// client.mjs
import net from 'node:net';

const HOST = '192.168.2.25';   // <-- set Pico IP
const PORT = 5505;

function buildFrame(cmd, payload) {
	const len = payload.length;
	const frame = Buffer.alloc(3 + len);

	frame[0] = cmd;
	frame[1] = len & 0xff;        // len_lo
	frame[2] = (len >> 8) & 0xff; // len_hi
	payload.copy(frame, 3);

	return frame;
}

function parseFrame(buffer) {
	if (buffer.length < 3) {
		return null;
	}

	const cmd = buffer[0];
	const len = buffer[1] | (buffer[2] << 8);

	if (buffer.length < 3 + len) {
		return null;
	}

	const payload = buffer.subarray(3, 3 + len);
	return { cmd, payload };
}

const socket = net.createConnection({ host: HOST, port: PORT });

let rxBuffer = Buffer.alloc(0);

socket.on('connect', () => {
	const payload = Buffer.from('Test');
	const frame = buildFrame(0x10, payload);
	socket.write(frame);
});

socket.on('data', (chunk) => {
	rxBuffer = Buffer.concat([rxBuffer, chunk]);

	const frame = parseFrame(rxBuffer);
	if (frame) {
		console.log('CMD:', frame.cmd);
		console.log('Payload:', frame.payload.toString());
		socket.end();
	}
});

socket.on('error', (err) => {
	console.error(err);
});