// Demo variables
// iMouseDown represents the current mouse button state: up or down
/*
lMouseState represents the previous mouse button state so that we can
check for button clicks and button releases:

if(iMouseDown && !lMouseState) // button just clicked!
if(!iMouseDown && lMouseState) // button just released!
*/
var mouseOffset = null;
var iMouseDown  = false;
var lMouseState = false;
var dragObject  = null;

// Demo 0 variables
var DragDrops   = [];  // контейнеры
var curTarget   = null;
var lastTarget  = null;
var dragHelper  = null;
var tempDiv     = null;
var rootParent  = null;
var rootSibling = null;

// коррекция левого поля 
var verticalOnly = 0;
var margin_left = 6;
var saved_left = 0;
var dropCallback = null;

Number.prototype.NaN0=function(){return isNaN(this)?0:this;}

// запихнем все объекты внутрь контейнера
function CreateDragContainer(dc){
    if (dragHelper == null) {
        // Create our helper object that will show the item while dragging
        dragHelper = document.createElement('DIV');
        dragHelper.style.cssText = 'position:absolute; display:none;';
        document.body.appendChild(dragHelper);
    }

    var index = DragDrops.length;
	DragDrops[index] = [];
    dropCallback = dc;

    for(var i=1; i<arguments.length; i++){
		var cObj = arguments[i];
		DragDrops[index].push(cObj);
		cObj.setAttribute('DropObj', index);

		// Проходимся по всем объектам, добавляем в драглист либо их, либо их хендлеры
		for(var j=0; j<cObj.childNodes.length; j++){
            // Firefox puts in lots of #text nodes...skip these
			if (cObj.childNodes[j].nodeName=='#text') continue;
            cObj.childNodes[j].setAttribute('DragObj', index);
		}
	}
    if (!document.onmousemove) document.onmousemove = mouseMove;
    if (!document.onmousedown) document.onmousedown = mouseDown;
    if (!document.onmouseup) document.onmouseup   = mouseUp;
}

function getPosition(e){
	var left = 0;
	var top  = 0;
	while (e.offsetParent){
		left += e.offsetLeft + (e.currentStyle?(parseInt(e.currentStyle.borderLeftWidth)).NaN0():0);
		top  += e.offsetTop  + (e.currentStyle?(parseInt(e.currentStyle.borderTopWidth)).NaN0():0);
		e     = e.offsetParent;
	}

	left += e.offsetLeft + (e.currentStyle?(parseInt(e.currentStyle.borderLeftWidth)).NaN0():0);
	top  += e.offsetTop  + (e.currentStyle?(parseInt(e.currentStyle.borderTopWidth)).NaN0():0);

	return {x:left, y:top};

}

function mouseCoords(ev){
	if(ev.pageX || ev.pageY){
		return {x:ev.pageX, y:ev.pageY};
	}
	return {
		x:ev.clientX + document.body.scrollLeft - document.body.clientLeft,
		y:ev.clientY + document.body.scrollTop  - document.body.clientTop
	};
}

function getMouseOffset(target, ev){
	ev = ev || window.event;

	var docPos    = getPosition(target);
	var mousePos  = mouseCoords(ev);
	return {x:mousePos.x - docPos.x, y:mousePos.y - docPos.y};
}

function mouseMove(ev){
	ev         = ev || window.event;

	/*
	We are setting target to whatever item the mouse is currently on

	Firefox uses event.target here, MSIE uses event.srcElement
	*/
	var target   = ev.target || ev.srcElement;
	var mousePos = mouseCoords(ev);

    // mouseOut event - fires if the item the mouse is on has changed
    if(lastTarget && (target!==lastTarget)){
        // reset the classname for the target element
        var origClass = lastTarget.getAttribute('origClass');
        if(origClass) lastTarget.className = origClass;
    }

    /*
    dragObj is the grouping our item is in (set from the createDragContainer function).
    if the item is not in a grouping we ignore it since it can't be dragged with this
    script.
    */
    var dragObj = null; // target.getAttribute('DragObj');
    if (target.dragLink) {
        target = target.dragLink;
        dragObj = target.getAttribute('DragObj');
    }

    // if the mouse was moved over an element that is draggable
    if(dragObj!=null){

