const multer = require('multer');
const path = require('path');
const { v4: uuidv4 } = require('uuid');

// Configure storage
const storage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, 'uploads/');
  },
  filename: (req, file, cb) => {
    const uniqueName = `${uuidv4()}${path.extname(file.originalname)}`;
    cb(null, uniqueName);
  }
});

// File filter
const fileFilter = (req, file, cb) => {
  const allowedTypes = {
    'image/jpeg': true,
    'image/jpg': true,
    'image/png': true,
    'image/gif': true,
    'image/webp': true,
    'audio/mpeg': true,
    'audio/wav': true,
    'audio/ogg': true,
    'audio/mp4': true,
    'application/pdf': true,
    'text/plain': true,
    'text/markdown': true
  };

  if (allowedTypes[file.mimetype]) {
    cb(null, true);
  } else {
    cb(new Error(`File type ${file.mimetype} is not supported`), false);
  }
};

const upload = multer({
  storage,
  fileFilter,
  limits: {
    fileSize: 50 * 1024 * 1024 // 50MB max file size
  }
});

// Error handling middleware for multer
const handleUploadError = (error, req, res, next) => {
  if (error instanceof multer.MulterError) {
    if (error.code === 'LIMIT_FILE_SIZE') {
      return res.status(400).json({ error: 'File too large. Maximum size is 50MB.' });
    }
    return res.status(400).json({ error: `Upload error: ${error.message}` });
  }
  
  if (error) {
    return res.status(400).json({ error: error.message });
  }
  
  next();
};

module.exports = { upload, handleUploadError };