Error Handling

const maxRetries = 3;
let delay = 1000; // Start with 1 second

for (let attempt = 0; attempt < maxRetries; attempt++) {
  try {
    const response = await apiCall();
    return response;
  } catch (error) {
    if (isRetryableError(error) && attempt < maxRetries - 1) {
      await sleep(delay);
      delay *= 2; // Double the delay
    } else {
      throw error;
    }
  }
}

function isRetryableError(error) {
  const retryableCodes = [
    'SERVICE_UNAVAILABLE',
    'TIMEOUT',
    'INTERNAL_SERVER_ERROR',
    'RATE_LIMIT_EXCEEDED'
  ];
  return retryableCodes.includes(error.code);
}

function isUserError(error) {
  const userErrorTypes = ['validation', 'authentication'];
  return userErrorTypes.includes(error.type);
}

function getUserMessage(error) {
  const messageMap = {
    'NO_FLIGHTS_AVAILABLE': 'No flights found for your search. Try different dates or destinations.',
    'PAYMENT_DECLINED': 'Payment failed. Please check your card details or try a different payment method.',
    'BOOKING_NOT_FOUND': 'We couldn\'t find your booking. Please check your confirmation number.',
    'SERVICE_UNAVAILABLE': 'Service is temporarily unavailable. Please try again in a few minutes.'
  };
  
  return messageMap[error.code] || 'An unexpected error occurred. Please try again.';
}

function logError(error, context) {
  const logData = {
    timestamp: new Date().toISOString(),
    errorCode: error.code,
    errorMessage: error.message,
    requestId: error.requestId,
    userId: context.userId,
    endpoint: context.endpoint,
    requestData: context.requestData
  };
  
  // Send to logging service
  logger.error('OTA API Error', logData);
  
  // Send to monitoring service for alerts
  if (isCriticalError(error)) {
    monitoring.alert('Critical OTA API Error', logData);
  }
}

function validateSearchRequest(request) {
  const errors = [];
  
  if (!request.origin || !/^[A-Z]{3}$/.test(request.origin)) {
    errors.push('Origin must be a valid 3-letter airport code');
  }
  
  if (!request.departureDate || !isValidDate(request.departureDate)) {
    errors.push('Departure date must be a valid ISO 8601 date');
  }
  
  if (request.passengers < 1 || request.passengers > 9) {
    errors.push('Passenger count must be between 1 and 9');
  }
  
  return errors;
}

class RateLimiter {
  constructor(maxRequests, timeWindow) {
    this.maxRequests = maxRequests;
    this.timeWindow = timeWindow;
    this.requests = [];
  }
  
  canMakeRequest() {
    const now = Date.now();
    this.requests = this.requests.filter(
      time => now - time < this.timeWindow
    );
    
    if (this.requests.length >= this.maxRequests) {
      return false;
    }
    
    this.requests.push(now);
    return true;
  }
}