From 54b8ddb55bb55b8b67d3dfe0aa1adafc57b1dfd6 Mon Sep 17 00:00:00 2001
From: David Mellen <d.mellen@posteo.de>
Date: Mon, 6 Oct 2025 11:09:50 +0200
Subject: [PATCH] Fix split input locale decimal seperator

---
 src/components/AddExpense/SplitTypeSection.tsx |  4 ++--
 src/utils/numbers.ts                           | 16 ++++++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/components/AddExpense/SplitTypeSection.tsx b/src/components/AddExpense/SplitTypeSection.tsx
index 183f6785..f566476f 100644
--- a/src/components/AddExpense/SplitTypeSection.tsx
+++ b/src/components/AddExpense/SplitTypeSection.tsx
@@ -14,7 +14,7 @@ import { type ChangeEvent, useCallback, useMemo } from 'react';
 import { useTranslationWithUtils } from '~/hooks/useTranslationWithUtils';
 
 import { type AddExpenseState, type Participant, useAddExpenseStore } from '~/store/addStore';
-import { removeTrailingZeros, toSafeBigInt, toUIString } from '~/utils/numbers';
+import { removeTrailingZeros, toSafeBigInt, toUINumber, toUIString } from '~/utils/numbers';
 
 import { type TFunction, useTranslation } from 'next-i18next';
 import { EntityAvatar } from '../ui/avatar';
@@ -205,7 +205,7 @@ const getSplitProps = (t: TFunction): SplitSectionProps[] => [
       );
       return `${t('expense_details.add_expense_details.split_type_section.types.exact.remaining')} ${currency} ${toUIString(amount - totalAmount, true)}`;
     },
-    fmtShareText: (share) => removeTrailingZeros(toUIString(share)),
+    fmtShareText: (share) => removeTrailingZeros(toUINumber(share).toString()),
     step: null,
   },
   {
diff --git a/src/utils/numbers.ts b/src/utils/numbers.ts
index da0d3e7a..2992309f 100644
--- a/src/utils/numbers.ts
+++ b/src/utils/numbers.ts
@@ -22,6 +22,22 @@ export function toSafeBigInt(num: number | string) {
   }
 }
 
+export function toUINumber(num = 0n, currencyCode: CurrencyCode = 'USD') {
+  const { decimalDigits } = CURRENCIES[currencyCode];
+  const maxDecimals = 10n ** BigInt(decimalDigits);
+  const decimalPart = num % 100n;
+  const wholePart = Number(BigMath.abs(num) / 100n);
+
+  let result = Number(wholePart);
+
+  if (decimalPart !== 0n) {
+    const frac = Number(decimalPart) / Number(maxDecimals);
+    result += frac;
+  }
+
+  return result;
+}
+
 export function toUIString(num = 0n, signed = false, currencyCode: CurrencyCode = 'USD') {
   const { decimalDigits } = CURRENCIES[currencyCode];
   const maxDecimals = 10n ** BigInt(decimalDigits);