$(document).ready(function () {
	$.fn.TeamTouristSelect = function ( dataset, select2options ) {

		/*
		 * In this function,
		 * we override some of the default select2 options.
		 * Using $.extend, we can merge together the user options with these options.
		*/

		$.extend(select2options, {

			initSelection: function (element, callback) {

				/*
				 * On first launch, look up the text that is
				 * the value attribute of the input and return
				 * the object in the select2 array.
				 * Then, set it as the current select2 option by running "callback" on it
				*/

		        var selection = new Array();
		        selection = $.grep(dataset, function (e) {
					return e.text == element.val();
		        });

		        callback(selection[0]);

		    },

		    query: function (options) {

		    	/*
		    	 * Set up the number of results we want to load at one time
		    	*/

		        var pageSize = 25;
		        var startIndex = (options.page - 1) * pageSize;
				var filteredData = dataset;

				/*
				 * The user must type in a valid term
				*/

				if (options.term && options.term.length > 0) {

					/*
					 * Only find the results if this is a new search
					 * options.context will already be set if we are only loading new pages,
					 * 				   not finding new data.
					*/

					if (!options.context) {

		                var term = options.term.toLowerCase();

		                /*
		                 * Loop through the dataset and match the text or category
		                 * to the term.
		                 * If there is a match, add it to the selection array.
		                */

						var selection = new Array();
						for (x = 0; x < dataset.length; x++) {

							obj = dataset[x];

							if (obj.text.toLowerCase().indexOf(term) !== -1 || obj.category.toLowerCase().indexOf(term) !== -1) {
								selection.push(obj);
							}

						}

						options.context = selection;

					}

		            filteredData = options.context;

		        }

		        /*
		         * Now, filter out the number of results we want to find
		         * based on the pages we are loading.
		        */

		        shortenedData = filteredData.slice(startIndex, startIndex + pageSize);

		        categories = new Array();
		        categorisedData = new Array();

		        /*
		         * Sort the final data into its categories.
		        */

		        for (j=0; j < shortenedData.length; j++) {

		        	/*
		        	 * If the category doesn't exist in our categories array
		        	 * then create it with an empty value for children
		        	*/

		        	if (categories.indexOf(shortenedData[j].category) === -1) {
		        		categories.push(shortenedData[j].category);
		        		categorisedData.push({ text: shortenedData[j].category, children: [] });
		        	}

		        	/*
		        	 * Assuming the category has been added to the categories array,
		        	 * we can insert this row into the categories children array
		        	*/

		        	index = categories.indexOf(shortenedData[j].category);
		        	categorisedData[index].children.push(shortenedData[j]);
		        }

		        /*
		         * To fix a bug: if the category we are loading is the same as the last category loaded from the last search,
		         * then don't bother showing the same category twice.
		        */

		        if (startIndex > 0 && categorisedData[0].text == filteredData[startIndex - 1].category) {
		        	categorisedData[0].text = "";  	
		        }

		        /*
		         * Perform the callback on the new data.
		        */

		        options.callback({
		            context: filteredData,
		            results: categorisedData,
		            more: (startIndex + pageSize) < filteredData.length
		        });

		    }

		});

		/*
		 * Run select2 with the new options.
		*/

		$(this).select2(select2options);

	}

});