let params;
let cur_seconds = null;
let timer_id;
const cd = document.getElementById("countdown");

function setupCountdown() {
	params = new URLSearchParams(document.location.search);
	for ([key, value] of params.entries()) {
		console.log(`${key}: ${value}`);
	}

	cur_seconds = parseInt(params.get("duration"));

	if (params.get("f_family") !== "") {
		cd.style.fontFamily = params.get("f_family");
	}
	cd.style.color = params.get("f_color");

	draw();
	timer_id = window.setInterval(tick, 1000);
}

function tick() {
	if (cur_seconds == 0) {
		while (cd.firstChild) {
			cd.removeChild(cd.firstChild);
		}
		let end_msg = document.createElement("div");
		end_msg.textContent = params.get("end_text");
		cd.appendChild(end_msg);
		window.clearInterval(timer_id);
		return;
	}
	cur_seconds--;
	draw();
}

function draw() {
	document.getElementById("minutes").textContent = zero_pad(Math.floor(cur_seconds / 60));
	document.getElementById("seconds").textContent = zero_pad((cur_seconds % 60));
}

function zero_pad(num) {
	if (num < 10) {
		return "0"+num;
	} else {
		return num;
	}
}