"use strict";

function $(name) { return document.getElementById(name); }

function Tag(name, attrs, body, children, eventName, eventHandler) {
	let elem = document.createElement(name);
	if (body) {
		// elem.innerHTML = body; // innerHTML is ugly (slow, overwrite childNodes) 
		let textNode = document.createTextNode(body);
		elem.appendChild(textNode);
	}
	for (let k in attrs) {
		elem.setAttribute(k, attrs[k]);
	}
	for (let i in children) {
		elem.appendChild(children[i]);
	}

	if (eventName && eventHandler) {
		elem.addEventListener(eventName, eventHandler);
	}

	return elem;
}

function Text(text) {
	return document.createTextNode(text);
}

function debounce(func, cancelFunc = ()=>{}, timeout = 500) {
	let timer;
	return (...args) => {
		cancelFunc();
		clearTimeout(timer);
		timer = setTimeout(() => { func.apply(this, args); }, timeout);
	}
}

function sendRequest(method, path, query, body, funcDone, funcError) {
	let req = new XMLHttpRequest();
	if (query) {
		let params = new URLSearchParams(query);
		path = path + "?" + params.toString();
	}
	req.open(method, path, true);
	req.onreadystatechange = function () {
		if (req.readyState == XMLHttpRequest.DONE) {
			let status = req.status;
			if (status === 0 || (status >= 200 && status < 400)) {
				if (funcDone)
					funcDone(req.responseText, status);
			} else {
				if (funcError)
					funcError(req.responseText, status);
			}
		}
	}

	if (body) {
		req.setRequestHeader("Content-Type", "application/json");
		console.log("SENDING", body)
		req.send(JSON.stringify(body));
	} else {
		req.send();
	}

	return req;
}