/*
 * 'this' -> original element
 * 1. argument: browser event
 * 2.argument: ui object
 */

(function($) {

	$.ui.plugin.add("draggable", "cursor", {
		start: function(e,ui) {
			var t = $('body');
			if (t.css("cursor")) ui.options._cursor = t.css("cursor");
			t.css("cursor", ui.options.cursor);
		},
		stop: function(e,ui) {
			if (ui.options._cursor) $('body').css("cursor", ui.options._cursor);
		}
	});

	$.ui.plugin.add("draggable", "zIndex", {
		start: function(e,ui) {
			var t = $(ui.helper);
			if(t.css("zIndex")) ui.options._zIndex = t.css("zIndex");
			t.css('zIndex', ui.options.zIndex);
		},
		stop: function(e,ui) {
			if(ui.options._zIndex) $(ui.helper).css('zIndex', ui.options._zIndex);
		}
	});

	$.ui.plugin.add("draggable", "opacity", {
		start: function(e,ui) {
			var t = $(ui.helper);
			if(t.css("opacity")) ui.options._opacity = t.css("opacity");
			t.css('opacity', ui.options.opacity);
		},
		stop: function(e,ui) {
			if(ui.options._opacity) $(ui.helper).css('opacity', ui.options._opacity);
		}
	});


	$.ui.plugin.add("draggable", "revert", {
		stop: function(e,ui) {
			var self = ui.instance;
			self.cancelHelperRemoval = true;
			$(ui.helper).animate({ left: self.originalPosition.left, top: self.originalPosition.top }, parseInt(ui.options.revert, 10) || 500, function() {
				if(ui.options.helper != 'original') self.helper.remove();
				self.clear();
			});
		}
	});

	$.ui.plugin.add("draggable", "iframeFix", {
		start: function(e,ui) {

			var o = ui.options;
			if(ui.instance.slowMode) return; // Make clones on top of iframes (only if we are not in slowMode)
			
			if(o.iframeFix.constructor == Array) {
				for(var i=0;i<o.iframeFix.length;i++) {
					var co = $(o.iframeFix[i]).offset({ border: false });
					$("<div class='DragDropIframeFix' style='background: #fff;'></div>").css("width", $(o.iframeFix[i])[0].offsetWidth+"px").css("height", $(o.iframeFix[i])[0].offsetHeight+"px").css("position", "absolute").css("opacity", "0.001").css("z-index", "1000").css("top", co.top+"px").css("left", co.left+"px").appendTo("body");
				}		
			} else {
				$("iframe").each(function() {					
					var co = $(this).offset({ border: false });
					$("<div class='DragDropIframeFix' style='background: #fff;'></div>").css("width", this.offsetWidth+"px").css("height", this.offsetHeight+"px").css("position", "absolute").css("opacity", "0.001").css("z-index", "1000").css("top", co.top+"px").css("left", co.left+"px").appendTo("body");
				});							
			}

		},
		stop: function(e,ui) {
			if(ui.options.iframeFix) $("div.DragDropIframeFix").each(function() { this.parentNode.removeChild(this); }); //Remove frame helpers	
		}
	});
	
	$.ui.plugin.add("draggable", "containment", {
		start: function(e,ui) {

			var o = ui.options;
			if((o.containment.left != undefined || o.containment.constructor == Array) && !o._containment) return;
			if(!o._containment) o._containment = o.containment;

			if(o._containment == 'parent') o._containment = this[0].parentNode;
			if(o._containment == 'document') {
				o.containment = [
					0,
					0,
					$(document).width(),
					($(document).height() || document.body.parentNode.scrollHeight)
				];
			} else { //I'm a node, so compute top/left/right/bottom

				var ce = $(o._containment)[0];
				var co = $(o._containment).offset();

				o.containment = [
					co.left,
					co.top,
					co.left+(ce.offsetWidth || ce.scrollWidth),
					co.top+(ce.offsetHeight || ce.scrollHeight)
				];
			}

		},
		drag: function(e,ui) {

			var o = ui.options;
			var h = ui.helper;
			var c = o.containment;
			var self = ui.instance;
			
