var relMdlEgVal;
var selStmtDescEgVal;
var selStmtEgVal;
var relMdlLabVal;
var selLabVal;
var addSelBtnVal;
var remSelBtnVal;
var rstTxtArValBtnVal;
var psfxSubSubmVal;
var glErrMsg = 'Interní chyba.';

var lang = getUserLanguage();

setValues();

const REL_MDL = 'tst_r';
const SEL_STMT_DESC = 'tst_d_';
const SEL_STMT = 'tst_s_';
const REL_MDL_EG = ''
        + 'foo (bar (PK), bar2 (UK), bar3);\r\n'
        + 'foo2 (bar (PK, UK), bar2 (PK, UK2, FK do foo), bar3 (UK2, FK do foo[[bar2]]));\r\n'
        + 'foo3 (bar (PK, FK do foo2[[bar2, bar3]], FK2 do foo2[[bar2, bar3]]), bar2 (UK, UK2, FK do foo2, FK2 do foo2[[bar2, bar3]]), bar3 (UK2, FK do foo2, FK do foo2[[bar], [bar2, bar3]]));';
const SEL_STMT_DESC_EG = 'Vypsat všechny údaje z tabulky foo';
const SEL_STMT_EG = 'SELECT * FROM foo';

const S = ' ';
const N = '<br>';
const BR = ''
        + '<div class="br">'
            + '<br>'
        + '</div>';
const REL_MDL_LAB = ''
        + '<label id="relMdl">'
            + relMdlLabVal + ':'
        + '</label>';
const SEL_LAB = ''
        + '<label id="sel">'
            + selLabVal + ':'
        + '</label>';
const SEL_NUM = ''
        + '<label class="sel">'
            + 0 + '.' + S
        + '</label>';
const REL_MDL_TXT_AR = ''
        + '<textarea id="relMdl" name="' + REL_MDL + '"'
                + 'placeholder="' + REL_MDL_EG + '">'
        + '</textarea>';
const SEL_STMT_DESC_TXT_AR = ''
            + '<textarea class="selStmtDesc" name="' + SEL_STMT_DESC + '0'
                    + '" placeholder="' + SEL_STMT_DESC_EG + '">'
            + '</textarea>';
const SEL_STMT_TXT_AR = ''
            + '<textarea class="selStmt" name="' + SEL_STMT + '0'
                    + '" placeholder="' + SEL_STMT_EG + '">'
            + '</textarea>';
const ADD_SEL_BTN = ''
        + '<button id="addSel" type="button">'
            + addSelBtnVal
        + '</button>';
const REM_SEL_BTN = ''
        + '<button class="remSel" type="button">'
            + remSelBtnVal
        + '</button>';
const RST_TXT_AR_VAL_BTN = ''
        + '<button class="rstTxtArVal" type="button">'
            + rstTxtArValBtnVal
        + '</button>';
const CMT = ''
        + '<div class="cmt">'
        + '</div>';

function getUserLanguage() {
    var pageURL = decodeURIComponent(window.location.search.substring(1));
    var URLVars = pageURL.split(/;|&/);

    for (var i = 0; i < URLVars.length; i++) {
        var paramName = URLVars[i].split('=');
        var lang;

        if (paramName[0] === 'lang' && !!paramName[1]) {
            lang = paramName[1];
        }
    }

    return lang;
}

function setValues() {

    if (lang === 'cs' || lang === undefined) {
        relMdlEgVal = 'Příklad zápisu relačního modelu';
        selStmtDescEgVal = 'Příklad zápisu popisu příkazů SELECT';
        selStmtEgVal = 'Příklad zápisu příkazů SELECT';
        relMdlLabVal = 'Relační model';
        selLabVal = 'Popisy příkazů SELECT a příkazy SELECT';
        addSelBtnVal = 'Přidat SELECT';
        remSelBtnVal = 'Odstranit';
        rstTxtArValBtnVal = 'Restartovat';
        psfxSubSubmVal = 'odevzdat';
    } else {
        relMdlEgVal = 'Relational model example';
        selStmtDescEgVal = 'SELECT statement description example';
        selStmtEgVal = 'SELECT statement example';
        relMdlLabVal = 'Relational model';
        selLabVal = 'SELECT statement descriptions and SELECT statements';
        addSelBtnVal = 'Add SELECT';
        remSelBtnVal = 'Remove';
        rstTxtArValBtnVal = 'Reset';
        psfxSubSubmVal = 'submit';
        glErrMsg = 'Internal error.';
    }
}

