Kundeninventar-Nummern kollisionsfrei vergeben

backend/src/routes/resources/main.ts

@@ -1035,7 +1035,25 @@ export default async function resourceRoutes(server: FastifyInstance) {
 
             if (config.numberRangeHolder && !body[config.numberRangeHolder]) {
                 const numberRangeResource = resource === "members" ? "customers" : resource
-                const result = await useNextNumberRangeNumber(server, req.user.tenant_id, numberRangeResource)
+                const numberRangeColumn = table[config.numberRangeHolder]
+                const tenantColumn = getTenantColumn(resource, table)
+                const result = await useNextNumberRangeNumber(
+                    server,
+                    req.user.tenant_id,
+                    numberRangeResource,
+                    async (candidate, tx) => {
+                        const existing = await tx
+                            .select({ id: table.id })
+                            .from(table)
+                            .where(and(
+                                eq(tenantColumn, req.user!.tenant_id),
+                                eq(numberRangeColumn, candidate)
+                            ))
+                            .limit(1)
+
+                        return existing.length === 0
+                    }
+                )
                 createData[config.numberRangeHolder] = result.usedNumber
             }
 

backend/src/utils/functions.ts

@@ -10,7 +10,8 @@ import { eq, sql } from "drizzle-orm"
 export const useNextNumberRangeNumber = async (
     server: FastifyInstance,
     tenantId: number,
-    numberRange: string
+    numberRange: string,
+    isAvailable: (candidate: string, tx: any) => Promise<boolean> = async () => true
 ) => {
     const numberRangeFallbacks: Record<string, string> = {
         costEstimates: "quotes",
@@ -44,18 +45,39 @@ export const useNextNumberRangeNumber = async (
         }
 
         const current = numberRanges[resolvedNumberRange]
+        let nextNumber = Number(current.nextNumber)
 
-        const usedNumber =
-            (current.prefix || "") +
-            current.nextNumber +
-            (current.suffix || "")
+        if (!Number.isFinite(nextNumber)) {
+            throw new Error(`Number range '${resolvedNumberRange}' has an invalid nextNumber`)
+        }
+
+        let usedNumber = ""
+        const maxAttempts = 10000
+
+        for (let attempt = 0; attempt < maxAttempts; attempt++) {
+            const candidate =
+                (current.prefix || "") +
+                nextNumber +
+                (current.suffix || "")
+
+            if (await isAvailable(candidate, tx)) {
+                usedNumber = candidate
+                break
+            }
+
+            nextNumber++
+        }
+
+        if (!usedNumber) {
+            throw new Error(`Could not find an available number in range '${resolvedNumberRange}'`)
+        }
 
         const updatedRanges = {
             // @ts-ignore
             ...numberRanges,
             [resolvedNumberRange]: {
                 ...current,
-                nextNumber: current.nextNumber + 1,
+                nextNumber: nextNumber + 1,
             },
         }