feat(neuron-ui): add global apy estimation

packages/neuron-ui/src/components/NervosDAO/index.tsx

@@ -7,6 +7,7 @@ import appState from 'states/initStates/app'
 import { AppActions, StateWithDispatch } from 'states/stateProvider/reducer'
 import { updateNervosDaoData, clearNervosDaoData } from 'states/stateProvider/actionCreators'
 
+import calculateGlobalAPY from 'utils/calculateGlobalAPY'
 import calculateFee from 'utils/calculateFee'
 import { shannonToCKBFormatter, CKBToShannonFormatter } from 'utils/formatters'
 import { MIN_DEPOSIT_AMOUNT, MEDIUM_FEE_RATE, CapacityUnit } from 'utils/const'
@@ -28,6 +29,7 @@ const NervosDAO = ({
     loadings: { sending = false },
     tipBlockNumber,
     tipBlockHash,
+    tipBlockTimestamp,
     epoch,
   },
   wallet,
@@ -41,6 +43,7 @@ const NervosDAO = ({
   const [activeRecord, setActiveRecord] = useState<State.NervosDAORecord | null>(null)
   const [errorMessage, setErrorMessage] = useState('')
   const [withdrawList, setWithdrawList] = useState<(string | null)[]>([])
+  const [globalAPY, setGlobalAPY] = useState(0)
 
   const clearGeneratedTx = useCallback(() => {
     dispatch({
@@ -92,6 +95,14 @@ const NervosDAO = ({
     }
   }, [clearGeneratedTx, dispatch, updateDepositValue, wallet.id])
 
+  useEffect(() => {
+    if (tipBlockTimestamp) {
+      calculateGlobalAPY(tipBlockTimestamp).then(apy => {
+        setGlobalAPY(apy)
+      })
+    }
+  }, [tipBlockTimestamp])
+
   const onDepositDialogDismiss = () => {
     setShowDepositDialog(false)
     setDepositValue(`${MIN_DEPOSIT_AMOUNT}`)
@@ -278,9 +289,10 @@ const NervosDAO = ({
         <Text as="span" variant="small" block>{`Epoch number: ${epochInfo.number}`}</Text>
         <Text as="span" variant="small" block>{`Epoch index: ${epochInfo.index}`}</Text>
         <Text as="span" variant="small" block>{`Epoch length: ${epochInfo.length}`}</Text>
+        <Text as="span" variant="small" block>{`APY: ~${globalAPY}%`}</Text>
       </Stack>
     )
-  }, [epoch])
+  }, [epoch, globalAPY])
 
   return (
     <>

packages/neuron-ui/src/containers/Main/hooks.ts

@@ -40,6 +40,7 @@ export const useSyncChainData = ({ chainURL, dispatch }: { chainURL: string; dis
             payload: {
               tipBlockNumber: `${BigInt(header.number)}`,
               tipBlockHash: header.hash,
+              tipBlockTimestamp: +header.timestamp,
               chain: chainInfo.chain,
               difficulty: `${BigInt(chainInfo.difficulty)}`,
               epoch: chainInfo.epoch,

packages/neuron-ui/src/states/initStates/app.ts

@@ -3,6 +3,7 @@ import { CapacityUnit } from 'utils/const'
 const appState: State.App = {
   tipBlockNumber: '',
   tipBlockHash: '',
+  tipBlockTimestamp: 0,
   chain: '',
   difficulty: '',
   epoch: '',

packages/neuron-ui/src/tests/calculation/calculateGlobalAPY/fixtures.ts

@@ -0,0 +1,12 @@
+export default {
+  'return 0 if the genesis block is not loaded': {
+    currentTime: Date.now(),
+    genesisTime: undefined,
+    expectAPY: 0,
+  },
+  'one period and one handrand days': {
+    currentTime: new Date('2023-04-10').getTime(),
+    genesisTime: new Date('2019-01-01').getTime(),
+    expectAPY: 0.02369552868619654,
+  },
+}

packages/neuron-ui/src/tests/calculation/calculateGlobalAPY/index.test.ts

@@ -0,0 +1,16 @@
+import calculateGlobalAPY from 'utils/calculateGlobalAPY'
+import fixtures from './fixtures'
+
+describe('calculate the global apy', () => {
+  const fixtureTable = Object.entries(fixtures).map(([title, { currentTime, genesisTime, expectAPY }]) => [
+    title,
+    currentTime,
+    genesisTime,
+    expectAPY,
+  ])
+
+  test.each(fixtureTable)(`%s`, (_title, currentTime, genesisTime, expectAPY) => {
+    const apy = calculateGlobalAPY(currentTime, genesisTime)
+    expect(apy).toBe(expectAPY === 0 ? 0 : expectAPY.toFixed(2))
+  })
+})

packages/neuron-ui/src/types/App/index.d.ts

@@ -75,6 +75,7 @@ declare namespace State {
   interface App {
     tipBlockNumber: string
     tipBlockHash: string
+    tipBlockTimestamp: number
     chain: string
     difficulty: string
     epoch: string

packages/neuron-ui/src/utils/calculateGlobalAPY.ts

@@ -0,0 +1,48 @@
+import { getBlockByNumber } from '../services/chain'
+
+const INITIAL_OFFER = BigInt(33600000000)
+const SECONDARY_OFFER = BigInt(1344000000)
+const DAYS_PER_PERIOD = 365 * 4 * 1
+const MILLI_SECONDS_PER_DAY = 24 * 3600 * 1000
+const PERIOD_LENGTH = DAYS_PER_PERIOD * MILLI_SECONDS_PER_DAY
+
+let cachedGenesisTimestamp: number | undefined
+
+export default async (now: number, initialTimestamp: number | undefined = cachedGenesisTimestamp) => {
+  let genesisTimestamp = initialTimestamp
+  if (genesisTimestamp === undefined) {
+    genesisTimestamp = await getBlockByNumber('0x0')
+      .then(b => {
+        cachedGenesisTimestamp = +b.header.timestamp
+        return cachedGenesisTimestamp
+      })
+      .catch(() => undefined)
+  }
+  if (genesisTimestamp === undefined || now <= genesisTimestamp) {
+    return 0
+  }
+
+  const pastPeriods = BigInt(now - genesisTimestamp) / BigInt(PERIOD_LENGTH)
+  const pastDays = Math.ceil(((now - genesisTimestamp) % PERIOD_LENGTH) / MILLI_SECONDS_PER_DAY)
+
+  const realSecondaryOffer =
+    BigInt(4) * SECONDARY_OFFER * pastPeriods +
+    (BigInt(4) * SECONDARY_OFFER * BigInt(pastDays)) / BigInt(DAYS_PER_PERIOD)
+
+  let realPrimaryOffer = BigInt(0)
+
+  let PRIMARY_OFFER = INITIAL_OFFER
+  for (let i = 0; i < Number(pastPeriods); i++) {
+    PRIMARY_OFFER /= BigInt(2)
+    const offer = PRIMARY_OFFER
+    realPrimaryOffer += offer
+  }
+
+  PRIMARY_OFFER /= BigInt(2)
+
+  const primaryOfferFraction = (BigInt(pastDays) * PRIMARY_OFFER) / BigInt(DAYS_PER_PERIOD)
+  realPrimaryOffer += primaryOfferFraction
+
+  const totalOffer = INITIAL_OFFER + realPrimaryOffer + realSecondaryOffer
+  return +(Number(SECONDARY_OFFER) / Number(totalOffer)).toFixed(2)
+}