ilp-plugin-virtual/integration-test/ilp-kit/api/src/lib/activity.js

ILP virtual ledger plugin for directly transacting connectors

'use strict'

const _ = require('lodash')
const moment = require('moment')
const Log = require('../lib/log')
const Config = require('../lib/config')
const Socket = require('../lib/socket')
const ActivityLogFactory = require('../models/activity_log')
const UserFactory = require('../models/user')

const cacheLifetime = 30 * 60 // seconds

module.exports = class Activity {
  constructor (deps) {
    this.log = deps(Log)('activity')
    this.config = deps(Config)
    this.socket = deps(Socket)
    this.ActivityLog = deps(ActivityLogFactory)
    this.User = deps(UserFactory)

    // TODO:PERFORMANCE use Redis
    this.paymentGroupCache = {}

    setInterval(this.paymentGroupCacheCleanup.bind(this), 60000) // runs every minute
  }

  async processPayment (payment, user) {
    this.log.info(`Processing payment ${payment.id} for ${user.username}`)

    // This payment doesn't affect the given user
    if (payment.source_user !== user.id && payment.destination_user !== user.id) return

    const cacheId = payment.source_identifier +
      payment.destination_identifier +
      payment.message +
      user.id
    const cache = this.paymentGroupCache[cacheId]

    let activityLog

    if (!cache) {
      activityLog = new this.ActivityLog()
      activityLog.user_id = user.id
      activityLog.stream_id = payment.stream_id
      activityLog = await activityLog.save()
    } else {
      // Cache exists, which means there was a payment between source and destination
      // with the same message, and the same side of activity within the past 30 mins
      activityLog = cache.activityLog
      activityLog.changed('updated_at', true)
      await activityLog.save()
    }

    // Add the payment to the activity
    await activityLog.addPayment(payment)

    // Add the payment to the recent payments cache (used for grouping)
    this.paymentGroupCache[cacheId] = {
      recentDate: payment.created_at,
      // TODO:PERFORMANCE might be better to keep the activityLog.id instead of the whole object
      activityLog
    }

    // TODO:PERFORMANCE figure out a way to send a socket message for a single payment
    // instead of the whole activity (if the client already has a track of this activity)
    activityLog = await this.ActivityLog.getActivityLog(activityLog.id)

    // Notify the clients
    this.socket.activity(user.username, activityLog)
  }

  async processSettlement (settlement) {
    this.log.info(`Processing settlement ${settlement.id}`)

    // TODO handle peer settlement
    if (!settlement.user_id) return

    // TODO:PERFORMANCE avoid this call, we only do it to get the username
    const user = await this.User.findOne({ where: { id: settlement.user_id } })

    let activityLog = new this.ActivityLog()
    activityLog.user_id = settlement.user_id
    activityLog = await activityLog.save()

    // Add the settlement to the activity
    await activityLog.addSettlement(settlement)

    activityLog = await this.ActivityLog.getActivityLog(activityLog.id)

    // Notify the clients
    this.socket.activity(user.username, activityLog)
  }

  async processWithdrawal (withdrawal) {
    this.log.info(`Processing withdrawal. ${withdrawal.id}`)

    // TODO:PERFORMANCE avoid this call, we only do it to get the username
    const user = await this.User.findOne({ where: { id: withdrawal.user_id } })

    let activityLog = new this.ActivityLog()
    activityLog.user_id = withdrawal.user_id
    activityLog = await activityLog.save()

    // Add the withdrawal to the activity
    await activityLog.addWithdrawal(withdrawal)

    activityLog = await this.ActivityLog.getActivityLog(activityLog.id)

    // Notify the clients
    this.socket.activity(user.username, activityLog)
  }

  paymentGroupCacheCleanup () {
    this.paymentGroupCache = _.pickBy(this.paymentGroupCache,
      group => moment(group.recentDate).add(cacheLifetime, 'seconds') > moment())
  }
}