Feat/notifications update

src/mail-scheduler/index.ts

@@ -5,6 +5,7 @@ import { ConfigVariable, config } from '../utils/config'
 import { uniqueId } from '../utils/crypto'
 import { globalEm } from '../utils/globalEm'
 import { createMailContent, executeMailDelivery } from './utils'
+import { updateJoystreamPrice } from '../utils/joystreamPrice'
 
 export async function getMaxAttempts(em: EntityManager): Promise<number> {
   const maxAttempts = await config.get(ConfigVariable.EmailNotificationDeliveryMaxAttempts, em)
@@ -31,6 +32,7 @@ export async function mailsToDeliver(em: EntityManager): Promise<NotificationEma
 
 export async function deliverEmails() {
   const em = await globalEm
+  await updateJoystreamPrice()
   const newEmailDeliveries = await mailsToDeliver(em)
   const maxAttempts = await getMaxAttempts(em)
   const appName = await config.get(ConfigVariable.AppName, em)

src/utils/joystreamPrice.ts

@@ -0,0 +1,53 @@
+import { createLogger } from '@subsquid/logger'
+import BN from 'bn.js'
+
+export let JOYSTREAM_USD_PRICE: number | null = null
+
+const HAPI_TO_JOY_RATE = 10 ** 10
+const HAPI_TO_JOY_RATE_BN = new BN(HAPI_TO_JOY_RATE)
+const MAX_SAFE_NUMBER_BN = new BN(Number.MAX_SAFE_INTEGER)
+
+const log = createLogger('price')
+
+export const updateJoystreamPrice = async () => {
+  // we don't care if the request fails, app should continue to work w/o joy price
+  const data = await fetch('https://status.joystream.org/price').catch(() =>
+    log.error('Fetching JOYSTREAM price failed')
+  )
+  if (data) {
+    const json = await data.json()
+    JOYSTREAM_USD_PRICE = +json.price ?? 0
+  }
+}
+
+export const schedulePriceUpdate = async (): Promise<void> => {
+  while (true) {
+    await updateJoystreamPrice()
+    log.info(`Price refetched: ${JOYSTREAM_USD_PRICE}`)
+    await new Promise((resolve) => setTimeout(resolve, 1_000 * 60 * 5)) // 5mins
+  }
+}
+
+export const convertHapiToUSD = (hapis: BN | bigint, round = true) => {
+  if (!JOYSTREAM_USD_PRICE) return null
+  const tokens = hapiBnToTokenNumber(new BN(hapis.toString()))
+  const amount = tokens * JOYSTREAM_USD_PRICE
+  return round ? Math.round(amount) : amount
+}
+
+const hapiBnToTokenNumber = (bn: BN, roundUpToTwoDecimalPlaces?: boolean) => {
+  const wholeUnitsBn = bn.div(HAPI_TO_JOY_RATE_BN)
+  const fractionalUnitsBn = bn.mod(HAPI_TO_JOY_RATE_BN)
+
+  if (wholeUnitsBn.gt(MAX_SAFE_NUMBER_BN)) {
+    throw new Error('Trying to convert unsafe number from BN to number')
+  }
+
+  const wholeUnits = wholeUnitsBn.toNumber()
+  const fractionalHapiUnits = fractionalUnitsBn.toNumber()
+  const fractionalJoyUnits = fractionalHapiUnits / HAPI_TO_JOY_RATE
+  if (roundUpToTwoDecimalPlaces) {
+    return Math.ceil((wholeUnits + fractionalJoyUnits) * 100) / 100
+  }
+  return wholeUnits + fractionalJoyUnits
+}