			if(c.constructor == Array) {
				if((ui.absolutePosition.left < c[0])) self.position.left = c[0] - (self.offset.left - self.clickOffset.left);
				if((ui.absolutePosition.top < c[1])) self.position.top = c[1] - (self.offset.top - self.clickOffset.top);
				if(ui.absolutePosition.left - c[2] + self.helperProportions.width >= 0) self.position.left = c[2] - (self.offset.left - self.clickOffset.left) - self.helperProportions.width;
				if(ui.absolutePosition.top - c[3] + self.helperProportions.height >= 0) self.position.top = c[3] - (self.offset.top - self.clickOffset.top) - self.helperProportions.height;
			} else {
				if((ui.position.left < c.left)) self.position.left = c.left;
				if((ui.position.top < c.top)) self.position.top = c.top;
				if(ui.position.left - self.offsetParent.innerWidth() + self.helperProportions.width + c.right + (parseInt(self.offsetParent.css("borderLeftWidth"), 10) || 0) + (parseInt(self.offsetParent.css("borderRightWidth"), 10) || 0) >= 0) self.position.left = self.offsetParent.innerWidth() - self.helperProportions.width - c.right - (parseInt(self.offsetParent.css("borderLeftWidth"), 10) || 0) - (parseInt(self.offsetParent.css("borderRightWidth"), 10) || 0);
				if(ui.position.top - self.offsetParent.innerHeight() + self.helperProportions.height + c.bottom + (parseInt(self.offsetParent.css("borderTopWidth"), 10) || 0) + (parseInt(self.offsetParent.css("borderBottomWidth"), 10) || 0) >= 0) self.position.top = self.offsetParent.innerHeight() - self.helperProportions.height - c.bottom - (parseInt(self.offsetParent.css("borderTopWidth"), 10) || 0) - (parseInt(self.offsetParent.css("borderBottomWidth"), 10) || 0);
			}

		}
	});

	$.ui.plugin.add("draggable", "grid", {
		drag: function(e,ui) {
			var o = ui.options;
			ui.instance.position.left = ui.instance.originalPosition.left + Math.round((e.pageX - ui.instance._pageX) / o.grid[0]) * o.grid[0];
			ui.instance.position.top = ui.instance.originalPosition.top + Math.round((e.pageY - ui.instance._pageY) / o.grid[1]) * o.grid[1];
		}
	});

	$.ui.plugin.add("draggable", "axis", {
		drag: function(e,ui) {
			var o = ui.options;
			if(o.constraint) o.axis = o.constraint; //Legacy check
			o.axis == 'x' ? ui.instance.position.top = ui.instance.originalPosition.top : ui.instance.position.left = ui.instance.originalPosition.left;
		}
	});

	$.ui.plugin.add("draggable", "scroll", {
		start: function(e,ui) {
			var o = ui.options;
			o.scrollSensitivity	= o.scrollSensitivity || 20;
			o.scrollSpeed		= o.scrollSpeed || 20;

			ui.instance.overflowY = function(el) {
				do { if(/auto|scroll/.test(el.css('overflow')) || /auto|scroll/.test(el.css('overflow-y'))) return el; el = el.parent(); } while (el[0].parentNode);
				return $(document);
			}(this);
			ui.instance.overflowX = function(el) {
				do { if(/auto|scroll/.test(el.css('overflow')) || /auto|scroll/.test(el.css('overflow-x'))) return el; el = el.parent(); } while (el[0].parentNode);
				return $(document);
			}(this);
		},
		drag: function(e,ui) {
			
			var o = ui.options;
			var i = ui.instance;

			if(i.overflowY[0] != document && i.overflowY[0].tagName != 'HTML') {
				if(i.overflowY[0].offsetHeight - (ui.position.top - i.overflowY[0].scrollTop + i.clickOffset.top) < o.scrollSensitivity)
					i.overflowY[0].scrollTop = i.overflowY[0].scrollTop + o.scrollSpeed;
				if((ui.position.top - i.overflowY[0].scrollTop + i.clickOffset.top) < o.scrollSensitivity)
					i.overflowY[0].scrollTop = i.overflowY[0].scrollTop - o.scrollSpeed;				
			} else {
				//$(document.body).append('<p>'+(e.pageY - $(document).scrollTop())+'</p>');
				if(e.pageY - $(document).scrollTop() < o.scrollSensitivity)
					$(document).scrollTop($(document).scrollTop() - o.scrollSpeed);
				if($(window).height() - (e.pageY - $(document).scrollTop()) < o.scrollSensitivity)
					$(document).scrollTop($(document).scrollTop() + o.scrollSpeed);
			}
			
			if(i.overflowX[0] != document && i.overflowX[0].tagName != 'HTML') {
				if(i.overflowX[0].offsetWidth - (ui.position.left - i.overflowX[0].scrollLeft + i.clickOffset.left) < o.scrollSensitivity)
					i.overflowX[0].scrollLeft = i.overflowX[0].scrollLeft + o.scrollSpeed;
				if((ui.position.top - i.overflowX[0].scrollLeft + i.clickOffset.left) < o.scrollSensitivity)
					i.overflowX[0].scrollLeft = i.overflowX[0].scrollLeft - o.scrollSpeed;				
			} else {
				if(e.pageX - $(document).scrollLeft() < o.scrollSensitivity)
					$(document).scrollLeft($(document).scrollLeft() - o.scrollSpeed);
				if($(window).width() - (e.pageX - $(document).scrollLeft()) < o.scrollSensitivity)
					$(document).scrollLeft($(document).scrollLeft() + o.scrollSpeed);
			}
			
			ui.instance.recallOffset(e);

		}
	});

	//TODO: wrapHelper, snap

})(jQuery);