        // mouseOver event - Change the item's class if necessary
        if(target!=lastTarget){
            var oClass = target.getAttribute('overClass');
            if(oClass){
                target.setAttribute('origClass', target.className);
                target.className = oClass;
            }
        }

        // if the user is just starting to drag the element
        if(iMouseDown && !lMouseState){
            // mouseDown target
            curTarget     = target;

            // Record the mouse x and y offset for the element
            rootParent    = curTarget.parentNode;
            rootSibling   = curTarget.nextSibling;

            mouseOffset   = getMouseOffset(target, ev);

            // We remove anything that is in our dragHelper DIV so we can put a new item in it.
            for(var i=0; i<dragHelper.childNodes.length; i++) dragHelper.removeChild(dragHelper.childNodes[i]);

            // Make a copy of the current item and put it in our drag helper.
            var clone = curTarget.cloneNode(true);
            clone.removeAttribute('DragObj'); // disable dragging from our helper DIV (it's already being dragged)
            if (curTarget.dragClass) clone.className = curTarget.dragClass;
            dragHelper.appendChild(clone);
            dragHelper.style.display = 'block';

            /*
            Record the current position of all drag/drop targets related
            to the element.  We do this here so that we do not have to do
            it on the general mouse move event which fires when the mouse
            moves even 1 pixel.  If we don't do this here the script
            would run much slower.
            */
            var dragConts = DragDrops[dragObj];

            /*
            first record the width/height of our drag item.  Then hide it since
            it is going to (potentially) be moved out of its parent.
            */
            curTarget.setAttribute('startWidth',  parseInt(curTarget.offsetWidth));
            curTarget.setAttribute('startHeight', parseInt(curTarget.offsetHeight));
            curTarget.style.display  = 'none';

            saved_left = getPosition(curTarget).x;

            // loop through each possible drop container
            for(var i=0; i<dragConts.length; i++){
                with(dragConts[i]){
                    var pos = getPosition(dragConts[i]);

                    /*
                    save the width, height and position of each container.

                    Even though we are saving the width and height of each
                    container back to the container this is much faster because
                    we are saving the number and do not have to run through
                    any calculations again.  Also, offsetHeight and offsetWidth
                    are both fairly slow.  You would never normally notice any
                    performance hit from these two functions but our code is
                    going to be running hundreds of times each second so every
                    little bit helps!

                    Note that the biggest performance gain here, by far, comes
                    from not having to run through the getPosition function
                    hundreds of times.
                    */
                    setAttribute('startWidth',  parseInt(offsetWidth));
                    setAttribute('startHeight', parseInt(offsetHeight));
                    setAttribute('startLeft',   pos.x);
                    setAttribute('startTop',    pos.y);
                }

                // loop through each child element of each container
                for(var j=0; j<dragConts[i].childNodes.length; j++){
                    with(dragConts[i].childNodes[j]){
                        if((nodeName=='#text') || (dragConts[i].childNodes[j]==curTarget)) continue;

                        var pos = getPosition(dragConts[i].childNodes[j]);

                        // save the width, height and position of each element
                        setAttribute('startWidth',  parseInt(offsetWidth));
                        setAttribute('startHeight', parseInt(offsetHeight));
                        setAttribute('startLeft',   pos.x);
                        setAttribute('startTop',    pos.y);
                    }
                }
            }
        }
    }

    // If we get in here we are dragging something
    if(curTarget){
        // move our helper div to wherever the mouse is (adjusted by mouseOffset)
        dragHelper.style.top  = (mousePos.y - mouseOffset.y) + 'px';
        dragHelper.style.left = (parseInt(verticalOnly?saved_left:(mousePos.x - mouseOffset.x)) - margin_left) + 'px';

        var dragConts  = DragDrops[curTarget.getAttribute('DragObj')];
        var activeCont = null;

        var xPos = mousePos.x - mouseOffset.x + (parseInt(curTarget.getAttribute('startWidth')) /2);
        var yPos = mousePos.y - mouseOffset.y + (parseInt(curTarget.getAttribute('startHeight'))/2);

