const express = require('express');
const multer = require('multer');
const path = require('path');
const fs = require('fs');

const app = express();
const port = 3000;

app.use(express.static('public'));

const storage = multer.diskStorage({
    destination: (request, file, callBack) => {
        callBack(null, 'public/uploads/');
    },

    filename: (request, file, callBack) => {
        const name = path.extname(file.originalname);
        const direction = 'public/uploads/';
        let count = 0;

        while (fs.existsSync(`${direction}${count}${name}`)) {
            count++;
        }

        callBack(null, `${count}${name}`);
    },
});


const upload = multer({
    storage: storage,

    limits: { 
        fileSize: 10 * 1024 * 1024
    },

    fileFilter: (request, file, callBack) => {
        const allowedFileExtensions = ['.jpg', '.jpeg', '.png', '.svg'];
        const name = path.extname(file.originalname).toLowerCase();

        if (allowedFileExtensions.includes(name)) {
            return callBack(null, true);
        } 
        else {
            return callBack('ERROR');
        }
    },
});

app.post('/upload', upload.single('image'), (request, response) => {
    response.send('SUCCESSFULLY!');
});

app.listen(port, () => {
    console.log(`SERVER STARTED ON POR ${port}`);
});