src/analytics/lib.ts

// Copyright 2024 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Main analytics library. Defines extension-specific interfaces and provides the addEvent API.

// Exception: valid use of snake_case for property name to match the json field name
/* eslint-disable @typescript-eslint/naming-convention */

import { send, type UserProperties, type Measurement, type Event, createMeasurement } from './ga4';
import { AnalyticsInfo } from './info';
import { AnalyticsState } from './state';

interface FuchsiaUserProperties {
  [key: string]: string | number | boolean | undefined;
  os?: string;
  arch?: string;
  version?: string;
  bot?: boolean;
  internal: boolean;
  metrics_level: number;
}

class FuchsiaUserPropertiesEncoded implements UserProperties {
  [key: keyof (FuchsiaUserProperties)]: UserProperties[keyof (UserProperties)];
  constructor(properties: FuchsiaUserProperties) {
    for (const [index, value] of Object.entries(properties)) {
      if (value !== undefined) {
        this[index] = { value: value };
      }
    }
  }
}

/**
 * When analytics is allowed, wrap an Event in a Measurement and send it to the GA4 endpoint
 * @param event the Event to send
 */
export async function addEvent(event: Event): Promise<void> {
  if (AnalyticsState.optInLevel === 0 || !AnalyticsInfo.uuid) {
    return;
  }

  const userProperties = new FuchsiaUserPropertiesEncoded(
    {
      os: AnalyticsInfo.os,
      arch: AnalyticsInfo.arch,
      version: AnalyticsInfo.extensionVersion,
      internal: AnalyticsInfo.isInternalUser,
      metrics_level: AnalyticsState.optInLevel,
    });

  const measurement: Measurement = createMeasurement(AnalyticsInfo.uuid, [event], userProperties);

  await send(measurement, AnalyticsState.debugLevel);
}