index.js

var express = require("express")
var app = express()
var fs = require("fs")
var upload = require("express-fileupload")
app.use(express.json());
app.use(upload())

var requestName
var filename
var requestStatus = false

app.listen(3000, () => console.log("server on port 3000"))

app.get("/", (req, res) => {
    res.sendfile("index.html")
})

app.post("/name", (req,res) => {
    filename = `./downloads/${req.body.input}.jpg`
    console.log(filename)
    console.log()
    fs.exists(filename, (exists) => {
        requestStatus = exists
       // console.log("file:"+requestName, exists ? " exists" : "not existing")
    })
})

app.get("/download", (req, res) => {
    console.log(requestName)
        if(!requestStatus){
            res.send("404 du affe")
            console.log("404")
            requestName = ""
        }
        else{
            res.download(__dirname + `/downloads/${requestName}.jpg`, `${requestName}`)
            console.log(filename)
            }
})

app.post("/upload", (req,res) => {
    console.error("user data:")
    console.log("   ",req.headers['user-agent'], "\n   ",req.connection.remoteAddress)
    if(req.files){
        var file = req.files.foo,
            filename = file.name
        file.mv("./downloads/"+filename,(err) => {
            console.error(err)
        })
        console.log(filename)
    }
   // res.send("success hope you get redirected)"
   res.redirect("/",301)
})

app.get("/all", (req,res) => {
    fs.readdir(__dirname + "/downloads/", (err,files) => {
        var data = {
            fileData : files 
        }
        res.json(data)
    })
})