// ??????Util?????????? 
var Util = new Object();
Util.getUserAgent = navigator.userAgent;
Util.isGecko = Util.getUserAgent.indexOf("Gecko") != -1;
Util.isOpera = Util.getUserAgent.indexOf("Opera") != -1;

Util.bodyScollTop = 0;

Util.getOffset = function (el, isLeft) {
	var retValue = 0;
	while (el != null) {
		retValue += el["offset" + (isLeft ? "Left" : "Top")];
		el = el.offsetParent;
	}
	return retValue;
};

Util.bindFunction = function (el, fucName) {
	return function () {
		return el[fucName].apply(el, arguments);
	}
};

Util.re_calcOff = function (el) {
	for (var i=0; i<Util.dragArray.length; i++) {
		var ele = Util.dragArray[i];
		ele.elm.pagePosLeft = Util.getOffset(ele.elm, true);
		ele.elm.pagePosTop = Util.getOffset(ele.elm, false);
	}
	
	var nextSib = el.elm.nextSibling;
	while (nextSib) {
		nextSib.pagePosTop -= el.elm.offsetHeight;
		nextSib = nextSib.nextSibling;
	}
};

Util.hide = function () {
	Util.rootElement.style.display = "none";
};

Util.show = function () {
	Util.rootElement.style.display = "block";
};

// ???????????
ghostElement = null;

getGhostElement = function () {
	if (!ghostElement) {
		ghostElement = document.createElement("DIV");
		ghostElement.style.background = "transparent";
		ghostElement.style.border = "1px dashed red";
		ghostElement.innerHTML = "&nbsp;";
	}
	return ghostElement;
};

// ????????Element???
function draggable(el) {
	this._dragStart = start_Drag;
	this._drag = when_Drag;
	this._dragEnd = end_Drag;
	this._afterDrag = after_Drag;
	this.isDragging = false;
	this.elm = el;
	this.header = document.getElementById(el.id + "_t");
	
	if (this.header) {
		this.header.style.cursor = "move";
		
		Drag.init(this.header, this.elm);
		this.elm.onDragStart = Util.bindFunction(this, "_dragStart");
		this.elm.onDrag = Util.bindFunction(this, "_drag");
		this.elm.onDragEnd = Util.bindFunction(this, "_dragEnd");
	}
}

// ???????
function start_Drag() {
	Util.re_calcOff(this);
	this.origNextSibling = this.elm.nextSibling;
	var _ghostElement = getGhostElement();
	var offH = this.elm.offsetHeight;
	
	if(Util.isGecko) {
		offH -= parseInt(_ghostElement.style.borderTopWidth) * 2;
	}
	var offW = this.elm.offsetWidth;
	var offLeft = Util.getOffset(this.elm, true);
	var offTop = Util.getOffset(this.elm, false);
	
	Util.hide();
	
	this.elm.style.width = offW + "px";
	_ghostElement.style.height = offH + "px";
	
	this.elm.parentNode.insertBefore(_ghostElement, this.elm.nextSibling);
	
	this.elm.style.position = "absolute";
	this.elm.style.zIndex = 100;
	this.elm.style.left = offLeft + "px";
	this.elm.style.top = offTop + "px";
	
	Util.show();
	Util.bodyScollTop = document.documentElement.scrollTop;
	this.isDragging = false;
	return false;
}

var mousewheelTop = 0;
var str = "";
var wheelflg = "false";

function document.onmousewheel(){
	wheelflg = "true";
}

// ??????
function when_Drag(clientX, clientY) {
	if (!this.isDragging) {
		this.elm.style.filter = "alpha(opacity=70)";
		this.elm.style.opacity = 0.7;
		this.isDragging = true;
	}
	
	mousewheelTop = document.documentElement.scrollTop - Util.bodyScollTop;
	if (wheelflg == "true") {
		str = this.elm.style.top;
		str = str.substring(0, str.indexOf("px")) * 1 + mousewheelTop;
	
		this.elm.style.top = str;
		wheelflg = "false";
		Util.bodyScollTop = document.documentElement.scrollTop;
		mousewheelTop = 0;
	}
	
	var found = null;
	var max_distance = 100000000;	

	for (var i=0; i<Util.dragArray.length; i++) {
		var ele = Util.dragArray[i];
		var distance = Math.sqrt(Math.pow(clientX - ele.elm.pagePosLeft, 2) + Math.pow(clientY - ele.elm.pagePosTop, 2));
		
		if (ele == this) {
			continue;
		}
		
		if (isNaN(distance)) {
			continue;
		}
		
		if (distance < max_distance) {
			max_distance = distance;
			found = ele;
		}
	}

	var _ghostElement = getGhostElement();
	
	if (found != null && _ghostElement.nextSibling != found.elm) {
		found.elm.parentNode.insertBefore(_ghostElement, found.elm);
		if (Util.isOpera) {
			document.body.style.display = "none";
			document.body.style.display = "";
		}
	}
}

