server/upload.js

// backend/upload.js
const path = require('path');
const multer = require('multer');
const fs = require('fs');

// Ensure uploads folder exists
const uploadsDir = path.join(__dirname, 'uploads');
if (!fs.existsSync(uploadsDir)) {
  fs.mkdirSync(uploadsDir, { recursive: true });
}

const upload = multer({
  dest: uploadsDir, // Absolute path to uploads folder
  limits: { fileSize: 15 * 1024 * 1024 }, // 15MB max
  fileFilter: (req, file, cb) => {
    const allowedTypes = [
      'application/pdf',
      'application/msword',
      'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
      'text/plain'
    ];
    if (allowedTypes.includes(file.mimetype)) {
      cb(null, true);
    } else {
      cb(new Error('Invalid file type. Only PDF, Word, and TXT files are allowed.'));
    }
  }
});

module.exports = upload;