fix: use corrected invoice total for bank allocation

backend/src/routes/banking.ts

@@ -41,6 +41,60 @@ export default async function bankingRoutes(server: FastifyInstance) {
     const ManualInvoices = aliasedTable(incominginvoices, "manual_invoices")
     const ManualInvoiceVendors = aliasedTable(vendors, "manual_invoice_vendors")
 
+    const useCurrentIncomingInvoiceAmount = async (tenantId: number, allocation: any) => {
+        const invoiceId = Number(allocation.incominginvoice)
+        const statementId = Number(allocation.bankstatement)
+        if (!invoiceId || !statementId) return allocation
+
+        const [[invoice], [statement], invoiceAllocations, statementAllocations] = await Promise.all([
+            server.db.select().from(incominginvoices).where(and(
+                eq(incominginvoices.id, invoiceId),
+                eq(incominginvoices.tenant, tenantId)
+            )).limit(1),
+            server.db.select().from(bankstatements).where(and(
+                eq(bankstatements.id, statementId),
+                eq(bankstatements.tenant, tenantId)
+            )).limit(1),
+            server.db.select({ amount: statementallocations.amount }).from(statementallocations).where(and(
+                eq(statementallocations.incominginvoice, invoiceId),
+                eq(statementallocations.tenant, tenantId),
+                eq(statementallocations.archived, false)
+            )),
+            server.db.select({ amount: statementallocations.amount }).from(statementallocations).where(and(
+                eq(statementallocations.bankstatement, statementId),
+                eq(statementallocations.tenant, tenantId),
+                eq(statementallocations.archived, false)
+            )),
+        ])
+
+        if (!invoice || !statement) return allocation
+
+        const accountTotals = (invoice.accounts as any[] || []).reduce((totals, account) => ({
+            net: totals.net + Number(account.amountNet || 0),
+            tax: totals.tax + Number(account.amountTax || 0),
+        }), { net: 0, tax: 0 })
+        const correctedTax = invoice.taxAmountOverride !== null && invoice.taxAmountOverride !== undefined && invoice.taxAmountOverride !== ""
+            ? Number(invoice.taxAmountOverride)
+            : accountTotals.tax
+        const legacyRemaining = Math.max(0, Math.abs(accountTotals.net + accountTotals.tax)
+            - invoiceAllocations.reduce((sum, item) => sum + Math.abs(Number(item.amount || 0)), 0))
+        const correctedRemaining = Math.max(0, Math.abs(accountTotals.net + correctedTax)
+            - invoiceAllocations.reduce((sum, item) => sum + Math.abs(Number(item.amount || 0)), 0))
+        const statementRemaining = Math.max(0, Math.abs(Number(statement.amount || 0))
+            - statementAllocations.reduce((sum, item) => sum + Math.abs(Number(item.amount || 0)), 0))
+        const requestedAmount = Number(allocation.amount || 0)
+        const legacyAssignment = Math.min(legacyRemaining, statementRemaining)
+
+        // Nur den automatisch vorgeschlagenen Altbetrag ersetzen. Bewusst eingegebene Teilbeträge bleiben erhalten.
+        if (Math.abs(Math.abs(requestedAmount) - legacyAssignment) >= 0.005) return allocation
+
+        const currentAssignment = Math.min(correctedRemaining, statementRemaining)
+        return {
+            ...allocation,
+            amount: Number((Math.sign(requestedAmount || (invoice.expense ? -1 : 1)) * currentAssignment).toFixed(2)),
+        }
+    }
+
     const normalizeManualSide = (payload: any, keys: string[]) =>
         keys.filter((key) => payload[key] !== null && payload[key] !== undefined && payload[key] !== "")
 
@@ -1108,6 +1162,7 @@ export default async function bankingRoutes(server: FastifyInstance) {
             const { data: payload } = req.body as { data: any }
             const prepared = prepareStatementAllocationPayload(payload)
             if (prepared.error) return reply.code(400).send({ error: prepared.error })
+            prepared.data = await useCurrentIncomingInvoiceAmount(req.user.tenant_id, prepared.data)
 
             const inserted = await server.db.insert(statementallocations).values({
                 ...prepared.data,