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)
+}