String.prototype.contains = function (str) {
    return this.indexOf(str) > -1;
};

function setFunctionName(arg) {
    fcnName = arg.callee.toString().match(/^[^(]+/)[0].replace(/function /, '');
}

function logError(err) {
    var errMsg = err.stack;

    if (errMsg !== undefined) {
        if (!errMsg.contains(err.name)) {
            errMsg = err + ' at ' + errMsg;
        }
    } else {
        if (fcnName !== undefined) {
            err += ' at ' + fcnName;
        }

        errMsg = err;
    }

    if (!(typeof (console) === 'undefined' || typeof (console.error) === 'undefined')) {
        console.error(errMsg);
    }
}

window.onerror = function () {
    alert(glErrMsg);
};


// The implementation below uses jQuery

const ACC_TXT_ID = 'div#PB168RopotAccTxt';
const DEF_ERR_MSG_ID = 'div#PB168RopotDefErrMsg';
const ID = 'div#PB168Ropot';
const TST_STG = 'textarea[name^="tst_"][name$="_e_a_1"]';
const ANS = ''
        + 'textarea[name^="' + REL_MDL + '"],'
        + 'textarea[name^="' + SEL_STMT_DESC + '"],'
        + 'textarea[name^="' + SEL_STMT + '"]';
const MAX_SEL = 10;
const STG_ID = ID.replace(/^span#/, '');
const STG_NUM = STG_ID + 'Num';

var user;
var uco;
var $extSrvTxtAr;
var $tstForm;
var evaldAns;
var num = 1;
var sprtStg = (typeof (Storage) !== 'undefined') ? true : false;
var fcnName;
var isChrome = !!window.chrome && !!window.chrome.webstore;
var isOpera = (!!window.opr && !!opr.addons) || !!window.opera || navigator.userAgent.indexOf(' OPR/') >= 0;

if (!(isChrome || isOpera)) {
    var newBtmPos;
}

function loadAccompanyingText() {
    setFunctionName(arguments);

    var relMdlEg = REL_MDL_EG.replace(/(\r?\n|\r)/g, N);
    var selStmtDescEg = SEL_STMT_DESC_EG.replace(/(\r?\n|\r)/g, N);
    var selStmtEg = SEL_STMT_EG.replace(/(\r?\n|\r)/g, N);

    $(ACC_TXT_ID).append(''
            + relMdlEgVal + ':'
            + BR
            + '<span class="eg">'
                + relMdlEg
            + '</span>'
            + BR + BR
            + selStmtDescEgVal + ':'
            + BR
            + '<span class="eg">'
                + selStmtDescEg
            + '</span>'
            + BR + BR
            + selStmtEgVal + ':'
            + BR
            + '<span class="eg">'
                + selStmtEg
            + '</span>'
            + '');
}

function loadRopotContent() {
    setFunctionName(arguments);

    $(ID).append(''
            + REL_MDL_LAB
            + '<div id="relMdlContr">'
                + BR
                + REL_MDL_TXT_AR + '<span class="btnContr">'
                                     + '<span class="btnContr2">'
                                         + RST_TXT_AR_VAL_BTN
                                         + BR
                                         + ADD_SEL_BTN
                                     + '</span>'
                                 + '</span>'
            + '</div>'
            + BR + BR + BR
            + '');
}

function updateButtonContainerPosition() {
    setFunctionName(arguments);

    var isMozilla = typeof (InstallTrigger) !== 'undefined';
    var isMSIE = false || !!document.documentMode;
    var isSafari = Object.prototype.toString.call(window.HTMLElement).indexOf('Constructor') > 0;
    var $btm = $(ID).find('span.btnContr');
    var btmPos = $btm.css('bottom');
    var posVal = btmPos.match(/-?\d+/);
    var posType = btmPos.replace(posVal, '');

