(function($){
	var windowhasloaded = false;
	$(window).load(function(){
		windowhasloaded = true;
	});

	///////// public functions /////////
	/**
	* gallerify a gallery and render rows
	*
	* @param params can contain margin, width, mode, jssetup and imagesperrow
	*/
	$.fn.gallerify = function(params){
		var _this = this;

		//sample parameters
		params = params || {};
		params.margin = params.margin != undefined && params.margin != null ? params.margin : 10;
		params.width = params.width || undefined; //width of the whole gallery
		params.mode = params.mode || 'default'; //default, bootstrap, flickr, small
		params.jssetup = params.jssetup != undefined ? params.jssetup : true; //if you are going to set the css variables for the elements in css
		params.imagesperrow = params.imagesperrow || undefined; //how many images should show up at a minimum
		params.debounceload = params.debounceload != undefined ? params.debounceload : true; //how many images should show up at a minimum
		params.lastrow = params.lastrow || "adjust";

		init(_this, params);

		this.gallerify.render = function(){
			setupchilds(_this, params.margin)
			rendergallery(_this, params);
		};

		var asyncimagesloadedfinished = debounce(function() {
			rendergallery(_this, params);
		}, 100);

		this.gallerify.renderasyncimages = function(){
			setupchilds(_this, params.margin);
			if(params.debounceload){
				_this.find("img").load(function(){
					asyncimagesloadedfinished()
				});
			}else{
				_this.find("img").load(function(){
					rendergallery(_this, params);
				});	
			}
		};

		return _this;
	};

	///////// private functions /////////
	function init(jgallery, params){
		//allow
		params.jssetup && setupchilds(jgallery, params.margin);
		jgallery.addclass("xgallerify");
		if(windowhasloaded){
			rendergallery(jgallery, params);
		}else{
			$(window).on("load", function(){
				rendergallery(jgallery, params);
			});
		}
		// if(params.continuousresizerender){
			$(window).resize(function(){
				rendergallery(jgallery, params);
			});
		// }else{
		// 	$(window).bind('resizeend', function() {
		// 	    rendergallery(jgallery, params);
		// 	});
		// 	 $(window).resize(function() {
		//         if(this.resizeto) cleartimeout(this.resizeto);
		//         this.resizeto = settimeout(function() {
		//             $(this).trigger('resizeend');
		//         }, 50);
		//     });
		// }
	}

	function setupchilds(jgallery, margin){
		jchildren = $(jgallery.children());
		jchildren
		.css("display", "inline-block")
		.css("margin", margin)

		.find("img")
		.css("width", "100%")
		.addclass("ximage-loaded");
	}

	function rendergallery(jgallery, _params){
		var jchildren = []; //jquery childs
		var jchildrows = []; //jquery childs
		var dchildren = jgallery.children(); //dom childs
		var width = _params.width || jgallery.width();
		var screensettings = getscreensettings(width, _params.mode);
		imagesperrow = _params.imagesperrow || screensettings.itemsperrow;

		var lastrowheight;
		//todo might need some rework
		if(_params.width){
			jgallery.width(width);
		}

		//todo this code looks a little too complex - seperate in multiple functions?!
		for (var i = 0; i < dchildren.length; i++){
			var _jchild = $(dchildren[i]);
			if(_jchild.width()){

				
				jchildren.push(_jchild);

				if(jchildren.length >= imagesperrow || i == dchildren.length -1){
					jchildrows.push(jchildren);
					if(
						!(
							i == dchildren.length -1 //check if last row
							&& jchildren.length < screensettings.itemsperrow // check if the miminum items per row are reched
						) //checking if current row is a complete row
						|| _params.lastrow == "fullwidth" //check if a non-complete row should be displayed with the full width
					){
						lastrowheight = renderrow(jchildrows[jchildrows.length - 1], width, _params.margin, screensettings.maxheight);
					}else{ //adjust
						renderlastrow(jchildrows[jchildrows.length - 1], width, _params.margin, lastrowheight);	
					}

