Merge pull request #3548 from gradido/frontend_fix_link_send_message

feat(frontend): make link send confirmation dialog more accurate

backend/src/graphql/resolver/TransactionLinkResolver.ts

@@ -14,7 +14,7 @@ import { User } from '@model/User'
 import { QueryLinkResult } from '@union/QueryLinkResult'
 import { Decay, interpretEncryptedTransferArgs, TransactionTypeId } from 'core'
 import {
-  AppDatabase, Community as DbCommunity, Contribution as DbContribution,
+  AppDatabase, Contribution as DbContribution,
   ContributionLink as DbContributionLink, FederatedCommunity as DbFederatedCommunity, Transaction as DbTransaction,
   TransactionLink as DbTransactionLink,
   User as DbUser,
@@ -36,7 +36,7 @@ import { Context, getClientTimezoneOffset, getUser } from '@/server/context'
 import { calculateBalance } from '@/util/validate'
 import { fullName } from 'core'
 import { TRANSACTION_LINK_LOCK, TRANSACTIONS_LOCK } from 'database'
-import { calculateDecay, decode, DisburseJwtPayloadType, encode, encryptAndSign, EncryptedJWEJwtPayloadType, RedeemJwtPayloadType, verify } from 'shared'
+import { calculateDecay, compoundInterest, decayFormula, decode, DisburseJwtPayloadType, encode, encryptAndSign, EncryptedJWEJwtPayloadType, RedeemJwtPayloadType, verify } from 'shared'
 
 import { LOG4JS_BASE_CATEGORY_NAME } from '@/config/const'
 import { DisbursementClient as V1_0_DisbursementClient } from '@/federation/client/1_0/DisbursementClient'
@@ -48,7 +48,6 @@ import { randombytes_random } from 'sodium-native'
 import { executeTransaction } from './TransactionResolver'
 import {
   getAuthenticatedCommunities,
-  getCommunityByIdentifier,
   getCommunityByPublicKey,
   getCommunityByUuid,
 } from './util/communities'
@@ -90,7 +89,7 @@ export class TransactionLinkResolver {
     const createdDate = new Date()
     const validUntil = transactionLinkExpireDate(createdDate)
 
-    const holdAvailableAmount = amount.minus(calculateDecay(amount, createdDate, validUntil).decay)
+    const holdAvailableAmount = compoundInterest(amount, CODE_VALID_DAYS_DURATION * 24 * 60 * 60)
 
     // validate amount
     const sendBalance = await calculateBalance(user.id, holdAvailableAmount.mul(-1), createdDate)

frontend/src/components/GddSend/TransactionConfirmationLink.vue

@@ -20,20 +20,29 @@
         <BCol>{{ $t('advanced-calculation') }}</BCol>
       </BRow>
       <BRow class="pe-3" offset="2">
-        <BCol offset="2">{{ $t('form.current_balance') }}</BCol>
+        <BCol offset="2">{{ $t('form.current_available') }}</BCol>
         <BCol>{{ $filters.GDD(balance) }}</BCol>
       </BRow>
       <BRow class="pe-3">
         <BCol offset="2">
-          <strong>{{ $t('form.your_amount') }}</strong>
+          <strong>{{ $t('form.link_amount') }}</strong>
         </BCol>
-        <BCol class="borderbottom">
+        <BCol>
           <strong>{{ $filters.GDD(amount * -1) }}</strong>
         </BCol>
       </BRow>
       <BRow class="pe-3">
-        <BCol offset="2">{{ $t('form.new_balance') }}</BCol>
-        <BCol>{{ $filters.GDD(balance - amount) }}</BCol>
+        <BCol offset="2">{{ $t('decay.decay') }}</BCol>
+        <BCol class="borderbottom">{{ $filters.GDD(amount - blockedAmount) }}</BCol>
+      </BRow>
+      <BRow class="pe-3">
+        <BCol offset="2">{{ $t('form.available_after') }}</BCol>
+        <BCol>{{ $filters.GDD(balance - blockedAmount) }}</BCol>
+      </BRow>
+      <BRow class="pe-6 mt-2">
+        <BCol offset="1">
+          <small>{{ $t('form.link_decay_description') }}</small>
+        </BCol>
       </BRow>
       <BRow class="mt-5">
         <BCol cols="12" md="6" lg="6">
@@ -57,6 +66,7 @@
   </div>
 </template>
 <script>
+import { LINK_COMPOUND_INTEREST_FACTOR } from '@/constants'
 export default {
   name: 'TransactionConfirmationLink',
   props: {
@@ -68,7 +78,13 @@ export default {
   },
   computed: {
     totalBalance() {
-      return this.balance - this.amount * 1.028
+      return this.balance - this.blockedAmount
+    },
+    blockedAmount() {
+      // correct formula
+      return this.amount * LINK_COMPOUND_INTEREST_FACTOR
+      // same formula as in backend
+      // return 2 * this.amount - this.amount * Math.pow(0.99999997803504048, 1209600)
     },
     disabled() {
       if (this.totalBalance < 0) {

