/***********************************************************************************************************************************************************************
 * File Name: avatar_upload.middleware.js
 * Type of Program: Middleware
 * Description: Multer config for avatar uploads.
 *              Memory storage — buffer is passed directly to S3.
 *              Accepts JPEG, PNG, WebP, GIF only. 5 MB limit.
 *
 * Author: Kenneth Obsequio (@lash0000)
 * Date Created: Jun. 18, 2026
 ***********************************************************************************************************************************************************************/
'use strict';

const multer = require('multer');

const ALLOWED_MIME = new Set(['image/jpeg', 'image/png', 'image/webp', 'image/gif']);

const upload = multer({
  storage: multer.memoryStorage(),
  limits: { fileSize: 5 * 1024 * 1024 }, // 5 MB
  fileFilter(req, file, cb) {
    if (ALLOWED_MIME.has(file.mimetype)) return cb(null, true);
    cb(Object.assign(new Error('Only JPEG, PNG, WebP, or GIF images are allowed.'), { code: 'INVALID_TYPE' }));
  },
});

const avatarSingle = upload.single('avatar');

// Wraps multer errors into the project's standard error shape.
const handleAvatarUpload = (req, res, next) => {
  avatarSingle(req, res, (err) => {
    if (!err) return next();

    if (err.code === 'LIMIT_FILE_SIZE') {
      return res.status(400).json({ status: 'error', message: 'Avatar must be under 5 MB.' });
    }
    if (err.code === 'INVALID_TYPE') {
      return res.status(400).json({ status: 'error', message: err.message });
    }

    console.error('[MULTER AVATAR]', err);
    return res.status(400).json({ status: 'error', message: err.message ?? 'Upload failed.' });
  });
};

module.exports = { handleAvatarUpload };