    if (posType === 'px') {
        var newPosVal;

        if (isMozilla) {
            newPosVal = posVal / 6;
        } else if (isMSIE) {
            newPosVal = posVal * (-1.25);
        } else if (isSafari) {
            newPosVal = posVal * 0.25;
        }

        newBtmPos = newPosVal + posType;
        $btm.css('bottom', newBtmPos);
    }
}

if (!sprtStg) {
    function getCookie(cName) {
        setFunctionName(arguments);

        var name = cName + '=';
        var encodedCookie = encodeURIComponent(document.cookie);
        var decodedCookie = decodeURIComponent(encodedCookie);
        var ca = decodedCookie.split(';');

        for (var i = 0; i < ca.length; i++) {
            var c = ca[i];

            while (c.charAt(0) === ' ') {
                c = c.substring(1);
            }

            if (c.indexOf(name) === 0) {
                var cVal = c.substring(name.length, c.length);

                cVal = cVal.replace(/\#\.\#/g, ';');
                cVal = cVal.replace(/\#\-\#/g, ',');
                cVal = cVal.replace(/\#\_\#/g, ' ');
                cVal = cVal.replace(/\#\^\#/g, '\r\n');

                return cVal;
            }
        }

        return '';
    }

    function setCookie(cName, cVal) {
        setFunctionName(arguments);

        if (typeof cVal === 'string') {
            cVal = cVal.replace(/;/g, '#.#');
            cVal = cVal.replace(/,/g, '#-#');
            cVal = cVal.replace(/ /g, '#_#');
            cVal = cVal.replace(/(\r?\n|\r)/g, '#^#');
        }

        var c = cName + '=' + cVal + ';';
        var cSize = (document.cookie + c).length;
        var cCnt = document.cookie.split(';').length;

        if (cSize <= 4093 && cCnt < 50) {
            document.cookie = c;
        }
    }

    function deleteCookie(cName) {
        setFunctionName(arguments);

        document.cookie = cName + '=; expires=Tue, 28 Jan 1919 12:34:56 GMT;';
    }
}

function getTextAreasSize() {
    setFunctionName(arguments);

    var txtArsSize = {};

    $(ID).find('textarea').each(function () {
        var txtArSize = {};

        txtArSize['w'] = $(this).outerWidth();
        txtArSize['h'] = $(this).outerHeight();

        var name = $(this).attr('name');
        var ans = new RegExp('^(' + REL_MDL + '|' + SEL_STMT_DESC + '|' + SEL_STMT + ')');

        if (name !== undefined && name.match(ans)) {
            var selStmtDesc = new RegExp('^' + SEL_STMT_DESC);

            if (name.match(selStmtDesc)) {
                txtArSize['w'] = '100%';
            }

            txtArsSize['[name="' + name + '"]'] = txtArSize;
        } else {
            var id = $(this).attr('id');

            if (id !== undefined) {
                txtArsSize['#' + id] = txtArSize;
            } else {
                var cls = $(this).attr('class');

                if (cls !== undefined) {
                    txtArsSize['[class="' + cls + '"]'] = txtArSize;
                } else if (name !== undefined) {
                    txtArsSize['[name="' + name + '"]'] = txtArSize;
                }
            }
        }
    });

    return txtArsSize;
}

function setTextAreasSize(txtArsSize) {
    setFunctionName(arguments);

    for (var attr in txtArsSize) {
        var txtArSize = txtArsSize[attr];

        for (var key in txtArSize) {
            if (key === 'w' || key === 'h') {
                var dim = (key === 'w') ? 'width' : 'height';
                var size = txtArSize[key];