// ???????????
function end_Drag() {
	if (this._afterDrag()) {
		var element = this.elm;
		var elementId = element.id.substring(element.id.indexOf("m_") + 2, element.id.lastIndexOf("_"));
		var beforeElementId = "";
		while(element.nextSibling != null && element.nextSibling.id.indexOf("m_") == -1) {
			element = element.nextSibling;
		}
		if (element.nextSibling != null) {
			element = element.nextSibling;
		
			beforeElementId =  element.id.substring(element.id.indexOf("m_") + 2, element.id.lastIndexOf("_"));
			sendMoveElement(elementId, beforeElementId, composePageId);
		} else {
			beforeElementId =  element.parentNode.id.substring(0, element.parentNode.id.lastIndexOf("_"));
			sendMoveElement(elementId, beforeElementId, composePageId);
		}
		
	}
	return true;
}

// ???????
function after_Drag() {
	var returnValue = false;
	
	Util.hide();
	
	this.elm.style.position = "";
	this.elm.style.width = "";
	this.elm.style.zIndex = "";
	this.elm.style.filter = "";
	this.elm.style.opacity = "";
	
	var ele = getGhostElement();

	var width_m = this.elm.id;
	var width_col = ele.parentNode.id
	width_m = width_m.substring(width_m.lastIndexOf("_") + 1);
	width_col = width_col.substring(width_col.lastIndexOf("_") + 1);

	if (width_col >= width_m) {
		if (ele.nextSibling != this.origNextSibling) {
			ele.parentNode.insertBefore(this.elm, ele.nextSibling);
			returnValue = true;
		}
	} else {
		alert("对不起！该模块或区块不能拖入小于它自身宽度的区域！");
	}
	
	ele.parentNode.removeChild(ele);
	
	Util.show();
	
	if (Util.isOpera) {
		document.body.style.display = "none";
		document.body.style.display = "block";
	}
	
	return returnValue;
}

// ???Element???
var Drag = {
	obj: null,
	
	init: function (elementHeader, element) {
		elementHeader.onmousedown = Drag.start;
		elementHeader.obj = element;
		if (isNaN(parseInt(element.style.left))) {
			element.style.left = "0px";
		}
		if (isNaN(parseInt(element.style.top))) {
			element.style.top = "0px";
		}
		
		element.onDragStart = new Function();
		element.onDragEnd = new Function();
		element.onDrag = new Function();
	},
	
	start: function (event) {
		event = Drag.fixE(event);
		if (event.which != 1) {
			return true;
		}
		
		var element = Drag.obj = this.obj;
		
		element.onDragStart();
		
		element.lastMouseX = event.clientX;
		element.lastMouseY = event.clientY;
		
		document.onmouseup = Drag.end;
		document.onmousemove = Drag.drag;
		return false;
	},
	
	drag: function (event) {
	    event = Drag.fixE(event);
	    if (event.which == 0) {
	        return Drag.end();
    	}

	    var element = Drag.obj;
	    var _clientX = event.clientY;
	    var _clientY = event.clientX;
	    if (element.lastMouseX == _clientY && element.lastMouseY == _clientX) {
	        return false;
	    }

	    var _lastX = parseInt(element.style.top);
	    var _lastY = parseInt(element.style.left);

	    var newX, newY;
	    newX = _lastY + _clientY - element.lastMouseX;
	    newY = _lastX + _clientX - element.lastMouseY;

	    element.style.left = newX + "px";
	    element.style.top = newY + "px";

	    element.lastMouseX = _clientY;
	    element.lastMouseY = _clientX;

	    element.onDrag(newX, newY);
	    return false;
	},
	
	end: function (event) {
		event = Drag.fixE(event);
		
		document.onmousemove = null;
		document.onmouseup = null;
		
		var _onDragEndFuc = Drag.obj.onDragEnd();
		Drag.obj = null;
		
		return _onDragEndFuc;
	},
	
	fixE: function (ig_) {
		if (typeof ig_ == "undefined") {
			ig_ = window.event;
		}
		if (typeof ig_.layerX == "undefined") {
			ig_.layerX = ig_.offsetX;
		}
		if (typeof ig_.layerY == "undefined") {
			ig_.layerY = ig_.offsetY;
		}
		if (typeof ig_.which == "undefined") {
			ig_.which = ig_.button;
		}
		return ig_;
	}
}

//??????
var _IG_initDrag = function (el) {
	Util.rootElement = el;
	
	var count = 0;
	Util.allDiv = document.getElementById("page_body").getElementsByTagName("DIV");
	Util.column = new Array();
	for (var i=0; i<Util.allDiv.length; i++) {
		if (Util.allDiv[i].id.indexOf("col_") != -1) {
			Util.column[count] = Util.allDiv[i];
			count++;
		}
	}

	Util.dragArray = new Array();
	
	count = 0;
	for (var i=0; i<Util.column.length; i++) {
		var ele = Util.column[i];
		for (var j=0; j<ele.childNodes.length; j++) {
			var ele_sub = ele.childNodes[j];
			if (ele_sub.tagName == "DIV") {
				Util.dragArray[count] = new draggable(ele_sub);
				count++;
			}
		}
	}
};