/*
Copyright (c) 2005 Tim Taylor Consulting <http://tool-man.org/>

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
*/

var DragDrop = {
	firstContainer : null,
	lastContainer : null,
        parent_id : null,
        parent_group : null,
	makeListContainer : function(list, group) {
		// each container becomes a linked list node
		if (this.firstContainer == null) {
			this.firstContainer = this.lastContainer = list;
			list.previousContainer = null;
			list.nextContainer = null;
		} else {
			list.previousContainer = this.lastContainer;
			list.nextContainer = null;
			this.lastContainer.nextContainer = list;
			this.lastContainer = list;
		}
		
		// these functions are called when an item is draged over
		// a container or out of a container bounds.  onDragOut
		// is also called when the drag ends with an item having
		// been added to the container
		list.onDragOver = new Function();
		list.onDragOut = new Function();
                list.onDragDrop = new Function();
                list.group = group;
		
    	var items = list.getElementsByTagName( "li" );
    	
		for (var i = 0; i < items.length; i++) {
			DragDrop.makeItemDragable(items[i]);
		}
	},
        
        serData : function ( group, theid ) {
                var container = DragDrop.firstContainer;
		var j = 0;
                var string = "";
                
                while (container != null) {
                
                        if(theid != null && container.id != theid)
                        {
                          container = container.nextContainer;
                          continue;
                        }

                        if(group != null && container.group != group)
                        {
                          container = container.nextContainer;
                          continue;
                        }
                
                        j ++;
                        if(j > 1)
                        {
                          string += ":";
                        }
                        string += container.id;
                        
                        var items = container.getElementsByTagName( "li" );
    	                string += "(";
		        for (var i = 0; i < items.length; i++) {
                            if(i > 0)
                            {
                              string += ",";
                            }
			    string += items[i].id;
		        }
                        string += ")";
                        
			container = container.nextContainer;
		}
                return string;   
        },

	makeItemDragable : function(item) {
		Drag.makeDraggable(item);
		item.setDragThreshold(5);
		
		// tracks if the item is currently outside all containers
		item.isOutside = false;
		
		item.onDragStart = DragDrop.onDragStart;
		item.onDrag = DragDrop.onDrag;
		item.onDragEnd = DragDrop.onDragEnd;
	},

	onDragStart : function(nwPosition, sePosition, nwOffset, seOffset) {
		// update all container bounds, since they may have changed
		// on a previous drag
		//
		// could be more smart about when to do this
		var container = DragDrop.firstContainer;
		while (container != null) {
			container.northwest = Coordinates.northwestOffset( container, true );
			container.southeast = Coordinates.southeastOffset( container, true );
			container = container.nextContainer;
		}
		
		// item starts out over current parent
		this.parentNode.onDragOver();
                parent_id = this.parentNode.id;
                parent_group = this.parentNode.group;
	},

	onDrag : function(nwPosition, sePosition, nwOffset, seOffset) {
		// check if we were nowhere
		if (this.isOutside) {
			// check each container to see if in its bounds
			var container = DragDrop.firstContainer;
			while (container != null) {

				if ((nwOffset.inside( container.northwest, container.southeast ) ||
					seOffset.inside( container.northwest, container.southeast )) && container.group == parent_group) {
					// we're inside this one
					container.onDragOver();
					this.isOutside = false;
					
					// since isOutside was true, the current parent is a
					// temporary clone of some previous container node and
					// it needs to be removed from the document
					var tempParent = this.parentNode;
					tempParent.removeChild( this );
					container.appendChild( this );
					tempParent.parentNode.removeChild( tempParent );
					break;
				}
				container = container.nextContainer;
			}
			// we're still not inside the bounds of any container
			if (this.isOutside)
				return;
		
		// check if we're outside our parent's bounds
		} else if (!(nwOffset.inside( this.parentNode.northwest, this.parentNode.southeast ) ||
			seOffset.inside( this.parentNode.northwest, this.parentNode.southeast ))) {
			
			this.parentNode.onDragOut();
			this.isOutside = true;
			
			// check if we're inside a new container's bounds
			var container = DragDrop.firstContainer;
			while (container != null) {
				if ((nwOffset.inside( container.northwest, container.southeast ) ||
					seOffset.inside( container.northwest, container.southeast )) && container.group == parent_group) {
					// we're inside this one
					container.onDragOver();
					this.isOutside = false;
					this.parentNode.removeChild( this );
					container.appendChild( this );
					break;
				}
				container = container.nextContainer;
			}
			// if we're not in any container now, make a temporary clone of
			// the previous container node and add it to the document
			if (this.isOutside) {
				var tempParent = this.parentNode.cloneNode( false );
				this.parentNode.removeChild( this );
				tempParent.appendChild( this );
				// body puts a border or item at bottom of page if do not have this
                                tempParent.style.border = 0;
				document.getElementsByTagName( "body" ).item(0).appendChild( tempParent );
				return;
			}
		}
		
		// if we get here, we're inside some container bounds, so we do
		// everything the original dragsort script did to swap us into the
		// correct position
		
		var parent = this.parentNode;
				
		var item = this;
		var next = DragUtils.nextItem(item);
		while (next != null && this.offsetTop >= next.offsetTop - 2) {
			var item = next;
			var next = DragUtils.nextItem(item);
		}
		if (this != item) {
			DragUtils.swap(this, next);
			return;
		}

		var item = this;
		var previous = DragUtils.previousItem(item);
		while (previous != null && this.offsetTop <= previous.offsetTop + 2) {
			var item = previous;
			var previous = DragUtils.previousItem(item);
		}
		if (this != item) {
			DragUtils.swap(this, item);
			return;
		}
	},

	onDragEnd : function(nwPosition, sePosition, nwOffset, seOffset) {
		// if the drag ends and we're still outside all containers
		// it's time to remove ourselves from the document or add 
                // to the trash bin
		if (this.isOutside) {
                        var container = DragDrop.firstContainer;
                        while (container != null) {
                           if(container.id == parent_id)
                           {
                             break;
                           }
                           container = container.nextContainer;
                        }
			this.isOutside = false;
			this.parentNode.removeChild( this );
			container.appendChild( this );
                        this.style["top"] = "0px";
		        this.style["left"] = "0px";
                        //var container = DragDrop.firstContainer;
                        //container.appendChild( this );
			return;
		}
		this.parentNode.onDragOut();
                this.parentNode.onDragDrop();
      		this.style["top"] = "0px";
		this.style["left"] = "0px";
	}
};

var DragUtils = {
	swap : function(item1, item2) {
		var parent = item1.parentNode;
		parent.removeChild(item1);
		parent.insertBefore(item1, item2);

		item1.style["top"] = "0px";
		item1.style["left"] = "0px";
	},

	nextItem : function(item) {
		var sibling = item.nextSibling;
		while (sibling != null) {
			if (sibling.nodeName == item.nodeName) return sibling;
			sibling = sibling.nextSibling;
		}
		return null;
	},

	previousItem : function(item) {
		var sibling = item.previousSibling;
		while (sibling != null) {
			if (sibling.nodeName == item.nodeName) return sibling;
			sibling = sibling.previousSibling;
		}
		return null;
	}		
};