                $(ID).find('textarea' + attr).css(dim, size);
            }
        }
    }
}

function splitRelationalModel(relMdl) {
    setFunctionName(arguments);

    var relsArr = relMdl.split(';');

    if (relsArr.length > 1 && relsArr.slice(-1)[0] === '') {
        relsArr.splice(-1, 1);
    }

    if (evaldAns !== undefined) {

        for (var evaldAwrType in evaldAns) {

            if (evaldAwrType === REL_MDL) {
                var evaldRels = evaldAns[evaldAwrType].val;

                break;
            }
        }
    }

    var awrRels = {};
    var n = 1;

    for (var i = 0; i < relsArr.length; i++) {
        var relVal = relsArr[i];
        var evald = false;
        var isOk = false;

        if (evaldAns !== undefined) {

            for (var evaldRelNum in evaldRels) {
                var evaldRelVal = evaldRels[evaldRelNum].awrRel;

                if (relVal.trim() === evaldRelVal.trim()) {
                    evald = true;
                    isOk = evaldRels[evaldRelNum].isOk;

                    break;
                }
            }
        }

        var relNum = 'r' + n;
        var awrRel = {'evald': evald, 'isOk': isOk, 'awrRel': relVal};

        awrRels[relNum] = awrRel;

        n++;
    }

    return awrRels;
}

$.fn.exists = function () {
    return $(this).length !== 0;
};

function getComment(awrType, $awrCmt) {
    setFunctionName(arguments);

    var awrCmt;

    switch (awrType.replace(/\d+/, '')) {
        case SEL_STMT_DESC:
            var $selStmtDescCmt = $awrCmt.find('span.selStmtDescCmt');

            awrCmt = $selStmtDescCmt.exists() ? $selStmtDescCmt.text() : '';

            break;
        case SEL_STMT:
            var $selStmtCmt = $awrCmt.find('span.selStmtCmt');

            awrCmt = $selStmtCmt.exists() ? $selStmtCmt.text() : '';

            break;
        default:
            awrCmt = $awrCmt.exists() ? $awrCmt.text() : '';
            break;
    }

    return awrCmt;
}

function setComment($awrType, awrType, awrCmt) {
    setFunctionName(arguments);

    $awrType.addClass('invalid');

    if ($awrType.css('box-shadow') === 'none') {
        $awrType.removeClass('invalid');
        $awrType.addClass('alternativeInvalid');
    }

    var $awrContr = $awrType.closest('div#relMdlContr, div.selContr2');
    var $awrCmt = $awrContr.find('div.cmt');
    var hasCmt = true;

    if (!$awrCmt.exists()) {
        $awrContr.append(''
                + BR
                + CMT
                + '');

        $awrCmt = $awrContr.find('div.cmt');
        hasCmt = false;
    }

    switch (awrType.replace(/\d+/, '')) {
        case SEL_STMT_DESC:

            $awrCmt.prepend(''
                    + '<span class="selStmtDescCmt">'
                        + awrCmt
                    + '</span>'
                    + (!hasCmt ? '' : N)
                    + '');

            break;
        case SEL_STMT:

            $awrCmt.append(''
                    + (!hasCmt ? '' : N)
                    + '<span class="selStmtCmt">'
                        + awrCmt
                    + '</span>'
                    + '');

            break;
        default:

            $awrCmt.append(''
                    + awrCmt
                    + '');

            break;
    }
}

function getAnswers() {
    setFunctionName(arguments);

    var ans = {};

    $(ID).find(ANS).each(function () {
        var awrType = $(this).attr('name');
        var awrVal = $(this).val();
        var evald = false;

        if (evaldAns !== undefined) {

            for (var evaldAwrType in evaldAns) {
                var evaldAwrVal = evaldAns[evaldAwrType].val;

                if (awrType.substring(0, 5) === evaldAwrType.substring(0, 5)) {
                    if (typeof (evaldAwrVal) === 'string') {
                        if (awrVal.trim() === evaldAwrVal.trim()) {
                            evald = true;

