KI-AGENT: ZUGFeRD- und E-Rechnungserkennung ergänzen

backend/src/utils/fileBuffer.ts

@@ -0,0 +1,26 @@
+import { GetObjectCommand } from "@aws-sdk/client-s3"
+import { s3 } from "./s3"
+import { secrets } from "./secrets"
+
+export const streamToBuffer = async (stream: any): Promise<Buffer> => {
+    const chunks: Buffer[] = []
+
+    for await (const chunk of stream) {
+        chunks.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk))
+    }
+
+    return Buffer.concat(chunks)
+}
+
+export const loadFileBuffer = async (path: string): Promise<Buffer> => {
+    const response = await s3.send(new GetObjectCommand({
+        Bucket: secrets.S3_BUCKET,
+        Key: path,
+    }))
+
+    if (!response.Body) {
+        throw new Error(`S3-Datei '${path}' enthält keinen lesbaren Inhalt.`)
+    }
+
+    return streamToBuffer(response.Body)
+}

backend/src/utils/gpt.ts

@@ -2,12 +2,11 @@ import dayjs from "dayjs";
 import OpenAI from "openai";
 import { z } from "zod";
 import { zodResponseFormat } from "openai/helpers/zod";
-import { GetObjectCommand } from "@aws-sdk/client-s3";
 import { FastifyInstance } from "fastify";
 
-import { s3 } from "./s3";
-import { secrets } from "./secrets";
 import { storeExtractedTextForFile } from "./documentText";
+import { loadFileBuffer } from "./fileBuffer";
+import { secrets } from "./secrets";
 
 // Drizzle schema
 import { vendors, accounts, tenants } from "../../db/schema";
@@ -27,18 +26,6 @@ export const initOpenAi = async () => {
     });
 };
 
-// ---------------------------------------------------------
-// STREAM → BUFFER
-// ---------------------------------------------------------
-async function streamToBuffer(stream: any): Promise<Buffer> {
-    return new Promise((resolve, reject) => {
-        const chunks: Buffer[] = [];
-        stream.on("data", (chunk: Buffer) => chunks.push(chunk));
-        stream.on("error", reject);
-        stream.on("end", () => resolve(Buffer.concat(chunks)));
-    });
-}
-
 // ---------------------------------------------------------
 // GPT RESPONSE FORMAT (Zod Schema)
 // ---------------------------------------------------------
@@ -93,7 +80,8 @@ const InstructionFormat = z.object({
 export const getInvoiceDataFromGPT = async function (
     server: FastifyInstance,
     file: any,
-    tenantId: number
+    tenantId: number,
+    suppliedFileData?: Buffer,
 ) {
     await initOpenAi();
 
@@ -109,13 +97,7 @@ export const getInvoiceDataFromGPT = async function (
     let fileData: Buffer;
 
     try {
-        const command = new GetObjectCommand({
-            Bucket: secrets.S3_BUCKET,
-            Key: file.path,
-        });
-
-        const response: any = await s3.send(command);
-        fileData = await streamToBuffer(response.Body);
+        fileData = suppliedFileData || await loadFileBuffer(file.path);
     } catch (err) {
         console.log(`❌ S3 Download failed for file ${file.id}`, err);
         return null;