/*
Copyright (c) 2008, http://seyfertdesign.com/jquery/ui-tabs-paging.html

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

var initialized = false;
$.extend($.ui.tabs.prototype, {
	paging: function(options) {
		var opts = {
			tabsPerPage: 0,
			nextButton: '»',
			prevButton: '«',
			follow: false,
			cycle: false
		};
		
		opts = jQuery.extend(opts, options);

		var self = this, initialized = false, currentPage, 
			buttonWidth, containerWidth, allTabsWidth, tabWidths, 
			maxPageWidth, pages, resizeTimer = null, 
			windowHeight = $(window).height(), windowWidth = $(window).width();
				
		function init() {
			allTabsWidth = 0, currentPage = 0, maxPageWidth = 0, buttonWidth = 0,
				pages = new Array(), tabWidths = new Array(), selectedTabWidths = new Array();
			
			containerWidth = $(self.element).width();
			
			// create next button			
			$li = $('<li></li>')
				.addClass('ui-tabs-paging-next');
			$a = $('<a href="#"></a>')
				.click(function() { page('next'); return false; })
				.html(opts.nextButton);
			$li.append($a);
			
			self.$lis.eq(self.length()-1).after($li);
			buttonWidth = $li.outerWidth({ margin: true });
			
			// create prev button
			$li = $('<li></li>')
				.addClass('ui-tabs-paging-prev');
			$a = $('<a href="#"></a>')
				.click(function() { page('prev'); return false; })
				.html(opts.prevButton);
			$li.append($a);
			self.$lis.eq(0).before($li);
			buttonWidth += $li.outerWidth({ margin: true });
			
			// loops through LIs, get width of each tab when selected and unselected.
			self.$lis.each(function(i) {			
				if (i == self.options.selected) {
					selectedTabWidths[i] = $(this).outerWidth({ margin: true });
					tabWidths[i] = self.$lis.eq(i).removeClass('ui-tabs-selected').outerWidth({ margin: true });
					self.$lis.eq(i).addClass('ui-tabs-selected');
					allTabsWidth += selectedTabWidths[i];					
				} else {
					tabWidths[i] = $(this).outerWidth({ margin: true });
					selectedTabWidths[i] = self.$lis.eq(i).addClass('ui-tabs-selected').outerWidth({ margin: true });
					self.$lis.eq(i).removeClass('ui-tabs-selected');
					allTabsWidth += tabWidths[i];
				}
			});
			
			// if the width of all tables is greater than the container's width, calculate the pages
			if (allTabsWidth > containerWidth) {
				var pageIndex = 0, pageWidth = 0, maxTabPadding = 0;
				
				// start calculating pageWidths
				for (var i = 0; i < tabWidths.length; i++) {
					// if first tab of page or selected tab's padding larger than the current max, set the maxTabPadding
					if (pageWidth == 0 || selectedTabWidths[i] - tabWidths[i] > maxTabPadding)
						maxTabPadding = (selectedTabWidths[i] - tabWidths[i]);
					
					// if first tab of page, initialize pages variable for page 
					if (pages[pageIndex] == null) {
						pages[pageIndex] = { start: i };
					
					} else if ((i > 0 && (i % opts.tabsPerPage) == 0) || (tabWidths[i] + pageWidth + buttonWidth + 12) > containerWidth) {
						if ((pageWidth + maxTabPadding) > maxPageWidth)	
							maxPageWidth = (pageWidth + maxTabPadding);
						pageIndex++;
						pages[pageIndex] = { start: i };			
						pageWidth = 0;
					}
					pages[pageIndex].end = i+1;
					pageWidth += tabWidths[i];
					if (i == self.options.selected) currentPage = pageIndex;
				}
				if ((pageWidth + maxTabPadding) > maxPageWidth)	
					maxPageWidth = (pageWidth + maxTabPadding);				

			    // hide all tabs then show tabs for current page
				self.$lis.hide().slice(pages[currentPage].start, pages[currentPage].end).show();
				if (currentPage == (pages.length - 1) && !opts.cycle) 
					disableButton('next');			
				if (currentPage == 0 && !opts.cycle) 
					disableButton('prev');
				
				// calculate the right padding for the next button
				buttonPadding = containerWidth - maxPageWidth - buttonWidth - ($.browser.msie?8:0);
				if (buttonPadding > 0) 
					$('.ui-tabs-paging-next', self.element).css({ paddingRight: buttonPadding + 'px' });
				
				initialized = true;
			} else {
				destroy();
			}
			
			$(window).bind('resize', handleResize);
		}
		
		function page(direction) {					
			currentPage = currentPage + (direction == 'prev'?-1:1);
			
			if (direction == 'prev' && currentPage < 0 && opts.cycle)
				currentPage = pages.length - 1;
			else if ((direction == 'prev' && currentPage < 0) || 
			         (direction == 'next' && currentPage >= pages.length))
				currentPage = 0;
			
			var start = pages[currentPage].start;
			var end = pages[currentPage].end;
			self.$lis.hide().slice(pages[currentPage].start, pages[currentPage].end).show();
			
			if (direction == 'prev') {
				enableButton('next');
				if (opts.follow && (self.options.selected < start || self.options.selected > (end-1))) self.select(end-1);
				if (!opts.cycle && start <= 0) disableButton('prev');
			} else {
				enableButton('prev');
				if (opts.follow && (self.options.selected < start || self.options.selected > (end-1))) self.select(start);
				if (!opts.cycle && end >= self.length()) disableButton('next');
			}
		}
		
		function disableButton(direction) {
			$('.ui-tabs-paging-'+direction, self.element).addClass('ui-tabs-paging-disabled');
		}
		
		function enableButton(direction) {
			$('.ui-tabs-paging-'+direction, self.element).removeClass('ui-tabs-paging-disabled');
		}
		
		// special function defined to handle IE6 and IE7 resize issues
		function handleResize() {
			if (resizeTimer) clearTimeout(resizeTimer);
			
			if (windowHeight != $(window).height() || windowWidth != $(window).width()) 
				resizeTimer = setTimeout(reinit, 100);
		}
		
		function reinit() {	
			windowHeight = $(window).height();
			windowWidth = $(window).width();
			destroy();
			init();
		}
		
		function destroy() {	
			// remove buttons
			$('.ui-tabs-paging-next', self.element).remove();
			$('.ui-tabs-paging-prev', self.element).remove();
			
			// show all tabs
			self.$lis.show();
			
			initialized = false;

			$(window).unbind('resize', handleResize);
		}
		
		init();
		
		// add, remove, and destroy functions specific for paging 
		$.extend($.ui.tabs.prototype, {	
			pagingAdd: function(url, label, index) {
				if (initialized) {
					destroy();
					this.add(url, label, index);
					init();
				} else {
					this.add(url, label, index);
				}
			},
			pagingRemove: function(index) {
				if (initialized) {
					destroy();
					this.remove(index);
					init();
				} else 
					this.remove(index);
			},
			pagingDestroy: function() {
				destroy();
			}
		});

	}
});