                            break;
                        }
                    }
                }
            }
        }

        if (awrType === REL_MDL && evald === false) {
            awrVal = splitRelationalModel(awrVal);
        }

        var $awrCmt = $(this).closest('div#relMdlContr, div.selContr').find('div.cmt');
        var awrCmt = evald ? getComment(awrType, $awrCmt) : "";
        var awr = {'evald': evald, 'val': awrVal, 'cmt': awrCmt};

        ans[awrType] = awr;
    });

    return ans;
}

function setAnswers(ans) {
    setFunctionName(arguments);

    for (var awrType in ans) {
        var awrVal = ans[awrType].val;
        var awrCmt = ans[awrType].cmt;
        /***/var ramBool = Math.random() >= 0.5;
        awrCmt = ramBool ? 'ERROR: incorrect answer' : '';/***/
        var $awrType = $(ID).find('textarea[name="' + awrType + '"]');

        if (awrVal !== undefined) {
            if (typeof (awrVal) === 'string') {
                $awrType.val(awrVal);
            } else {
                var awrRelMdl = '';
                var awrRels = awrVal;

                for (var relNum in awrRels) {
                    var relVal = awrRels[relNum].awrRel;

                    awrRelMdl += relVal + ';';
                }

                if (awrRelMdl.length === 1) {
                    awrRelMdl = '';
                }

                $awrType.val(awrRelMdl);
            }
        }

        if (awrCmt !== undefined && awrCmt.length) {
            setComment($awrType, awrType, awrCmt);
        }
    }
}

function generateSelectContainers(ropotMtdtJSON) {
    setFunctionName(arguments);

    var ropotMtdt = JSON.parse(ropotMtdtJSON);
    var currNum = ropotMtdt[STG_NUM];

    if (currNum > 1) {
        for (var i = 0; i < currNum - 1; i++) {
            addSelect();
        }
    }

    setTextAreasSize(ropotMtdt.txtArsSize);
}

function loadRopotMetaData() {
    setFunctionName(arguments);

    var ropotMtdtJSON;

    if (sprtStg) {
        ropotMtdtJSON = sessionStorage.getItem('ropotMtdt');
    } else {
        ropotMtdtJSON = getCookie('ropotMtdt');

        deleteCookie('ropotMtdt');
    }

    var is1stOpd = true;

    if (!(ropotMtdtJSON == null || ropotMtdtJSON === '')) {
        generateSelectContainers(ropotMtdtJSON);

        is1stOpd = false;
    }

    return is1stOpd;
}

function saveRopotMetaData() {
    setFunctionName(arguments);

    var ropotMtdt = {};

    ropotMtdt[STG_NUM] = num;
    ropotMtdt['txtArsSize'] = getTextAreasSize();

    var ropotMtdtJSON = JSON.stringify(ropotMtdt);

    if (sprtStg) {
        sessionStorage.setItem('ropotMtdt', ropotMtdtJSON);
    } else {
        setCookie('ropotMtdt', ropotMtdtJSON);
    }
}

function getDataFromExternalService(is1stOpd) {
    setFunctionName(arguments);

    /***//*var $extSrvAns = $tstForm.find('font').first();

    if ($extSrvAns.exists()) {
        var extSrvAnsJSON = $extSrvAns.text();

        try {
            var extSrvAns = JSON.parse(extSrvAnsJSON);

            if (is1stOpd) {
                var relMdlFromDB = extSrvAns.relMdl;

                if (relMdlFromDB !== undefined) {
                    $(ID).find('textarea[name^="' + REL_MDL + '"]').val(relMdlFromDB);
                }
            } else {
                evaldAns = extSrvAns;

                if (evaldAns !== undefined) {
                    setAnswers(evaldAns);
                }
            }

            $extSrvAns.remove();
        } catch (err) {
            logError(err);
        }
    }*//***/
    /***/if (sprtStg) {
        extSrvAnsJSON = sessionStorage.getItem('studAns');
    } else {
        extSrvAnsJSON = getCookie('studAns');

        deleteCookie('studAns');
    }

    if (extSrvAnsJSON !== undefined) {

        try {
            var extSrvAns = JSON.parse(extSrvAnsJSON);

            if (is1stOpd) {
                var relMdlFromDB = extSrvAns.relMdl;

