const express = require('express');
const app = express();

const UDP = require('dgram')

const client = UDP.createSocket('udp4')

const port = 52381

const hostname = '192.168.0.152'

app.listen(8080, () => {
	console.log('Server running on port 8080');
	require('child_process').exec("start http://localhost:8080");
});

app.use(express.static('public'));
app.use(express.json());

const fs = require('fs');

let playlist = JSON.parse(fs.readFileSync('playlist.json', 'utf8'));

app.post("/playlist", (req, res) => {
	playlist = req.body;
	fs.writeFileSync('playlist.json', JSON.stringify(playlist));
	res.sendStatus(200);
});

app.get("/playlist", (req, res) => {
	res.json(playlist);
});

app.post("/setpos", (req, res) => {
	setPos(req.body.x, req.body.y, req.body.zoom, req.body.vs, req.body.hs);
	res.sendStatus(200);
});

app.post("/run", (req, res) => {
	run();
	res.sendStatus(200);
});

function setPos(x, y, zoom, vs = 18, hs = 14) {
	const packet = Buffer.from("01 00 00 09 00 00 00 00 81 01 06 02 12 0e 00 00 00 00 00 00 00 00 ff".replaceAll(" ", ""), "hex");

	x1 = x & 0xf
	x2 = (x >> 4) & 0xf
	x3 = (x >> 8) & 0xf
	x4 = (x >> 12) & 0xf
	y1 = y & 0xf
	y2 = (y >> 4) & 0xf
	y3 = (y >> 8) & 0xf
	y4 = (y >> 12) & 0xf
	packet[14] = x4
	packet[15] = x3
	packet[16] = x2
	packet[17] = x1
	packet[18] = y4
	packet[19] = y3
	packet[20] = y2
	packet[21] = y1

	packet[12] = vs
	packet[13] = hs

	client.send(packet, port, hostname, (err) => {
		if (err) {
			console.error('Failed to send packet !!')
		}
	})

	const zoomPacket = Buffer.from("01 00 00 09 00 00 00 00 81 01 04 47 00 00 00 00 FF".replaceAll(" ", ""), "hex");

	z1 = zoom & 0xf
	z2 = (zoom >> 4) & 0xf
	z3 = (zoom >> 8) & 0xf
	z4 = (zoom >> 12) & 0xf
	zoomPacket[12] = z4
	zoomPacket[13] = z3
	zoomPacket[14] = z2
	zoomPacket[15] = z1

	client.send(zoomPacket, port, hostname, (err) => {
		if (err) {
			console.error('Failed to send packet !!')
		}
	})
}

function run() {
	let delaySum = 0;
	for (let i = 0; i < playlist.length; i++) {

		setTimeout(() => {
			setPos(playlist[i].x, playlist[i].y, playlist[i].zoom, playlist[i].vs, playlist[i].hs)
		}, delaySum);
		delaySum += playlist[i].delay;
	}
}