From d9666f3a8834de0dc5176920ef8a36b97779e359 Mon Sep 17 00:00:00 2001
From: einhornimmond <info@einhornimmond.de>
Date: Tue, 30 Dec 2025 18:13:03 +0100
Subject: [PATCH] move transaction link validUntil correction into database
 migration

---
 ...097-fix_production_data_for_blockchain2.ts | 78 +++++++++++++++++++
 .../TransactionLinkFundingsSync.role.ts       | 31 +-------
 .../db-v2.7.0_to_blockchain-v3.5/utils.ts     |  4 -
 shared/src/const/index.ts                     |  3 +
 shared/src/logic/decay.ts                     | 13 +++-
 5 files changed, 93 insertions(+), 36 deletions(-)

diff --git a/database/migration/migrations/0097-fix_production_data_for_blockchain2.ts b/database/migration/migrations/0097-fix_production_data_for_blockchain2.ts
index f8f2fdd57..f7c99561d 100644
--- a/database/migration/migrations/0097-fix_production_data_for_blockchain2.ts
+++ b/database/migration/migrations/0097-fix_production_data_for_blockchain2.ts
@@ -1,3 +1,10 @@
+import Decimal from 'decimal.js-light'
+import { DECAY_FACTOR, reverseLegacyDecay } from 'shared'
+
+function calculateEffectiveSeconds(holdOriginal: Decimal, holdCorrected: Decimal): Decimal {
+  return holdOriginal.div(holdCorrected).ln().div(DECAY_FACTOR.ln())
+}
+
 export async function upgrade(queryFn: (query: string, values?: any[]) => Promise<Array<any>>) {
   /**
    * Migration: Correct historical inconsistencies in transactions, users, and contribution_links.
@@ -34,6 +41,77 @@ export async function upgrade(queryFn: (query: string, values?: any[]) => Promis
    *     ensuring blockchain consistency for contributions.
    */
 