                if (relMdlFromDB !== undefined) {
                    $(ID).find('textarea[name^="' + REL_MDL + '"]').val(relMdlFromDB);
                }
            } else {
                evaldAns = JSON.parse(extSrvAnsJSON).ans;

                if (evaldAns !== undefined) {
                    setAnswers(evaldAns);
                }
            }
        } catch (err) {
            // not valid JSON string -- ignore it
        }
    }/***/
}

function setDataForExternalService() {
    setFunctionName(arguments);

    var studAns = {'uco': uco};
    studAns['name'] = user.match(/^[^(,]+/)[0].trim();
    studAns['ans'] = getAnswers();

    var studAnsJSON = JSON.stringify(studAns);

    $extSrvTxtAr.val(studAnsJSON);
    /***/if (sprtStg) {
        sessionStorage.setItem('studAns', studAnsJSON);
    } else {
        setCookie('studAns', studAnsJSON);
    }/***/
}

function removeDefaultErrorMessage() {
    setFunctionName(arguments);

    $(DEF_ERR_MSG_ID).remove();
}

function loadRopot() {
    setFunctionName(arguments);

    loadAccompanyingText();
    loadRopotContent();

    var is1stOpd = true;

    try {
        if (!(isChrome || isOpera)) {
            updateButtonContainerPosition();
        }

        is1stOpd = loadRopotMetaData();
    } catch (err) {
        logError(err);
    }

    getDataFromExternalService(is1stOpd);
    removeDefaultErrorMessage();
}

function saveRopot() {
    setFunctionName(arguments);

    try {
        saveRopotMetaData();
    } catch (err) {
        logError(err);
    }

    setDataForExternalService();
}

function emptyRopot() {
    setFunctionName(arguments);

    $(ID).empty();
}

function editSubmitButtonValue() {
    setFunctionName(arguments);

    var $subm = $tstForm.find(':submit').last();
    var submVal = $subm.val();

    if (!submVal.contains(psfxSubSubmVal)) {
        var prfxSubmVal = submVal.substring(0, submVal.indexOf(' '));
        var psfxSubmVal = submVal.substring(submVal.indexOf(' '), submVal.length);
        var prfxSubSubmVal = (lang === 'cs' || lang === undefined) ? ' a ' : ' and ';

        if (submVal.contains(prfxSubSubmVal)) {
            prfxSubSubmVal = ', ';
        }

        var subSubmVal = prfxSubSubmVal + psfxSubSubmVal;
        var newSubmVal = prfxSubmVal + subSubmVal + psfxSubmVal;

        $subm.val(newSubmVal);
    }
}

function updateOrderAttributes() {
    setFunctionName(arguments);

    var $appdSel = $(ID).find('div.selContr').last();
    var $selNum = $appdSel.find('label.sel');
    var edOrd = $selNum.html().replace(/\d+/, num);

    if (num < 10) {
        edOrd = S + S + edOrd;
    }

    $selNum.html(edOrd);

    var $selStmtDesc = $appdSel.find('textarea.selStmtDesc');
    var edName = $selStmtDesc.attr('name').replace(/\d+/, num);

    $selStmtDesc.attr('name', edName);

    var $selStmt = $appdSel.find('textarea.selStmt');
    edName = $selStmt.attr('name').replace(/\d+/, num);

    $selStmt.attr('name', edName);

    var x = num % 3;

    if (x === 1) {
        x = '';
    } else if (x === 0) {
        x = 3;
    }

    var edSelStmtDescPlHlr = $selStmtDesc.attr('placeholder') + x;
    var edSelStmtPlHlr = $selStmt.attr('placeholder') + x;

