feat: new separate frontend and backend folders with fastify as nodejs framework, libreconvert is configured in fastify as route

backend/src/routes/libreconvert.route.ts

@@ -0,0 +1,30 @@
+import { FastifyInstance, FastifyReply, FastifyRequest } from "fastify";
+import * as libre from "libreoffice-convert";
+import { promisify } from "util";
+
+const libreConvertAsync = promisify(libre.convert);
+
+export async function libreConvert(app: FastifyInstance) {
+  app.post("/api/libre-convert", async (request: FastifyRequest, reply: FastifyReply) => {
+    try {
+      const data = await request.file();
+      if (!data) {
+        return reply.status(400).send({ error: "No file uploaded!" });
+      }
+
+      const ext = ".pdf";
+      const format = ext.substring(1);
+      const fileBuffer = await data.toBuffer();
+
+      const pdfBuffer = await libreConvertAsync(fileBuffer, ext, undefined);
+
+      reply
+          .header("Content-Type", "application/" + format)
+          .header("Content-Disposition", "attachment; filename=converted" + ext)
+          .send(pdfBuffer);
+    } catch (error) {
+      console.error("Convert error:", error);
+      reply.status(500).send({ error: "Error while converting!" });
+    }
+  });
+}