@aller/blink/src/events/prepare-video-watch-event.ts

A library for tracking user behaviour.

import generalData from '../utils/general-data';
import { BlinkEvent } from '../types';
import {
  calculateVideoEventTime,
  VideoWatchEvent,
} from '../utils/video-event-time';
import { Page } from '../selectors/get-page-state';

export interface PrepareVideoWatchEventInput {
  page: Page;
  videoId: string;
  playerId: string;
  time?: Date;
}

export function prepareSingleVideoWatchEvent(
  videoId: string,
  generalData: any,
  watchEvent: VideoWatchEvent,
): BlinkEvent {
  const { startEvent, stopEvent, watchTime } = watchEvent;
  return {
    ...generalData,
    type: 'videoWatch',
    id: videoId,
    videoId,
    videoPlayVolume: startEvent.volume,
    videoStopVolume: stopEvent.volume,
    videoPlayPosition: startEvent.position,
    videoStopPosition: stopEvent.position,
    videoPlayReason: startEvent.reason,
    videoStopReason: stopEvent.reason,
    videoPlayMuted: startEvent.muted,
    videoStopMuted: stopEvent.muted,
    activeTime: watchTime,
  };
}

export default function prepareVideoWatchEvents(
  input: PrepareVideoWatchEventInput,
): BlinkEvent[] {
  const startEvents = calculateVideoEventTime(
    input.page.state.video.events,
    input.videoId,
    input.page.state.player,
    input.playerId,
    input.time || new Date(),
  );
  const general = generalData(input.page.state);
  const watchEvents = startEvents.length > 0 ? startEvents : [];

  return watchEvents.map(watchEvent =>
    prepareSingleVideoWatchEvent(input.videoId, general, watchEvent),
  );
}

export function getAllVideoWatchEventsPrepared(page: Page, time?: Date) {
  // Get all unique (videoId, playerId)-pairs from page
  const allIdPairs = page.state.video.events.map(
    ({ videoId, playerId }: { videoId: string; playerId: string }) => ({
      videoId,
      playerId,
    }),
  );

  const uniqueIdPairsObj = allIdPairs.reduce((register: any, idPair: any) => {
    register[idPair.videoId + idPair.playerId] = idPair;
    return register;
  }, {});

  const uniqueIdPairs: Array<{
    videoId: string;
    playerId: string;
  }> = Object.keys(uniqueIdPairsObj).map(key => uniqueIdPairsObj[key]);

  // Prepare all events for each (videoId, playerId)-pair, and merge them into a single list
  return uniqueIdPairs.reduce((all: any, { videoId, playerId }) => {
    const events = prepareVideoWatchEvents({ page, time, videoId, playerId });
    return all.concat(events);
  }, []);
}