Implemented attachment file download function

backend/routes/attachments/download.js

@@ -0,0 +1,34 @@
+const express = require("express");
+const router = express.Router();
+const path = require("path");
+const fs = require("fs");
+const defineAttachment = require("../../models/attachments");
+const { DataTypes } = require("sequelize");
+
+module.exports = function (sequelize) {
+  const Attachment = defineAttachment(sequelize, DataTypes);
+  router.get("/download/:attachmentId", async (req, res) => {
+    const attachmentId = req.params.attachmentId;
+
+    try {
+      const attachment = await Attachment.findByPk(attachmentId);
+      if (!attachment) {
+        return res.status(404).send("Attachment not found");
+      }
+
+      const filename = attachment.path.split("/").pop();
+      const filePath = path.join(__dirname, `../../public/uploads/${filename}`);
+
+      if (!fs.existsSync(filePath)) {
+        return res.status(404).json({ error: "File not found" });
+      }
+
+      res.download(filePath);
+    } catch (error) {
+      console.error(error);
+      res.status(500).send("Internal Server Error");
+    }
+  });
+
+  return router;
+};