var {WebSocketServer} = require("ws");
var qs = require("qs");
var proxyaddr = require("proxy-addr");
var child_process = require("child_process");
var {app, server} = require("./web");
var {getList, uncacheList} = require("./metalist");
var fs = require("fs");

var wss = new WebSocketServer({ server });

wss.on("connection", function(ws, req) {
	req.ip = proxyaddr(req, app.get("trust proxy"));
	req.query = qs.parse(req.url.substring(req.url.indexOf('?')+1));

	var log = (msg, e) => console[e?'error':'log'](`[${new Date().toLocaleString()}] ${req.ip} - ${msg}`);
	log("socket open: " + req.url);

	var yturl = req.query.url;
	if (!yturl) { ws.send(color("red", "missing url")); ws.close(); return }

	var alias = req.query.alias;
	if (alias) {
		alias = alias.toLowerCase();
		if (!/^[a-z0-9-_]{1,32}$/.test(alias)) { ws.send(color("red", "alias must be no more than 32 chars of only letters, numbers, hypens or underscores.")); ws.close(); return }
		if (fs.existsSync(`aliases/${alias}`)) { ws.send(color("red", `the alias ${alias} already exists.`)); ws.close(); return }
	}

	var ytid = yturl.match(/https:\/\/(?:(?:www\.)?youtube\.com\/(?:watch\?v=|shorts\/)|youtu\.be\/)([A-Za-z0-9_-]{11})/)?.[1];
	if (!ytid) { ws.send(color("red", "youtube url not valid")); ws.close(); return }

	ws.send(color("green", "spawning yt-dlp..."));
	var cp = child_process.spawn("yt-dlp", ["--format=mp4", "--max-filesize=1G", `--match-filter=duration<7200`, "--no-mtime", `https://www.youtube.com/watch?v=${ytid}`], {cwd: "videos", shell: false});

	cp.on("error", error => {
		log(error.message, true);
		ws.send(color("red", error.message));
	});
	cp.stdout.on("data", data => {
		var msg = data.toString().trim();
		if (msg) {
			log(msg);
			ws.send("yt-dlp: " + color("blue", msg));
		}
	});
	cp.stderr.on("data", data => {
		var msg = data.toString().trim();
		if (msg) {
			log(msg, true);
			ws.send(color("orange", "yt-dlp: " + color("blue", msg)));
		}
	});
	cp.on("close", (code, signal) => {
		log(`cp exit ${code} (${signal})`);
		ws.send(color("green", `yt-dlp exited with code ${code}`));
		let files = fs.readdirSync("videos");
		let file = files.find(file => file.includes(`[${ytid}]`));
		if (file) {
			if (alias) fs.writeFileSync(`aliases/${alias}`, file);
			let url = `https://${req.headers.host}/v/${file}`;
			ws.send(`MP4 URL (<button onclick="navigator.clipboard.writeText(\`${url}\`)">Copy</button>): <a href="${url}">${url}</a>`)
		} else {
			ws.send(color("red", "error: couldn't find file to alias"));
		}
		
		uncacheList();
		ws.close();
	});

	ws.on("close", () => {
		log("socket closed");
		cp.kill();
	});
});

function color(color, text) {
	return `<span style="color: ${color}">${text}</span>`;
}