/**
 * This jQuery plugin displays pagination links inside the selected elements.
 *
 * @author Gabriel Birke (birke *at* d-scribe *dot* de)
 * @version 1.1
 * @param {int} maxentries Number of entries to paginate
 * @param {Object} opts Several options (see README for documentation)
 * @return {Object} jQuery Object
 */
 
function loadContents(page_id, jq, path, post) {
	$("#content-pane").load(path+(page_id), post);
	return false;
} 
 

function loadPage(page_id, jq, path, post) {
	//$("#content-pane").load(path+(page_id), post);
	
	window.location.href = '/news/P'+(page_id+1);
	return false;
} 
 


 
jQuery.fn.pagination = function(maxentries, opts){
	opts = jQuery.extend({
		path: "",
		hash_path: "",
		post: null,
		items_per_page:10,
		num_display_entries:10,
		current_page:0,
		num_edge_entries:1,
		link_to:"__id__",
		prev_text:"« Prev",
		next_text:"Next »",
		ellipse_text:"...",
		prev_show_always:true,
		next_show_always:true,
		callback:function(){return false;}
	},opts||{});
	
	//alert('post: '+opts.post);
	
return this.each(function() {
		/**
		 * Calculate the maximum number of pages
		 */
		function numPages() {
			return Math.ceil(maxentries/opts.items_per_page);
		}
		
		/**
		 * Calculate start and end point of pagination links depending on 
		 * current_page and num_display_entries.
		 * @return {Array}
		 */
		function getInterval()  {
			var ne_half = Math.ceil(opts.num_display_entries/2)-1; // 5
			var np = numPages();
			if (np > 1) {
				var upper_limit = np-opts.num_display_entries; // 31-10 = 21
				var start = (current_page>ne_half?Math.max(Math.min(current_page-ne_half, upper_limit), 0):0);
				
				if (current_page > ne_half) {
					var end = start + opts.num_display_entries;
				} else {
					var end = current_page>ne_half?Math.min(current_page+ne_half, np):Math.min(opts.num_display_entries, np);
				}
				
				return [start,end];
			} else {
				
				return [0,1];
			}
			
		}
		
		/**
		 * This is the event handling function for the pagination links. 
		 * @param {int} page_id The new page number
		 */
		function pageSelected(page_id, evt){
			current_page = page_id;
			
			drawLinks();
			var continuePropagation = opts.callback(page_id, panel, opts.path, opts.post);
			if (!continuePropagation) {
				
				
				if (evt.stopPropagation) {
					evt.stopPropagation();
				}
				else {
					evt.cancelBubble = true;
				}
			}
			return continuePropagation;
		}
		
		/**
		 * This function inserts the pagination links into the container element
		 */
		function drawLinks() {
			panel.empty();
			var interval = getInterval();
			if (interval[1] > 1) {
				var np = numPages();
				// This helper function returns a handler function that calls pageSelected with the right page_id
				var getClickHandler = function(page_id) {
					if (opts.hash_path.length > 0) {
						window.location.hash = opts.hash_path+(page_id);
					}
					return function(evt){ return pageSelected(page_id,evt); }
				}
				
				// Helper function for generating a single link (or a span tag if it'S the current page)
				var appendItem = function(page_id, appendopts){
					page_id = page_id < 0 ? 0:( page_id < np ? page_id : np-1); // Normalize page id to sane value
					// page id = 26 < 0 ? 0 :   ( 26 < 31 ? 26 : 30 )
					appendopts = jQuery.extend({text:page_id+1, classes:""}, appendopts||{});
					
				
						if(page_id == current_page){
							var lnk = $("<a class='current'>"+(appendopts.text)+"</a>")
								.attr('href', opts.hash_path.length > 0 ? opts.hash_path+(page_id+1) : opts.path+'/P'+(page_id+1))
								.click(function() { return false });
						}
						else
						{
							var lnk = $("<a>"+(appendopts.text)+"</a>")
								.bind("click", getClickHandler(page_id))
								.attr('href', opts.hash_path.length > 0 ? opts.hash_path+(page_id+1) : opts.path+'/P'+(page_id+1));
								
						}
					
					
					if(appendopts.classes){lnk.addClass(appendopts.classes);}
					panel.append(lnk);
				}
				// Generate "Previous"-Link
				if(opts.prev_text && (current_page > 0 || opts.prev_show_always)){
					appendItem(current_page-1,{text:opts.prev_text, classes:"prev"});
				}
				// Generate starting points
				if (interval[0] > 0 && opts.num_edge_entries > 0)
				{
					var end = Math.min(opts.num_edge_entries, interval[0]);
					for(var i=0; i<end; i++) {
						appendItem(i);
					}
					if(opts.num_edge_entries < interval[0] && opts.ellipse_text)
					{
						jQuery("<span>"+opts.ellipse_text+"</span>").appendTo(panel);
					}
				}
				// Generate interval links
				for(var i=interval[0]; i<interval[1]; i++) {
					appendItem(i);
				}
				// Generate ending points
				if (interval[1] < np && opts.num_edge_entries > 0)
				{
					if(np-opts.num_edge_entries > interval[1]&& opts.ellipse_text)
					{
						jQuery("<span>"+opts.ellipse_text+"</span>").appendTo(panel);
					}
					var begin = Math.max(np-opts.num_edge_entries, interval[1]);
					for(var i=begin; i<np; i++) {
						appendItem(i);
					}
					
				}
				// Generate "Next"-Link
				if(opts.next_text && (current_page < np-1 || opts.next_show_always)){
					appendItem(current_page+1,{text:opts.next_text, classes:"next"}); //page to load+1, {next text, class}
				}
			} else {
				panel.text('Page 1 of 1');
			}
		} 
		
		// Extract current_page from options
		var current_page = opts.current_page;
		// Create a sane value for maxentries and items_per_page
		maxentries = (!maxentries || maxentries < 0)?1:maxentries;
		opts.items_per_page = (!opts.items_per_page || opts.items_per_page < 0)?1:opts.items_per_page;
		// Store DOM element for easy access from all inner functions
		var panel = jQuery('.pagination');
		// Attach control functions to the DOM element 
		this.selectPage = function(page_id){ pageSelected(page_id);}
		this.prevPage = function(){ 
			if (current_page > 0) {
				pageSelected(current_page - 1);
				return true;
			}
			else {
				return false;
			}
		}
		this.nextPage = function(){ 
			if(current_page < numPages()-1) {
				pageSelected(current_page+1);
				return true;
			}
			else {
				return false;
			}
		}
		// When all initialisation is done, draw the links
		drawLinks();
	});
}