    $selStmtDesc.attr('placeholder', edSelStmtDescPlHlr);
    $selStmt.attr('placeholder', edSelStmtPlHlr);
}

function addSelect() {
    setFunctionName(arguments);

    try {
        if (num <= MAX_SEL) {
            $(ID).append(''
                    + (num === 1 ? (SEL_LAB + BR) : '')
                    + '<div class="selContr">'
                        + BR
                        + SEL_NUM + '<div class="selContr2">'
                                      + '<div class="selContr3">'
                                          + SEL_STMT_DESC_TXT_AR + N
                                          + SEL_STMT_TXT_AR
                                      + '</div>' + '<span class="btnContr">'
                                                     + '<span class="btnContr2">'
                                                         + RST_TXT_AR_VAL_BTN
                                                         + BR
                                                         + REM_SEL_BTN
                                                     + '</span>'
                                                 + '</span>'
                                  + '</div>'
                        + BR
                    + '</div>'
                    + '');

            updateOrderAttributes();

            num++;
        }

        if (!(isChrome || isOpera) && newBtmPos !== undefined) {
            $(ID).find('span.btnContr').last().css('bottom', newBtmPos);
        }
    } catch (err) {
        logError(err);

        throw err;
    }
}

function resetStudentAnswer() {
    setFunctionName(arguments);

    try {
        $(this).closest('div#relMdlContr, div.selContr').find(ANS).val('');
    } catch (err) {
        logError(err);

        throw err;
    }
}

function moveOrderAttributes($selToRem) {
    setFunctionName(arguments);

    var prevSelNum = $selToRem.find('label.sel').text().match(/\d+/);
    var prevSelStmtDescNum = $selToRem.find('textarea.selStmtDesc').attr('name').match(/\d+/);
    var prevSelStmtNum = $selToRem.find('textarea.selStmt').attr('name').match(/\d+/);

    $selToRem.nextAll().each(function () {
        var $selNum = $(this).find('label.sel');
        var ord = $selNum.text();
        var currNum = ord.match(/\d+/);

        if (prevSelNum.toString().length === currNum.toString().length) {
            var newNum = ord.replace(/\d+/, prevSelNum);

            $selNum.text(newNum);
        } else {
            ord = $selNum.html();
            var newOrd = S + S + ord.replace(/\d+/, prevSelNum);

            $selNum.html(newOrd);
        }

        prevSelNum = currNum;

        var $selStmtDesc = $(this).find('textarea.selStmtDesc');
        var name = $selStmtDesc.attr('name');
        currNum = name.match(/\d+/);
        var newName = name.replace(/\d+/, prevSelStmtDescNum);

        $selStmtDesc.attr('name', newName);
        prevSelStmtDescNum = currNum;

        var $selStmt = $(this).find('textarea.selStmt');
        name = $selStmt.attr('name');
        currNum = name.match(/\d+/);
        newName = name.replace(/\d+/, prevSelStmtNum);

        $selStmt.attr('name', newName);
        prevSelStmtNum = currNum;
    });
}

function removeSelect() {
    setFunctionName(arguments);

    try {
        var $selToRem = $(this).closest('div.selContr');
        var isNotLast = $selToRem.next().exists();
        var haveSels = $(ID).find('div.selContr').length - 1;

        if (haveSels) {
            if (isNotLast) {
                moveOrderAttributes($selToRem);
            }
        } else {
            $(ID).find('label#sel').remove();
        }

        $selToRem.remove();

        num--;
    } catch (err) {
        logError(err);

        throw err;
    }
}

$(document).ready(function () {
    try {
        // Get user's name and UCO
        user = $('div#id-uzivatel').text();
        uco = user.match(/\d+/)[0];

        // Hidden textarea -- e: question to store values for external service
        $extSrvTxtAr = $(ID).closest('table').find(TST_STG);

        try {
            // Load ROPOT for submitting relational models and queries
            loadRopot();
        } catch (err) {
            // Empty ROPOT to have only error message in the content
            emptyRopot();

            logError(err);
        }

        // IS MU ROPOT
        $tstForm = $(ID).closest('form[name="testform"]');

        try {
            // Edit submit button value
            editSubmitButtonValue();
        } catch (err) {
            logError(err);
        }

        // Responses to any buttons
        $(ID).find('button#addSel').click(addSelect);
        $(ID).on('click', 'button.remSel', removeSelect);
        $(ID).on('click', 'button.rstTxtArVal', resetStudentAnswer);

        $tstForm.submit(saveRopot);
    } catch (err) {
        logError(err);

        throw err;
    }
});