        // check each drop container to see if our target object is "inside" the container
        for(var i=0; i<dragConts.length; i++){
            with(dragConts[i]){
                if((parseInt(getAttribute('startLeft'))                                           < xPos) &&
                    (parseInt(getAttribute('startTop'))                                            < yPos) &&
                    ((parseInt(getAttribute('startLeft')) + parseInt(getAttribute('startWidth')))  > xPos) &&
                    ((parseInt(getAttribute('startTop'))  + parseInt(getAttribute('startHeight'))) > yPos)){

                        /*
                        our target is inside of our container so save the container into
                        the activeCont variable and then exit the loop since we no longer
                        need to check the rest of the containers
                        */
                        activeCont = dragConts[i];

                        // exit the for loop
                        break;
                }
            }
        }

        // Our target object is in one of our containers.  Check to see where our div belongs
        if(activeCont){
            // beforeNode will hold the first node AFTER where our div belongs
            var beforeNode = null;

            // loop through each child node (skipping text nodes).
            for(var i=activeCont.childNodes.length-1; i>=0; i--){
                with(activeCont.childNodes[i]){
                    if(nodeName=='#text') continue;

                    // if the current item is "After" the item being dragged
                    if(curTarget != activeCont.childNodes[i]                                                  &&
                        ((parseInt(getAttribute('startLeft')) + parseInt(getAttribute('startWidth')))  > xPos) &&
                        ((parseInt(getAttribute('startTop'))  + parseInt(getAttribute('startHeight'))) > yPos)){
                            beforeNode = activeCont.childNodes[i];
                    }
                }
            }

            // the item being dragged belongs before another item
            if(beforeNode){
                if(beforeNode!=curTarget.nextSibling){
                    activeCont.insertBefore(curTarget, beforeNode);
                }

            // the item being dragged belongs at the end of the current container
            } else {
                if((curTarget.nextSibling) || (curTarget.parentNode!=activeCont)){
                    activeCont.appendChild(curTarget);
                }
            }

            // the timeout is here because the container doesn't "immediately" resize
            setTimeout(function(){
            var contPos = getPosition(activeCont);
            activeCont.setAttribute('startWidth',  parseInt(activeCont.offsetWidth));
            activeCont.setAttribute('startHeight', parseInt(activeCont.offsetHeight));
            activeCont.setAttribute('startLeft',   contPos.x);
            activeCont.setAttribute('startTop',    contPos.y);}, 5);

            // make our drag item visible
            if(curTarget.style.display!=''){
                curTarget.style.display    = '';
                curTarget.style.visibility = 'hidden';
            }
        } else {

            // our drag item is not in a container, so hide it.
            if(curTarget.style.display!='none'){
                curTarget.style.display  = 'none';
            }
        }
    }

    // track the current mouse state so we can compare against it next time
    lMouseState = iMouseDown;

    // mouseMove target
    lastTarget  = target;

    if(dragObject){
		dragObject.style.position = 'absolute';
		dragObject.style.top      = mousePos.y - mouseOffset.y;
		dragObject.style.left     = mousePos.x - mouseOffset.x;
	}

	// track the current mouse state so we can compare against it next time
	lMouseState = iMouseDown;

	// this prevents items on the page from being highlighted while dragging
	if(curTarget || dragObject) return false;
}

function mouseUp(ev){
    if(curTarget){
        dragHelper.style.display = 'none';
        if(curTarget.style.display == 'none'){
            if(rootSibling){
                rootParent.insertBefore(curTarget, rootSibling);
            } else {
                rootParent.appendChild(curTarget);
            }
        }
        curTarget.style.display    = '';
        curTarget.style.visibility = 'visible';
        if (dropCallback) dropCallback();
    }
    curTarget  = null;
	dragObject = null;
	iMouseDown = false;
}

function mouseDown(ev){
	ev         = ev || window.event;
	var target = ev.target || ev.srcElement;

    iMouseDown = true;
    if (target.onmousedown || target.getAttribute('DragObj') || target.dragLink){
		return false;
	}

}

function makeDraggable(item){
	if(!item) return;
	item.onmousedown = function(ev){
		dragObject  = this;
		mouseOffset = getMouseOffset(this, ev);
		return false;
	}
}

function makeClickable(item){
	if(!item) return;
	item.onmousedown = function(ev){
		document.getElementById('ClickImage').value = this.name;
	}
}

function addDropTarget(item, target){
	item.setAttribute('droptarget', target);
}