if (typeof(_cas) == "undefined") 
    _cas = {};



// ======================= DOM PROTOTYPE ======================= 

if (typeof(_cas.DOM) == "undefined") 
    _cas.DOM = {};


/**
 * Get element.
 * 
 * @param {Object} elementOrId - element itself or it's id
 */
_cas.DOM.getElement = function(elementOrId){
    var t = typeof(elementOrId);
    if (t == "undefined") 
        return 0;
    else 
        if (t == "string") {
            var re = document.getElementById(elementOrId);
            if (!re) 
                return 0;
            else 
                if (typeof(re.appendChild) != "undefined") 
                    return re;
                else 
                    return 0;
        }
        else 
            if (typeof(elementOrId.appendChild) != "undefined") 
                return elementOrId;
            else 
                return 0;
};


/**
 * Remove all children in given container.
 * @param {Object} element - element id or element itself
 */
_cas.DOM.removeChildren = function(element){
    var element = _cas.DOM.getElement(element);
    
    while (element.firstChild) 
        element.removeChild(element.firstChild);
    
    //while (element.hasChildNodes()) 
    //    element.removeChild(element.childNodes[0]);
}


/**
 * Set inner html or inner text or set child (removing others if exists)
 * 
 * @param {Object} elementOrId
 * @param {Object} content object to be appended, inner HTML or inner text
 * @param {Object} isHTML
 */
_cas.DOM.setContent = function(elementOrId, content, isHTML){
    //get element object
    var elt = _cas.DOM.getElement(elementOrId);
    
    _cas.DOM.removeChildren(elt);
    
    //set inner text/html/child
    var contentType = typeof(content);
    
    if (contentType == "string" && !isHTML) 
        elt.appendChild(document.createTextNode(content));
    else 
        if (contentType == "string" && isHTML) 
            elt.innerHTML = content;
        else 
            if (contentType == "object") 
                elt.appendChild(content);
    
}


/**
 * Hide element
 * 
 * @param {Object} e - element id or element itself
 */
_cas.DOM.hideElement = function(e){
    var element = _cas.DOM.getElement(e);
    element.style.display = 'none';
}


/**
 * Show element
 * 
 * @param {Object} e - element id or element itself
 */
_cas.DOM.showElement = function(e){
    var element = _cas.DOM.getElement(e);
    element.style.display = 'block';
}


/**
 * Get origin position of [given] event
 * @param {Object} event
 */
_cas.DOM.getEventPosition = function(event){
    event = event || window.event;
    var cursor = {
        x: 0,
        y: 0
    };
    if (event.pageX || event.pageY) {
        cursor.x = event.pageX;
        cursor.y = event.pageY;
    }
    else {
        var de = document.documentElement;
        var b = document.body;
        cursor.x = event.clientX + 
            (de.scrollLeft || b.scrollLeft) - (de.clientLeft || 0);
        cursor.y = event.clientY +
            (de.scrollTop || b.scrollTop) - (de.clientTop || 0);
    }
    return cursor;
}


// ======================= WINDOW ======================= 

if (typeof(_cas.window) == "undefined") 
    _cas.window = {};


/**
 * Popup opener
 * 
 * @param {Object} URL
 * @param {Object} id
 */
_cas.window.openWindow = function(URL, id){
    /// popup opener
    date = new Date();
    if (window[id]) {
        window[id].close();
    }
    window[id] = window.open(URL, 'ID' + date.getTime(), 'toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=1,width=400,height=300');
    window[id].focus();
}


/**
 * Get window size
 */
_cas.window.getWindowSize = function(){
    var wsize = {
        width: 900,
        height: 600
    };
    if (window.innerWidth) {
        wsize.width = window.innerWidth;
        wsize.height = window.innerHeight;
    }
    else 
        if (document.documentElement.clientWidth) {
            wsize.width = document.documentElement.clientWidth;
            wsize.height = document.documentElement.clientHeight;
        }
        else 
            if (document.body.clientWidth) {
                wsize.width = document.body.clientWidth;
                wsize.height = document.body.clientHeight;
            }
    return wsize;
}


_cas.window.getViewPort = function(){
    var viewport = {
        x1: 0,
        y1: 0,
        x2: 0,
        y2: 0
    };
    if (window.pageXOffset || window.pageYOffset) {
        viewport.x1 = window.pageXOffset;
        viewport.y1 = window.pageYOffset;
    }
    else {
        var de = document.documentElement;
        var b = document.body;
        viewport.x1 = (de.scrollLeft || b.scrollLeft) - (de.clientLeft || 0);
        viewport.y1 = (de.scrollTop || b.scrollTop) - (de.clientTop || 0);
    }
    var wsize = _cas.window.getWindowSize();
    viewport.x2 = viewport.x1 + wsize.width - 1;
    viewport.y2 = viewport.y1 + wsize.height - 1;
//    alert("(" + viewport.x1 + ", " + viewport.y1 + "), (" + viewport.x2 + ", " + viewport.y2 + ")");
    return viewport;
}


/**
 * Resize & center window
 * 
 * @param {Object} width
 * @param {Object} height
 */
_cas.window.resizeWindow = function(width, height){
    /// resizing
    
    //XXX: id of body element is hardcoded here. This is suxx 
    
    if (height) {
        winHeight = height
    }
    else {
        winHeight = document.getElementById('bodyArea').offsetHeight + 30
    };
    if (width) {
        winWidth = width
    }
    else {
        winWidth = document.getElementById('bodyArea').offsetWidth + 50
    };
    
    window.resizeTo(winWidth, winHeight);
    
    /// centering
    window.moveTo((screen.availWidth - winWidth) / 2, (screen.availHeight - winHeight) / 2);
    window.focus();
}

// cannot combine reload_window(extra, go2top) from meetings.js and the one from timeline.js
// they use their own variables inside
// also cannot combine it with _cas.window.reloadWindow(anchorName) 
// because of internal variable filter_state 
// So, i leave it as it is

// upd: 
// XXX: by the way, filter_state is not used anywhere (does not work)
// so we can get rid of it...

// ======================== COMMON =========================


if (typeof(_cas.common) == "undefined") 
    _cas.common = {};


/**
 * System event notifier. Show given element and center it.
 * 
 * @param {Object} elementOrId
 */
_cas.common.showSystemMessagBox = function(elementOrId) {
    var systemMessageBox = _cas.DOM.getElement(elementOrId);
    if (systemMessageBox) {
        window.setTimeout( function(){ _cas.common.doShowSystemMessagBox(systemMessageBox)}, 400);
    }
}


//helper for _cas.common.showSystemMessagBox. 
//We need it because IE scrolls window to desired anchor not immediately
//so without this trick system message will not be scrolled. 
_cas.common.doShowSystemMessagBox = function(systemMessageBox) {
    _cas.DOM.showElement(systemMessageBox); 
    var size = {x : systemMessageBox.offsetWidth, y : systemMessageBox.offsetHeight};
    var viewPort = _cas.window.getViewPort();
    systemMessageBox.style.left = (viewPort.x1 + viewPort.x2 - size.x)/2;
    systemMessageBox.style.top = (viewPort.y1 + viewPort.y2 - size.y)/2;
}