frontend/src/constants.js

@@ -1,2 +1,5 @@
 export const GDD_PER_HOUR = 20
 export const PAGE_SIZE = 25
+// compound interest factor (decay reversed) for 14 days (hard coded backend link timeout)
+// 365.2425 days per year (gregorian calendar year)
+export const LINK_COMPOUND_INTEREST_FACTOR = Math.pow(2, 14 / 365.2425)

frontend/src/locales/de.json

@@ -164,10 +164,12 @@
   "form": {
     "amount": "Betrag",
     "at": "am",
+    "available_after": "Verfügbar nach Bestätigung",
     "cancel": "Abbrechen",
     "change": "Ändern",
     "check_now": "Jetzt prüfen",
     "close": "Schließen",
+    "current_available": "Aktuell verfügbar",
     "current_balance": "Aktueller Kontostand",
     "date": "Datum",
     "description": "Beschreibung",
@@ -178,6 +180,8 @@
     "hours": "Stunden",
     "identifier": "Email, Nutzername oder Gradido ID",
     "lastname": "Nachname",
+    "link_amount": "Link-Betrag",
+    "link_decay_description": "Der Link-Betrag wird zusammen mit der maximalen Vergänglichkeit blockiert. Nach Einlösen, Verfallen oder Löschen des Links wird der Rest wieder freigegeben.",
     "memo": "Nachricht",
     "message": "Nachricht",
     "new_balance": "Neuer Kontostand nach Bestätigung",

frontend/src/locales/en.json

@@ -164,10 +164,12 @@
   "form": {
     "amount": "Amount",
     "at": "at",
+    "available_after": "Available after confirmation",
     "cancel": "Cancel",
     "change": "Change",
     "check_now": "Check now",
     "close": "Close",
+    "current_available": "Currently available",
     "current_balance": "Current Balance",
     "date": "Date",
     "description": "Description",
@@ -178,6 +180,8 @@
     "hours": "Hours",
     "identifier": "Email, username or gradido ID",
     "lastname": "Lastname",
+    "link_amount": "Link amount",
+    "link_decay_description": "The link amount is blocked along with the maximum decay. After the link has been redeemed, expired, or deleted, the rest is released again.",
     "memo": "Message",
     "message": "Message",
     "new_balance": "Account balance after confirmation",

frontend/src/locales/es.json

@@ -146,10 +146,12 @@
   "form": {
     "amount": "Importe",
     "at": "am",
+    "available_after": "Disponible tras la confirmación",
     "cancel": "Cancelar",
     "change": "Cambiar",
     "check_now": "Revisar",
     "close": "Cerrar",
+    "current_available": "Actualmente disponible",
     "current_balance": "Saldo de cuenta actual",
     "date": "Fecha",
     "description": "Descripción",
@@ -158,6 +160,8 @@
     "from": "De",
     "generate_now": "crear ahora",
     "lastname": "Apellido",
+    "link_amount": "Importe del enlace",
+    "link_decay_description": "El importe del enlace se bloquea junto con la ransience máxima. Una vez que el enlace se ha canjeado, caducado o eliminado, el resto se libera de nuevo.",
     "memo": "Mensaje",
     "message": "Noticia",
     "new_balance": "Saldo de cuenta nuevo depués de confirmación",

frontend/src/locales/fr.json

@@ -151,10 +151,12 @@
   "form": {
     "amount": "Montant",
     "at": "à",
+    "available_after": "Disponible après confirmation",
     "cancel": "Annuler",
     "change": "Changer",
     "check_now": "Vérifier maintenant",
     "close": "Fermer",
+    "current_available": "Actuellement disponible",
     "current_balance": "Solde actuel",
     "date": "Date",
     "description": "Description",
@@ -164,6 +166,8 @@
     "generate_now": "Produire maintenant",
     "hours": "Heures",
     "lastname": "Nom",
+    "link_amount": "Montant du lien",
+    "link_decay_description": "Le montant du lien est bloqué avec le dépérissement maximale. Une fois le lien utilisé, expiré ou supprimé, le reste est à nouveau débloqué.",
     "memo": "Note",
     "message": "Message",
     "new_balance": "Montant du solde après confirmation",

frontend/src/locales/nl.json

@@ -146,10 +146,12 @@
   "form": {
     "amount": "Bedrag",
     "at": "op",
+    "available_after": "Beschikbaar na bevestiging",
     "cancel": "Annuleren",
     "change": "Wijzigen",
     "check_now": "Nu controleren",
     "close": "Sluiten",
+    "current_available": "Momenteel beschikbaar",
     "current_balance": "Actueel banksaldo",
     "date": "Datum",
     "description": "Beschrijving",
@@ -158,6 +160,8 @@
     "from": "Van",
     "generate_now": "Nu genereren",
     "lastname": "Achternaam",
+    "link_amount": "Linkbedrag",
+    "link_decay_description": "Het linkbedrag wordt geblokkeerd samen met de maximale vergankelijkheid. Nadat de link is ingewisseld, verlopen of verwijderd, wordt het resterende bedrag weer vrijgegeven.",
     "memo": "Memo",
     "message": "Bericht",
     "new_balance": "Nieuw banksaldo na bevestiging",