+  /**
+   * Fix 0: Update transaction links to match holdAvailableAmount with validUntil, because the old formula lead to incorrect values
+   */
+
+  let sumCount = 0
+  let count = 0
+  let lastProcessedId = 0
+  const LIMIT = 200
+  do {
+    const rows = await queryFn(
+      `
+      SELECT id, amount, hold_available_amount, validUntil, createdAt, redeemedAt, deletedAt
+      FROM transaction_links
+      WHERE id > ?
+      ORDER BY id ASC
+      LIMIT ?
+    `,
+      [lastProcessedId, LIMIT],
+    )
+    if (!rows.length) {
+      break
+    }
+    const updates: Array<{ id: number; newValidUntil: string }> = []
+    for (const row of rows) {
+      const validUntil = new Date(row.validUntil)
+      const redeemedAt = row.redeemedAt ? new Date(row.redeemedAt) : null
+      const deletedAt = row.deletedAt ? new Date(row.deletedAt) : null
+      const createdAt = new Date(row.createdAt)
+      const amount = new Decimal(row.amount)
+      const duration = (validUntil.getTime() - createdAt.getTime()) / 1000
+      const blockedAmountCorrected = reverseLegacyDecay(amount, duration)
+      // fix only if the difference is big enough to have an impact
+      if (blockedAmountCorrected.sub(amount).abs().lt(new Decimal('0.001'))) {
+        continue
+      }
+      const holdAvailableAmount = new Decimal(row.hold_available_amount)
+      const secondsDiff = calculateEffectiveSeconds(
+        new Decimal(holdAvailableAmount.toString()),
+        new Decimal(blockedAmountCorrected.toString()),
+      )
+      const newValidUntil = new Date(validUntil.getTime() - secondsDiff.mul(1000).toNumber())
+      if (
+        (redeemedAt && redeemedAt.getTime() < validUntil.getTime()) ||
+        (deletedAt && deletedAt.getTime() < validUntil.getTime())
+      ) {
+        continue
+      }
+      updates.push({
+        id: row.id,
+        newValidUntil: newValidUntil.toISOString().replace('T', ' ').replace('Z', ''),
+      })
+    }
+    if (updates.length > 0) {
+      const caseStatements = updates.map((u) => `WHEN ${u.id} THEN '${u.newValidUntil}'`).join('\n')
+
+      await queryFn(
+        `
+        UPDATE transaction_links
+        SET validUntil = CASE id
+          ${caseStatements}
+        END
+        WHERE id IN (?)
+      `,
+        [updates.map((u) => u.id)],
+      )
+      sumCount += updates.length
+    }
+    count = rows.length
+    lastProcessedId = rows[rows.length - 1].id
+  } while (count === LIMIT)
+  ///*/
   /**
    * Fix 1: Remove self-signed contributions.
    *
diff --git a/dlt-connector/src/migrations/db-v2.7.0_to_blockchain-v3.5/interaction/syncDbWithBlockchain/TransactionLinkFundingsSync.role.ts b/dlt-connector/src/migrations/db-v2.7.0_to_blockchain-v3.5/interaction/syncDbWithBlockchain/TransactionLinkFundingsSync.role.ts
index 6a28d4b7f..dc4032f68 100644
--- a/dlt-connector/src/migrations/db-v2.7.0_to_blockchain-v3.5/interaction/syncDbWithBlockchain/TransactionLinkFundingsSync.role.ts
+++ b/dlt-connector/src/migrations/db-v2.7.0_to_blockchain-v3.5/interaction/syncDbWithBlockchain/TransactionLinkFundingsSync.role.ts
@@ -127,32 +127,8 @@ export class TransactionLinkFundingsSyncRole extends AbstractSyncRole<Transactio
     if (!senderKeyPair || !senderPublicKey || !recipientKeyPair || !recipientPublicKey) {
       throw new Error(`missing key for ${this.itemTypeName()}: ${JSON.stringify(item, null, 2)}`)
     }
-    let endDateTime: number = item.validUntil.getTime()
-    
-    if (item.redeemedAt) {
-      endDateTime = item.redeemedAt.getTime() + (1000 * 120)
-    } else if (item.deletedAt) {
-      endDateTime = item.deletedAt.getTime() + (1000 * 120)
-    } else {
-      const duration = new DurationSeconds((endDateTime - item.createdAt.getTime()) / 1000)
-      const blockedAmount = GradidoUnit.fromString(reverseLegacyDecay(new Decimal(item.amount.toString()), duration.getSeconds()).toString())
-      const secondsDiff = calculateEffectiveSeconds(
-        new Decimal(item.holdAvailableAmount.toString()), 
-        new Decimal(blockedAmount.toString())
-      )
-      endDateTime = endDateTime - secondsDiff.toNumber() * 1000
-    }
-    if (endDateTime > item.validUntil.getTime()) {
-      endDateTime = item.validUntil.getTime()
-    }
-    let duration = new DurationSeconds((endDateTime - item.createdAt.getTime()) / 1000)
-    const hourInSeconds = 60 * 60
-    if (duration.getSeconds() < hourInSeconds) {
-      duration = new DurationSeconds(hourInSeconds)
-    }
+    let duration = new DurationSeconds((item.validUntil.getTime() - item.createdAt.getTime()) / 1000)
     let blockedAmount = GradidoUnit.fromString(reverseLegacyDecay(new Decimal(item.amount.toString()), duration.getSeconds()).toString())
-    blockedAmount = blockedAmount.add(GradidoUnit.fromGradidoCent(1))
-    // let blockedAmount = decayedAmount.calculateCompoundInterest(duration.getSeconds())
     let accountBalances: AccountBalances
     try {
       accountBalances = this.calculateBalances(item, blockedAmount, communityContext, senderPublicKey, recipientPublicKey)
@@ -171,11 +147,6 @@ export class TransactionLinkFundingsSyncRole extends AbstractSyncRole<Transactio
         throw e
       }
     }
-    /*
-    const decayedAmount = GradidoUnit.fromString(legacyCalculateDecay(new Decimal(item.amount.toString()), item.createdAt, item.validUntil).toString())
-    const blockedAmount = item.amount.add(item.amount.minus(decayedAmount))
-    */
-
     try {
       addToBlockchain(
         this.buildTransaction(item, blockedAmount, duration, senderKeyPair, recipientKeyPair),
diff --git a/dlt-connector/src/migrations/db-v2.7.0_to_blockchain-v3.5/utils.ts b/dlt-connector/src/migrations/db-v2.7.0_to_blockchain-v3.5/utils.ts
index 1e7d0f0b2..58d7c1133 100644
--- a/dlt-connector/src/migrations/db-v2.7.0_to_blockchain-v3.5/utils.ts
+++ b/dlt-connector/src/migrations/db-v2.7.0_to_blockchain-v3.5/utils.ts
@@ -44,10 +44,6 @@ export function reverseLegacyDecay(result: Decimal, seconds: number): Decimal {
   return result.div(FACTOR.pow(seconds).toString())
 }
 
