fix: removed bad error handling structure, using good error handling like video-to-audio route with tmp files

backend/src/routes/removebg.route.ts

@@ -1,13 +1,21 @@
 import { FastifyInstance, FastifyReply, FastifyRequest } from "fastify";
-import { removeBackground } from "@imgly/background-removal-node";
-import sharp from "sharp";
+import { promises as fs } from "fs";
+import * as path from "path";
+import { randomUUID } from "crypto";
+import { spawn } from "child_process";
 
 export async function removeBG(app: FastifyInstance) {
   app.post(
     "/api/remove-bg",
     async (request: FastifyRequest, reply: FastifyReply) => {
+      const tmpDir = path.join(process.cwd(), "tmp");
+      const sessionId = randomUUID();
+      const inputPath = path.join(tmpDir, `input-${sessionId}.png`);
+      const outputPath = path.join(tmpDir, `output-${sessionId}.png`);
+
       try {
         const parts = request.parts();
+        await fs.mkdir(tmpDir, { recursive: true });
 
         let fileBuffer: Buffer | null = null;
 
@@ -21,20 +29,47 @@ export async function removeBG(app: FastifyInstance) {
           return reply.status(400).send({ error: "No file uploaded!" });
         }
 
+        await fs.writeFile(inputPath, fileBuffer);
         console.log("Received file, buffer length:", fileBuffer.length);
 
-        const rightFileBuffer = await sharp(fileBuffer)
-          .toFormat("png")
-          .toBuffer();
-        console.log("Converted file:", rightFileBuffer);
-        const convertedBuffer = await removeBackground(rightFileBuffer);
+        await new Promise<void>((resolve, reject) => {
+          const pythonProcess = spawn("rembg", ["i", inputPath, outputPath]);
+
+          pythonProcess.stderr.on("data", (data) => {
+            console.log(`ffmpeg stderr: ${data}`);
+          });
+
+          pythonProcess.on("close", (code) => {
+            if (code === 0) {
+              resolve();
+            } else {
+              reject(new Error(`rembg process exited with code ${code}`));
+            }
+          });
+
+          pythonProcess.on("error", (err) => {
+            reject(err);
+          });
+        });
+
+        const outputImageBuffer = await fs.readFile(outputPath);
+        await Promise.all([fs.unlink(inputPath), fs.unlink(outputPath)]);
 
         reply
           .header("Content-Type", "image/png")
           .header("Content-Disposition", `attachment; filename="converted.png"`)
           .status(200)
-          .send(convertedBuffer);
+          .send(outputImageBuffer);
       } catch (error) {
+        try {
+          await Promise.all([
+            fs.unlink(inputPath).catch(() => {}),
+            fs.unlink(outputPath).catch(() => {}),
+          ]);
+        } catch (cleanupError) {
+          console.error("Cleanup error:", cleanupError);
+        }
+
         console.error("Convert error:", error);
         reply.status(500).send({ error: "Error while converting!" });
       }