server.js

const express = require('express')
require('dotenv').config()
const randomstring = require("randomstring");
const fs = require('fs');
const app = express()
const port = process.env.PORT || 3000;

app.use(express.json());

let data = []
let sharedKey

//Create a Shared Key
if (!process.env.SHARED_KEY) {
    sharedKey = randomstring.generate()
    fs.writeFile('.env', `SHARED_KEY=${sharedKey}`, function (err) {
        if (err) return console.log(err);
        console.log(`Shared Key set: ${sharedKey}\nDelete .env file to generate a new key.`)
    })
} else {
    sharedKey = process.env.SHARED_KEY
    console.log(`Shared Key: ${sharedKey}\nDelete .env file to generate a new key.`)
}

app.use(function (req, res, next) {
    if (!req.headers.authorization) {
        return res.status(401).json({
            error: 'No credentials sent!'
        });
    }
    if (req.headers.authorization != sharedKey) {
        return res.status(401).json({
            error: 'Wrong credentials'
        });
    }
    next();
});

//Gives Location Data
app.get('/', (req, res) => {
    let timestamp = Date.now()

    checkData(timestamp)
    
    res.send(data)
})

//Receives Location Data
app.post('/post', (req, res) => {
    let newObj = req.body
    let timestamp = Date.now()

    updateData(newObj, timestamp)
    checkData(timestamp)
    res.send(data)
})

//Updates Location Data
function updateData(newObj, timestamp) {
    let objectAlreadyExisted = false
    data.forEach(d => {
        if (d.name == newObj.name) {
            objectAlreadyExisted = true
            d.name = newObj.name
            d.x = newObj.waypoint.x
            d.y = newObj.waypoint.y
            d.plane = newObj.waypoint.plane
            d.type = newObj.type
            d.title = newObj.title
            d.world = newObj.world
            d.timestamp = timestamp;
        }
    });

    if (!objectAlreadyExisted) data.push({
        "name": newObj.name,
        "x": newObj.waypoint.x,
        "y": newObj.waypoint.y,
        "plane": newObj.waypoint.plane,
        "type": newObj.type,
        "title": newObj.title,
        "world": newObj.world,
        "timestamp": timestamp,
    })
}

//Checks if it has received data from a user for the last 5 seconds
function checkData(timestamp) {
    for (let i = data.length - 1; i >= 0; i--) {
        if (timestamp - data[i].timestamp > 5000) {
            data.splice(i)
        }
    }
}

app.listen(port, () => {
    console.log(`Example app listening at http://localhost:${port}`)
})