standardnotes-server/packages/analytics/src/Domain/Handler/SubscriptionCancelledEventHandler.ts

import { DomainEventHandlerInterface, SubscriptionCancelledEvent } from '@standardnotes/domain-events'
import { inject, injectable, optional } from 'inversify'
import { Logger } from 'winston'
import { Username } from '@standardnotes/domain-core'
import { Mixpanel } from 'mixpanel'

import TYPES from '../../Bootstrap/Types'
import { AnalyticsActivity } from '../Analytics/AnalyticsActivity'
import { AnalyticsStoreInterface } from '../Analytics/AnalyticsStoreInterface'
import { StatisticsStoreInterface } from '../Statistics/StatisticsStoreInterface'
import { SubscriptionEventType } from '../Subscription/SubscriptionEventType'
import { SubscriptionPlanName } from '../Subscription/SubscriptionPlanName'
import { Period } from '../Time/Period'
import { GetUserAnalyticsId } from '../UseCase/GetUserAnalyticsId/GetUserAnalyticsId'
import { SaveRevenueModification } from '../UseCase/SaveRevenueModification/SaveRevenueModification'
import { StatisticMeasureName } from '../Statistics/StatisticMeasureName'
import { TimerInterface } from '@standardnotes/time'

@injectable()
export class SubscriptionCancelledEventHandler implements DomainEventHandlerInterface {
  constructor(
    @inject(TYPES.GetUserAnalyticsId) private getUserAnalyticsId: GetUserAnalyticsId,
    @inject(TYPES.AnalyticsStore) private analyticsStore: AnalyticsStoreInterface,
    @inject(TYPES.StatisticsStore) private statisticsStore: StatisticsStoreInterface,
    @inject(TYPES.SaveRevenueModification) private saveRevenueModification: SaveRevenueModification,
    @inject(TYPES.Logger) private logger: Logger,
    @inject(TYPES.MixpanelClient) @optional() private mixpanelClient: Mixpanel | null,
    @inject(TYPES.Timer) private timer: TimerInterface,
  ) {}

  async handle(event: SubscriptionCancelledEvent): Promise<void> {
    const { analyticsId, userUuid } = await this.getUserAnalyticsId.execute({ userEmail: event.payload.userEmail })
    await this.analyticsStore.markActivity([AnalyticsActivity.SubscriptionCancelled], analyticsId, [
      Period.Today,
      Period.ThisWeek,
      Period.ThisMonth,
    ])

    await this.trackSubscriptionStatistics(event)

    const result = await this.saveRevenueModification.execute({
      billingFrequency: event.payload.billingFrequency,
      eventType: SubscriptionEventType.create(event.type).getValue(),
      newSubscriber: event.payload.userExistingSubscriptionsCount === 1,
      payedAmount: event.payload.payAmount,
      planName: SubscriptionPlanName.create(event.payload.subscriptionName).getValue(),
      subscriptionId: event.payload.subscriptionId,
      username: Username.create(event.payload.userEmail).getValue(),
      userUuid,
    })

    if (result.isFailed()) {
      this.logger.error(
        `[${event.type}][${event.payload.subscriptionId}] Could not save revenue modification: ${result.getError()}`,
      )
    }

    if (this.mixpanelClient !== null) {
      this.mixpanelClient.track(event.type, {
        distinct_id: analyticsId.toString(),
        subscription_name: event.payload.subscriptionName,
        subscription_created_at: this.timer.convertMicrosecondsToDate(event.payload.subscriptionCreatedAt),
        subscription_updated_at: this.timer.convertMicrosecondsToDate(event.payload.subscriptionUpdatedAt),
        last_payed_at: this.timer.convertMicrosecondsToDate(event.payload.lastPayedAt),
        subscription_ends_at: this.timer.convertMicrosecondsToDate(event.payload.subscriptionEndsAt),
        offline: event.payload.offline,
        replaced: event.payload.replaced,
        user_existing_subscriptions_count: event.payload.userExistingSubscriptionsCount,
        billing_frequency: event.payload.billingFrequency,
        pay_amount: event.payload.payAmount,
      })
    }
  }

  private async trackSubscriptionStatistics(event: SubscriptionCancelledEvent) {
    if (this.isLegacy5yearSubscriptionPlan(event.payload.subscriptionEndsAt, event.payload.subscriptionCreatedAt)) {
      return
    }

    const subscriptionLength = event.payload.timestamp - event.payload.subscriptionCreatedAt
    await this.statisticsStore.incrementMeasure(StatisticMeasureName.NAMES.SubscriptionLength, subscriptionLength, [
      Period.Today,
      Period.ThisWeek,
      Period.ThisMonth,
    ])

    const remainingSubscriptionTime = event.payload.subscriptionEndsAt - event.payload.timestamp
    const totalSubscriptionTime = event.payload.subscriptionEndsAt - event.payload.lastPayedAt

    const remainingSubscriptionPercentage = Math.floor((remainingSubscriptionTime / totalSubscriptionTime) * 100)

    await this.statisticsStore.incrementMeasure(
      StatisticMeasureName.NAMES.RemainingSubscriptionTimePercentage,
      remainingSubscriptionPercentage,
      [Period.Today, Period.ThisWeek, Period.ThisMonth],
    )
  }

  private isLegacy5yearSubscriptionPlan(subscriptionEndsAt: number, subscriptionCreatedAt: number) {
    const fourYearsInMicroseconds = 126_230_400_000_000

    return subscriptionEndsAt - subscriptionCreatedAt > fourYearsInMicroseconds
  }
}