const handleClientError = (error) => {
  switch (error.code) {
    case 'MISSING_API_KEY':
    case 'INVALID_API_KEY':
    case 'REVOKED_API_KEY':
      // Configuration issue - alert admin immediately
      alertAdmin('API Key Issue', error);
      break;
      
    case 'NO_ACTIVE_SUBSCRIPTION':
      // Show subscription modal
      showSubscriptionModal();
      break;
      
    case 'LIMIT_EXCEEDED':
      // Show upgrade prompt
      showUpgradePrompt();
      break;
      
    case 'DUPLICATE_SUBJECT_REFERENCE':
      // Use existing verification
      return handleDuplicateVerification(error.data.existingVerificationId);
      
    default:
      logError('Client Error', error);
  }
};

const handleServerError = async (request, attempt = 0) => {
  const maxRetries = 3;
  const baseDelay = 1000;
  
  try {
    return await makeRequest(request);
  } catch (error) {
    if (attempt >= maxRetries) {
      throw error;
    }
    
    const delay = baseDelay * Math.pow(2, attempt);
    await sleep(delay);
    
    return handleServerError(request, attempt + 1);
  }
};

const errorMessages = {
  NO_ACTIVE_SUBSCRIPTION: {
    title: 'Subscription Required',
    message: 'Please activate a subscription to create verifications.',
  },
  LIMIT_EXCEEDED: {
    title: 'Limit Reached',
    message: 'You have reached your monthly verification limit.',
  },
  DUPLICATE_SUBJECT_REFERENCE: {
    title: 'Verification Exists',
    message: 'A verification is already in progress for this user.',
  },
  VERIFICATION_NOT_FOUND: {
    title: 'Not Found',
    message: 'The requested verification could not be found.',
  },
  default: {
    title: 'Error',
    message: 'Something went wrong. Please try again later.',
  },
};

const logError = (error, context) => {
  const logEntry = {
    timestamp: new Date().toISOString(),
    code: error.code,
    message: error.message,
    endpoint: context.endpoint,
    method: context.method,
    // Never log API keys
  };
  
  logger.error('API Error', logEntry);
};