shared/src/const/index.ts

@@ -1,3 +1,4 @@
 export const DECAY_START_TIME = new Date('2021-05-13T17:46:31Z')
+export const SECONDS_PER_YEAR_GREGORIAN_CALENDER = 31556952.0
 export const LOG4JS_BASE_CATEGORY_NAME = 'shared'
 export const REDEEM_JWT_TOKEN_EXPIRATION = '10m'

shared/src/logic/decay.test.ts

@@ -1,6 +1,6 @@
 import { Decimal } from 'decimal.js-light'
 
-import { calculateDecay, decayFormula } from './decay'
+import { calculateDecay, compoundInterest, decayFormula, decayFormulaFast } from './decay'
 
 describe('utils/decay', () => {
   describe('decayFormula', () => {
@@ -10,6 +10,18 @@ describe('utils/decay', () => {
       // TODO: toString() was required, we could not compare two decimals
       expect(decayFormula(amount, seconds).toString()).toBe('0.999999978035040489732012')
     })
+
+    it('with large values', () => {
+      const amount = new Decimal(100.0)
+      const seconds = 1209600
+      expect(decayFormula(amount, seconds).toString()).toBe('97.3781030481034505778419')
+    })
+
+    it('with one year', () => {
+      const amount = new Decimal(100.0)
+      const seconds = 31556952
+      expect(decayFormula(amount, seconds).toString()).toBe('49.99999999999999999999999')
+    })
     
     it('has correct backward calculation', () => {
       const amount = new Decimal(1.0)
@@ -26,6 +38,40 @@ describe('utils/decay', () => {
       expect(decayFormula(amount, seconds).toString()).toBe('1.0')
     })
   })
+
+  describe('decayFormulaFast', () => {
+    it('work like expected with small values', () => {
+      const amount = new Decimal(1.0)
+      const seconds = 1
+      expect(decayFormulaFast(amount, seconds).toString()).toBe('0.999999978035040489732012')
+    })
+    it('work like expected with large values', () => {
+      const amount = new Decimal(100.0)
+      const seconds = 1209600
+      expect(decayFormulaFast(amount, seconds).toString()).toBe('97.3781030481034505778419')
+    })
+    it('work like expected with one year', () => {
+      const amount = new Decimal(100.0)
+      const seconds = 31556952
+      expect(decayFormulaFast(amount, seconds).toString()).toBe('50')
+    })
+    it('work correct when calculating future decay', () => {
+      // for example on linked transaction
+      // if I have amount = 100 GDD and want to know how much GDD I must lock to able to pay
+      // decay in 14 days (1209600 seconds)
+      const amount = new Decimal(100.0)
+      const seconds = 1209600
+      expect(compoundInterest(amount, seconds).toString()).toBe('102.6924912992003635568199')
+      // if I lock 102.6924912992003635568199 GDD, I will have 99.99999999999999999999998 GDD after 14 days, not 100% but near enough
+      expect(decayFormulaFast(compoundInterest(amount, seconds), seconds).toString()).toBe('99.99999999999999999999998')
+      expect(compoundInterest(amount, seconds).toDecimalPlaces(4).toString()).toBe('102.6925')
+      // rounded to 4 decimal places it is working like a charm
+      expect(decayFormulaFast(new Decimal(
+        compoundInterest(amount, seconds).toDecimalPlaces(4)), 
+        seconds
+      ).toDecimalPlaces(4).toString()).toBe('100')
+    })
+  })
   
   it('has base 0.99999997802044727', () => {
     const now = new Date()

shared/src/logic/decay.ts

@@ -1,6 +1,6 @@
 import { Decimal } from 'decimal.js-light'
 
-import { DECAY_START_TIME } from '../const'
+import { DECAY_START_TIME, SECONDS_PER_YEAR_GREGORIAN_CALENDER } from '../const'
 
 Decimal.set({
   precision: 25,
@@ -26,6 +26,13 @@ export function decayFormula(value: Decimal, seconds: number): Decimal {
   )
 }
 
+export function decayFormulaFast(value: Decimal, seconds: number): Decimal {
+  return value.mul(new Decimal(2).pow(new Decimal(-seconds).div(new Decimal(SECONDS_PER_YEAR_GREGORIAN_CALENDER))))
+}
+export function compoundInterest(value: Decimal, seconds: number): Decimal {
+  return value.mul(new Decimal(2).pow(new Decimal(seconds).div(new Decimal(SECONDS_PER_YEAR_GREGORIAN_CALENDER))))
+}
+
 export function calculateDecay(
   amount: Decimal,
   from: Date,