//async function postJson(url, data = {}, options = {}) {
	//const response = await fetch(url, {
		//method: "POST",
		//mode: "no-cors",
		//credentials: "include",
		//headers: { "Content-Type": "application/json" },
		//redirect: "follow",
		//referrerPolicy: "no-referrer",
		//body: JSON.stringify(data),
		//...options
	//});
	////return await response.json();
	//return response;
//}

//var endpoint = "https://mattermost.zeus.gent/api/v4"; // Must not end with slash
var endpoint = "http://localhost:8080"; // Must not end with slash
var username = "fill me in";
var password = "fill me in";


function scopeToArg(f) {
	return function(...rest) {
		return f(this, ...rest);
	}
}

function postJson(url, data={}, options={}) {
	const prom = new Promise((resolve, reject) => {
		let oReq = new XMLHttpRequest();
		oReq.addEventListener("load", scopeToArg(resolve));
		oReq.addEventListener("abort", scopeToArg(reject));
		oReq.addEventListener("error", scopeToArg(reject));
		oReq.addEventListener("timeout", scopeToArg(reject));
		oReq.open("POST", url);
		oReq.send(JSON.stringify(data));

	});
	return prom;
}

var token = null;

function printIt(response) {
	console.log(response);
	if (response.status == 0) {
		document.body.innerText = "Network error";
		return;
	}

	if (200 <= response.status && response.status < 300) {
		try {
			const json = JSON.parse(response.response);
			document.body.innerHTML = "";
			const pre = document.createElement("pre");
			pre.innerText = "Received " + JSON.stringify(json, null, 2);
			document.body.appendChild(pre);

			token = response.getResponseHeader("token");
			window.localStorage.setItem("token", token);

			return token;
		} catch(e) {
			document.body.innerText = "The server did not reply with a valid JSON object. Make sure the server URL points to a Mattermost instance that is working correctly.";
		}

	} else {
		console.log(response.getAllResponseHeaders());
		try {
			const json = JSON.parse(response.response);
			document.body.innerText = "Failed to log in: " + json.message;
		} catch(e) {
			document.body.innerText = "Error: " + response.statusText;
		}
	}
}


postJson(`${endpoint}/api/v4/users/login`, {
	"login_id": username,
	"password": password
})
	.then(printIt, printIt)
	.then(token => console.log(token));