snowplow/snowplow-javascript-tracker

/*
 * Copyright (c) 2022 Snowplow Analytics Ltd, 2010 Anthon Pang
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import { SelfDescribingJson } from '@snowplow/tracker-core';
import { BrowserPlugin } from '@snowplow/browser-tracker-core';
import { Geolocation } from './contexts';

const _trackers: Record<string, [boolean, SelfDescribingJson<Geolocation> | undefined]> = {};

let geolocation: SelfDescribingJson<Geolocation>,
  geolocationContextAdded = false;

/**
 * Captures the geolocation information from the users browser
 * The geolocation will be cached and will be only be requested once
 * @param enableAtLoad - Should the geolocation context be populated immediately
 *
 * @remarks
 * Enabling this will produce a popup for the user asking for permission to read their location information
 */
export function GeolocationPlugin(enableAtLoad: boolean = false): BrowserPlugin {
  let trackerId: string;

  return {
    activateBrowserPlugin: (tracker) => {
      trackerId = tracker.id;
      _trackers[tracker.id] = [false, undefined];

      if (enableAtLoad) {
        enableGeolocationContext([trackerId]);
      }
    },
    contexts: () => {
      let context = _trackers[trackerId]?.[1];
      if (context) {
        return [context];
      }

      return [];
    },
  };
}

/**
 * Attempts to create a context using the geolocation API
 *
 * @param trackers - The tracker identifiers which the context will be sent to
 */
export function enableGeolocationContext(trackers: Array<string> = Object.keys(_trackers)) {
  const navigatorAlias = navigator;

  trackers.forEach((t) => {
    //Mark as enabled
    _trackers[t] = [true, geolocation]; // Geolocation might still be undefined but it could also be set already
  });

  if (!geolocationContextAdded && navigatorAlias.geolocation && navigatorAlias.geolocation.getCurrentPosition) {
    geolocationContextAdded = true;
    navigatorAlias.geolocation.getCurrentPosition(function (position) {
      var coords = position.coords;
      geolocation = {
        schema: 'iglu:com.snowplowanalytics.snowplow/geolocation_context/jsonschema/1-1-0',
        data: {
          latitude: coords.latitude,
          longitude: coords.longitude,
          latitudeLongitudeAccuracy: coords.accuracy,
          altitude: coords.altitude,
          altitudeAccuracy: coords.altitudeAccuracy,
          bearing: coords.heading,
          speed: coords.speed,
          timestamp: Math.round(position.timestamp),
        },
      };

      // Ensure all trackers with geolocation enabled have the context set
      for (const key in _trackers) {
        if (Object.prototype.hasOwnProperty.call(_trackers, key) && _trackers[key][0]) {
          _trackers[key] = [true, geolocation];
        }
      }
    });
  }
}