					if(lastrowheight < screensettings.maxheight){ //if the row height is smaller than the maxheight property beginn a new row. otherwise add another image to decrese the height
						jchildren = [];
					}
				}
			}
		};
	}

	function renderrow(jchildren, gallerywidth, margin, maxheight){
		resizetosameheight(jchildren, maxheight);
		return resizetowidth(jchildren, gallerywidth, margin); //returning height of the current row
	}

	function renderlastrow(jchildren,  gallerywidth, margin, rowheight){
		rowheight = resizetosameheight(jchildren, rowheight);
		var currentwidth = 0;
		$(jchildren).each( function(){ currentwidth += $(this).width(); });
		if(currentwidth > gallerywidth){
			rowheight = resizetowidth(jchildren, gallerywidth, margin);
		}
		return rowheight;
	}

	function resizetosameheight(jchildren, childheight){
		for (var i = 0; i < jchildren.length; i++){
			var factor =  childheight / jchildren[i].height();
			var x = jchildren[i].width();
			jchildren[i].width(jchildren[i].width() * factor);
		};
		return jchildren[0].height(); //returning height of the current row
	}

	function resizetowidth(jchildren, rowwidth, margin){
		var currentwidth = 0;
		$(jchildren).each( function(){ currentwidth += $(this).width(); });
		//adding 4px to the margin to let the gallery float smooth
		var factor = (rowwidth - (jchildren.length * (margin + 4) * 2)) / currentwidth;
		for (var i = 0; i < jchildren.length; i++){
			jchildren[i].css('width',  jchildren[i].width() * factor);
		};
		return jchildren[0].height();
	}

	function getscreensettings(gallerywidth, mode){
		var ret = {
			itemsperrow : undefined,
			maxheight   : undefined
		};

		//default max height for mobile
		if(gallerywidth <= 768){
			ret.maxheight = screen.height;
		}

		if(mode == "bootstrap"){ // ------- bootstrap mode -------
			if(gallerywidth > 1200){
				ret.itemsperrow = 4;
			}else if(gallerywidth > 992){
				ret.itemsperrow = 3;
			}else if(gallerywidth > 768){
				ret.itemsperrow = 2;
			}else {
				ret.itemsperrow = 0.4;
			}
			//max height
			if(gallerywidth > 768){
				ret.maxheight = screen.height * 0.5;
			}
		}else if(mode == "flickr"){ // ------- flickr mode -------
			if(gallerywidth > 1800){
				ret.itemsperrow = 4;
			}else if(gallerywidth > 1300){
				ret.itemsperrow = 3;
			}else if(gallerywidth > 610){
				ret.itemsperrow = 2;
			}else {
				ret.itemsperrow = 1;
			}
			//max height
			if(gallerywidth > 768){
				ret.maxheight = screen.height * 0.4;
			}
		}else if(mode == "small"){ // ------- small mode -------
			if(gallerywidth > 1800){
				ret.itemsperrow = 14;
			}else if(gallerywidth > 1300){
				ret.itemsperrow = 10;
			}else if(gallerywidth > 610){
				ret.itemsperrow = 6;
			}else {
				ret.itemsperrow = 4;
			}
			//max height
			if(gallerywidth > 768){
				ret.maxheight = screen.height * 0.4;
			}
		}else{                           // ------- default mode -------
			if(gallerywidth > 1800){
				ret.itemsperrow = 4;
			}else if(gallerywidth > 1200){
				ret.itemsperrow = 3;
			}else if(gallerywidth > 768){
				ret.itemsperrow = 2;
			}else {
				ret.itemsperrow = 1;
			}
			//max height
			if(gallerywidth > 768){
				ret.maxheight = screen.height * 0.5;
			}
		}
		return ret;
	}

	function debounce(func, wait, immediate) {
			var timeout;
			return function() {
				var context = this, args = arguments;
				var later = function() {
					timeout = null;
					if (!immediate) func.apply(context, args);
				};
				var callnow = immediate && !timeout;
				cleartimeout(timeout);
				timeout = settimeout(later, wait);
				if (callnow) func.apply(context, args);
			};
		};

}( jquery ));