vwo-fme-node-sdk/lib/utils/UsageStatsUtil.ts

VWO Node/JavaScript SDK for Feature Management and Experimentation

/**
 * Copyright 2024-2025 Wingify Software Pvt. Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { LogLevelNumberEnum } from '../packages/logger/core/TransportManager';

/**
 * Manages usage statistics for the SDK.
 * Tracks various features and configurations being used by the client.
 * Implements Singleton pattern to ensure a single instance.
 */
export class UsageStatsUtil {
  /** Singleton instance */
  private static instance: UsageStatsUtil;

  /** Internal storage for usage statistics data */
  private usageStatsData: Record<string, string | number> = {};

  /** Private constructor to prevent direct instantiation */
  private constructor() {}

  /**
   * Provides access to the singleton instance of UsageStatsUtil.
   *
   * @returns The single instance of UsageStatsUtil
   */
  public static getInstance(): UsageStatsUtil {
    if (!UsageStatsUtil.instance) {
      UsageStatsUtil.instance = new UsageStatsUtil();
    }
    return UsageStatsUtil.instance;
  }

  /**
   * Sets usage statistics based on provided options.
   * Maps various SDK features and configurations to boolean flags.
   *
   * @param options - Configuration options for the SDK
   * @param options.storage - Storage service configuration
   * @param options.logger - Logger configuration
   * @param options.eventBatching - Event batching configuration
   * @param options.integrations - Integrations configuration
   * @param options.pollingInterval - Polling interval configuration
   * @param options.sdkName - SDK name configuration
   */
  setUsageStats(options: any): void {
    const {
      storage,
      logger,
      batchEvents,
      gatewayService,
      integrations,
      pollingInterval,
      _vwo_meta,
      shouldWaitForTrackingCalls,
    } = options;

    const data: Record<string, string | number> = {};

    // Map configuration options to usage stats flags
    if (integrations) data.ig = 1; // Integration enabled
    if (batchEvents) data.eb = 1; // Event batching enabled

    // if logger has transport or transports, then it is custom logger
    if (logger && (logger.transport || logger.transports)) data.cl = 1;

    if (storage) data.ss = 1; // Storage service configured
    if (logger?.level) {
      data.ll = LogLevelNumberEnum[logger.level.toUpperCase()] ?? -1; // Default to -1 if level is not recognized
    }

    if (gatewayService) data.gs = 1; // Gateway service configured

    if (pollingInterval) data.pi = 1; // Polling interval configured

    if (shouldWaitForTrackingCalls) data.swtc = 1;

    // if _vwo_meta has ea, then addd data._ea to be 1
    if (_vwo_meta && _vwo_meta.ea) data._ea = 1;

    // Check if sdk running in browser and not in edge/serverless environment
    if (typeof process.env === 'undefined' && typeof XMLHttpRequest !== 'undefined') {
      return;
    } else {
      if (typeof process !== 'undefined' && process.version) {
        // For Node.js environment
        data.lv = process.version;
      }
    }

    this.usageStatsData = data;
  }

  /**
   * Retrieves the current usage statistics.
   *
   * @returns Record containing boolean flags for various SDK features in use
   */
  getUsageStats(): Record<string, boolean | string | number> {
    return this.usageStatsData;
  }

  /**
   * Clears the usage statistics data.
   */
  clearUsageStats(): void {
    this.usageStatsData = {};
  }
}