/***********************************************************************************************************************************************************************
 * File Name: taskUpload.middleware.js
 * Type of Program: Middleware
 * Description: Multer config for task completion file uploads.
 *              Uses memory storage — buffer is passed directly to S3.
 *              Single file per request (matches the two-step upload flow in
 *              ViewTaskDetails where each file is uploaded individually).
 *
 * Limits:
 *   fileSize: 500 MB (matches FileUpload.jsx DEFAULT_MAX_BYTES)
 *
 * Author: rgrgogu
 * Date Created: Jun. 13, 2026
 ***********************************************************************************************************************************************************************/
const multer = require('multer');

const storage = multer.memoryStorage();

const upload = multer({
    storage,
    limits: {
        fileSize: 500 * 1024 * 1024, // 500 MB
    },
});

// Single file per request — field name must be "file"
const uploadTaskFile = upload.single('file');

// ─── Error wrapper ────────────────────────────────────────────────────────────
// Converts multer errors to a consistent R.error-style response.
const handleUpload = (req, res, next) => {
    uploadTaskFile(req, res, (err) => {
        if (!err) return next();

        if (err.code === 'LIMIT_FILE_SIZE') {
            return res.status(400).json({
                status: 'error',
                message: 'File exceeds the 500 MB size limit.',
            });
        }

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

module.exports = { handleUpload };