkErrors() { return networkErrors.get(); }
+        public int getStorageErrors() { return storageErrors.get(); }
+        public int getSchedulingErrors() { return schedulingErrors.get(); }
+        public int getPermissionErrors() { return permissionErrors.get(); }
+        public int getConfigurationErrors() { return configurationErrors.get(); }
+        public int getSystemErrors() { return systemErrors.get(); }
+        public int getUnknownErrors() { return unknownErrors.get(); }
+    }
+    
+    /**
+     * Retry statistics
+     */
+    public static class RetryStatistics {
+        public final int totalOperations;
+        public final int activeRetries;
+        public final int totalRetries;
+        
+        public RetryStatistics(int totalOperations, int activeRetries, int totalRetries) {
+            this.totalOperations = totalOperations;
+            this.activeRetries = activeRetries;
+            this.totalRetries = totalRetries;
+        }
+        
+        @Override
+        public String toString() {
+            return String.format("RetryStatistics{totalOps=%d, activeRetries=%d, totalRetries=%d}", 
+                totalOperations, activeRetries, totalRetries);
+        }
+    }
+}