// server/serial.js
const { SerialPort } = require('serialport');
const { ReadlineParser } = require('@serialport/parser-readline');

let portInstance = null;
let parser       = null;
let latestPayload = null;
let latestImage = null;

function connectSerial(path) {
    if (portInstance?.isOpen) portInstance.close();

    portInstance = new SerialPort({ path: path, baudRate: 115200 });
    parser = portInstance.pipe(new ReadlineParser({ delimiter: '\n' }));
    parser.on('data', line => {
        if(line.includes("image")){
            if(latestImage != null && !latestImage.endsWith("}"))
                latestImage += line.trim().replace("\n", "");
            else
                latestImage = line.trim().replace("\n", "");
            console.log(latestImage)
        }
        else if (line.includes("text")){
            console.log(latestPayload)
            latestPayload = line.trim();
        }
    });
    portInstance.on('error', console.error);
}

function listSerialPorts() {
    return SerialPort.list();
}

function getLatestPacket() {
    return [latestPayload, latestImage];
}

module.exports = { connectSerial, listSerialPorts, getLatestPacket };