-export function calculateEffectiveSeconds(holdOriginal: Decimal, holdCorrected: Decimal): Decimal {
-  return holdOriginal.div(holdCorrected).ln().div(FACTOR.ln());
-}
-
 export function legacyCalculateDecay(amount: Decimal, from: Date, to: Date): Decimal {
   const fromMs = from.getTime()
   const toMs = to.getTime()
diff --git a/shared/src/const/index.ts b/shared/src/const/index.ts
index 76990ffc8..e208103ac 100644
--- a/shared/src/const/index.ts
+++ b/shared/src/const/index.ts
@@ -1,4 +1,7 @@
+import Decimal from 'decimal.js-light'
+
 export const DECAY_START_TIME = new Date('2021-05-13T17:46:31Z')
+export const DECAY_FACTOR = new Decimal('0.99999997803504048973201202316767079413460520837376')
 export const SECONDS_PER_YEAR_GREGORIAN_CALENDER = 31556952.0
 export const LOG4JS_BASE_CATEGORY_NAME = 'shared'
 export const REDEEM_JWT_TOKEN_EXPIRATION = '10m'
diff --git a/shared/src/logic/decay.ts b/shared/src/logic/decay.ts
index eec9f0cff..23c37abf2 100644
--- a/shared/src/logic/decay.ts
+++ b/shared/src/logic/decay.ts
@@ -1,6 +1,6 @@
 import { Decimal } from 'decimal.js-light'
 
-import { DECAY_START_TIME, SECONDS_PER_YEAR_GREGORIAN_CALENDER } from '../const'
+import { DECAY_FACTOR, DECAY_START_TIME, SECONDS_PER_YEAR_GREGORIAN_CALENDER } from '../const'
 
 Decimal.set({
   precision: 25,
@@ -16,21 +16,30 @@ export interface Decay {
   duration: number | null
 }
 
+// legacy decay formula
 export function decayFormula(value: Decimal, seconds: number): Decimal {
   // TODO why do we need to convert this here to a string to work properly?
   // chatgpt: We convert to string here to avoid precision loss:
   //          .pow(seconds) can internally round the result, especially for large values of `seconds`.
   //          Using .toString() ensures full precision is preserved in the multiplication.
   return value.mul(
-    new Decimal('0.99999997803504048973201202316767079413460520837376').pow(seconds).toString(),
+    DECAY_FACTOR.pow(seconds).toString(),
   )
 }
 
+// legacy reverse decay formula
+export function reverseLegacyDecay(result: Decimal, seconds: number): Decimal {
+  return result.div(DECAY_FACTOR.pow(seconds).toString())
+}
+
+// fast and more correct decay formula
 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))),
   )
 }
+
+// compound interest formula, the reverse decay formula for decayFormulaFast
 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))),