'use strict';

{

function fetchJSON(url, cb) {

const xhr = new XMLHttpRequest();

xhr.open('GET', url);

xhr.responseType = 'json';

xhr.onload = () => {

if (xhr.status < 400) {

cb(null, xhr.response);

} else {

cb(new Error(`Network error: ${xhr.status} - ${xhr.statusText}`));

}

};

xhr.onerror = () => cb(new Error('Network request failed'));

xhr.send();

}

function createAndAppend(name, parent, options = {}) {

const elem = document.createElement(name);

parent.appendChild(elem);

Object.keys(options).forEach(key => {

const value = options[key];

if (key === 'text') {

elem.textContent = value;

} else {

elem.setAttribute(key, value);

}

});

return elem;

}

function main(url) {

fetchJSON(url, (err, data) => {

const root = document.getElementById('root');

if (err) {

createAndAppend('div', root, { text: err.message, class: 'alert-error' });

} else {

createAndAppend('pre', root, { text: JSON.stringify(data, null, 2) });

}

});

}

const REPOS_URL = 'https://api.github.com/orgs/foocoding/repos?per_page=100';

window.onload = () => main(REPOS_URL);

}