const COOKIE_NAME_SESSID = '_rb_sessionid';
    const COOKIE_NAME_TEST = '_rb_test';

    var sessionId = getCookie(COOKIE_NAME_SESSID);
    if (sessionId === undefined) {
        document.cookie = COOKIE_NAME_SESSID + '=' + getUniqueId();
        sessionId = getCookie(COOKIE_NAME_SESSID);
    }

    document.addEventListener('click', e => {
        if (e.target.classList.contains('rb-bubble')) {
            document.querySelector('#rb-button').remove();
            renderWidget();
        }
        if (e.target.classList.contains('rb-remove')) {
            document.querySelector('#rb-chat').remove();
            renderButton();
        }
    });

    const test = getCookie(COOKIE_NAME_TEST) === undefined ? 0 : 1;
//    const test = 1;
    const host = test ? 'lk2.in-fo.ru' : 'lk.sales-management-center.com';

    renderStyle();
    renderButton();

    function renderStyle() {
        let linkStyle = document.createElement('link');
        linkStyle.setAttribute('rel', 'stylesheet');
        linkStyle.setAttribute('href', `https://${host}/css/chat/widgetjs.css`);
        document.head.appendChild(linkStyle);
    }

    function renderButton() {
        let elemDiv = document.createElement('div');
        elemDiv.setAttribute('id', 'rb-button');
        elemDiv.innerHTML = '<span class="rb-bubble" aria-hidden="true">Напишите нам</span>';
        document.body.appendChild(elemDiv);
    }

    function renderWidget() {
        let elemDiv = document.createElement('div');
        elemDiv.setAttribute('id', 'rb-chat');
 
        let elemRemoveDiv = document.createElement('div');
        elemRemoveDiv.setAttribute('class', 'rb-remove');

        let elemIframe = document.createElement('iframe');
        elemIframe.setAttribute('src', 'https://' + host + '/chat/widget/679fe280947fc'
            + '?session_id=' + sessionId
            + '&test=' + test
        );
        elemIframe.style.cssText = 'border:none;height:300px;';

        elemDiv.appendChild(elemRemoveDiv);
        elemDiv.appendChild(elemIframe);
        document.body.appendChild(elemDiv);
    }

    function getUniqueId() {
        let idstr = String.fromCharCode(Math.floor((Math.random() * 25) + 65)).toLowerCase();
        do {
            let ascicode = Math.floor((Math.random() * 42) + 48);
            if (ascicode < 58 || ascicode > 64) {
                idstr += String.fromCharCode(ascicode).toLowerCase();
            }
        } while (idstr.length < 32);
        return (idstr);
    }

    function getCookie(name) {
        let matches = document.cookie.match(new RegExp("(?:^|; )" + name.replace(/([\.$?*|{}\(\)\[\]\\\/\+^])/g, '\\$1') + "=([^;]*)"));
        return matches ? decodeURIComponent(matches[1]) : undefined;
    }