index.js

const express = require('express');
const http = require('http');
const path = require('path');
const ip = require('ip');
const app = express();
const server = http.createServer(app);
const fs = require('fs')
const bodyParser = require('body-parser');

app.use(express.static(path.join(__dirname, 'public')));
app.use(express.json({limit: '100mb'})); // Use express.json() to parse JSON bodies
app.use(bodyParser.json({ limit: '5mb' })); // Set maximum payload size to 5 MB
app.use(bodyParser.urlencoded({ extended: true, limit: '5mb' }));


 // Use body-parser to parse plain text request bodies

const connectedDevices = {};
let serverReady = false;
let serverConfig = {
    NumberOfMeasurements: null,
    Intervals: null,
    Delay: null,
};

app.get('/', (req, res) => {
    res.sendFile(path.join(__dirname, 'index.html'));
});
app.get('/list', (req, res) => {
    res.sendFile(path.join(__dirname, 'list.html'));
});

// Add route to get server info
app.get('/server-info', (req, res) => {
    const serverInfo = {
        ip: ip.address(),
        port: PORT,
    };
    res.json(serverInfo);
});

// POST route for handling "init" messages
app.post('/init', (req, res) => {
    console.log(`Received "init" message`);
    //If the measurement parameters has not been set yet
    if (!serverReady) {
        const responseToSend = { error: 'ServerNotReady' };
        console.log('Sent JSON:', responseToSend);
        return res.status(503).json(responseToSend);
    }

    try {
        const deviceID = generateDeviceID();
        // Store device-specific information
        connectedDevices[deviceID] = {
            state: 'Init',
            current_cnt: 0
        };
        const responseToSend = { error:'',deviceID, serverConfig };
        console.log('Sending response:', responseToSend);

        // Send the device ID and configuration back to the client
        res.json(responseToSend);
    } catch (error) {
        console.log(error.message);
        res.status(400).json({ error: error.message });
    }
});


// POST route for checking "am-i-ok" messages
app.post('/am-i-ok/:deviceID', (req, res) => {
    const deviceID = req.params.deviceID;
    let responseToSend
    // Check if the device is registered
    if (connectedDevices.hasOwnProperty(deviceID)) {
        console.log(`Received "am-i-ok" message from device ${deviceID}`);

        // Update the device state to "Ready"
        connectedDevices[deviceID].state = 'Id confirmed';
        responseToSend = { error: '' }
        return res.status(200).json(responseToSend);

    } else {
        responseToSend = { error: 'NotOK' }
        return res.status(501).json(responseToSend);
    }
    console.log('Sent JSON:', responseToSend);
});

app.post('/json/:deviceID/:f_n', (req, res) => {
    const deviceID = req.params.deviceID;
    const f_n = req.params.f_n;
    console.log(`Json incoming form: ${deviceID}`)
    console.log(`Json incoming form: ${f_n}`)
    let responseToSend

    const measurementsFolderPath = path.join(__dirname, 'measurements', deviceID);

    // Check if the folder exists, if not create it
    if (!fs.existsSync(measurementsFolderPath)) {
        fs.mkdirSync(measurementsFolderPath, { recursive: true });
    }

    // Get filename from request body
    console.log("The body of the request is:")
    console.log(req.body)
    console.log("The parameters are:")
    console.log(req.params)
    const { filename, ...jsonData } = req.body;
    console.log(`The filename should be: ${filename}`)

    // Generate unique filename if not provided
    const fileName = f_n + '.json' || deviceID + '.json';

    // Path to save the file
    const filePath = path.join(measurementsFolderPath, fileName);

    // Write JSON data to the file



    fs.writeFile(filePath, JSON.stringify(jsonData, null, 2), (err) => {
        if (err) {
            console.error('Error saving file:', err);
            responseToSend = { error: err }
            return res.status(500).json(responseToSend);
        } else {
            console.log('File saved successfully:', filePath);
            responseToSend = { error: '' }
            return res.status(200).json(responseToSend);
        }
    });

    console.log('Sent JSON:', responseToSend);
});


app.post('/ready/:deviceID', (req, res) => {
    const deviceID = req.params.deviceID;
    let responseToSend
    // Check if the device is registered
    if (connectedDevices.hasOwnProperty(deviceID)) {
        console.log(`Received "ready" message from device ${deviceID}`);
        // Update the device state to "Ready"
        connectedDevices[deviceID].state = 'Ready';
    }
});

app.post('/stillHere/:deviceID', (req, res) => {
    const deviceID = req.params.deviceID;
    // Check if the device is registered
    if (connectedDevices.hasOwnProperty(deviceID)) {
        console.log(`Received "stillHere" message from device ${deviceID}`);

        // Increment the current count for the device
        connectedDevices[deviceID].current_cnt = (connectedDevices[deviceID].current_cnt || 0) + 1;

        // Prepare the response with the updated current count
        const responseToSend = {
            error: '',
            current_cnt: connectedDevices[deviceID].current_cnt,
        };

        console.log('Sent JSON:', responseToSend);
        return res.status(200).json(responseToSend);
    } else {
        const responseToSend = { error: 'DeviceNotRegistered' };
        console.log('Sent JSON:', responseToSend);
        return res.status(404).json(responseToSend);
    }
});


function generateDeviceID() {
    // Generate a unique device ID (you can use a more robust method if needed)
    return Date.now().toString(36) + Math.random().toString(36).substr(2, 5);
}

app.get('/get-devices', (req, res) => {
    const devicesList = Object.keys(connectedDevices).map(deviceID => {
        return {
            id: deviceID,
            state: connectedDevices[deviceID].state,
            current_cnt: connectedDevices[deviceID].current_cnt
        };
    });

    res.json(devicesList);
});
app.post('/set-server-config', (req, res) => {
    // Handle the POST request to set server configuration
    const { NumberOfMeasurements, Intervals, Delay } = req.body;

    // Update the server configuration as needed
    serverConfig = {
        NumberOfMeasurements,
        Intervals,
        Delay,
    };

    res.send('Server configuration set: ');
    serverReady = true
});

const PORT = 3000;
server.listen(PORT, () => {
    console.log(`Server is running on http://${ip.address()}:${PORT}`);
});