/*
* jQuery pager plugin
* Version 1.0 (12/22/2008)
* @requires jQuery v1.2.6 or later
*
* Example at: http://jonpauldavies.github.com/JQuery/Pager/PagerDemo.html
*
* Copyright (c) 2008-2009 Jon Paul Davies
* Dual licensed under the MIT and GPL licenses:
* http://www.opensource.org/licenses/mit-license.php
* http://www.gnu.org/licenses/gpl.html
* 
* Read the related blog post and contact the author at http://www.j-dee.com/2008/12/22/jquery-pager-plugin/
*
* This version is far from perfect and doesn't manage it's own state, therefore contributions are more than welcome!
*
* Usage: .pager({ pagenumber: 1, pagecount: 15, buttonClickCallback: PagerClickTest });
*
* Where pagenumber is the visible page number
*       pagecount is the total number of pages to display
*       buttonClickCallback is the method to fire when a pager button is clicked.
*
* buttonClickCallback signiture is PagerClickTest = function(pageclickednumber) 
* Where pageclickednumber is the number of the page clicked in the control.
*
* The included Pager.CSS file is a dependancy but can obviously tweaked to your wishes
* Tested in IE6 IE7 Firefox & Safari. Any browser strangeness, please report.
*/
(function($) {
	$.fn.pager = function(options) {
		var opts = $.extend({}, $.fn.pager.defaults, options);
		return this.each(function() {

			// empty out the destination element and then render out the pager with the supplied options
			$(this).empty().append(renderpager(parseInt(opts.pagenumber), parseInt(opts.pagecount), parseInt(opts.scrollSize), opts.prevText, opts.nextText, opts.firstText, opts.lastText, opts.isFirstVisible, opts.isLastVisible, opts.buttonClickCallback));

			// specify correct cursor activity
			$('.pages li').mouseover(function() { document.body.style.cursor = "pointer"; }).mouseout(function() { document.body.style.cursor = "auto"; });
		});
	};

	// render and return the pager with the supplied options
	function renderpager(pagenumber, pagecount, scrollSize, prevText, nextText, firstText, lastText, isFirstVisible, isLastVisible, buttonClickCallback) {

		// setup $pager to hold render
		var $pager = $('<ul class="pages"></ul>');

		if (scrollSize > pagecount) {
			scrollSize = pagecount;
		}

		// add in the previous and next buttons
		if (isFirstVisible) {
			$pager.append(renderButton(firstText, pagenumber, pagecount, prevText, nextText, firstText, lastText, isFirstVisible, isLastVisible, buttonClickCallback));
		}

		

		$pager.append(renderButton(prevText, pagenumber, pagecount, prevText, nextText, firstText, lastText, isFirstVisible, isLastVisible, buttonClickCallback));

		// pager currently only handles 10 viewable pages ( could be easily parameterized, maybe in next version ) so handle edge cases
		var startPoint = 1;
		var endPoint = scrollSize;
		var halfPoint = parseInt(scrollSize / 2);

		if (pagenumber > halfPoint) {
			startPoint = pagenumber - halfPoint;
			endPoint = pagenumber + halfPoint;
		}

		if (endPoint > pagecount) {
			startPoint = pagecount - (scrollSize - 1);
			endPoint = pagecount;
		}

		if (startPoint < 1) {
			startPoint = 1;
		}

		// loop thru visible pages and render buttons
		for (var page = startPoint; page <= endPoint; page++) {

			var currentButton = $('<li class="page-number">' + (page) + '</li>');

			page == pagenumber ? currentButton.addClass('pgCurrent') : currentButton.click(function() { buttonClickCallback(this.firstChild.data); });
			currentButton.appendTo($pager);
		}

		// render in the next and last buttons before returning the whole rendered control back.
		$pager.append(renderButton(nextText, pagenumber, pagecount, prevText, nextText, firstText, lastText, isFirstVisible, isLastVisible, buttonClickCallback));

		if (isLastVisible) {
			$pager.append(renderButton(lastText, pagenumber, pagecount, prevText, nextText, firstText, lastText, isFirstVisible, isLastVisible, buttonClickCallback));
		}


		return $pager;
	}

	// renders and returns a 'specialized' button, ie 'next', 'previous' etc. rather than a page number button
	function renderButton(buttonLabel, pagenumber, pagecount, prevText, nextText, firstText, lastText, isFirstVisible, isLastVisible, buttonClickCallback) {

		var $Button = $('<li class="pgNext">' + buttonLabel + '</li>');

		var destPage = 1;

		// work out destination page for required button type
		switch (buttonLabel) {
			case firstText:
				destPage = 1;
				break;
			case prevText:
				destPage = pagenumber - 1;
				break;
			case nextText:
				destPage = pagenumber + 1;
				break;
			case lastText:
				destPage = pagecount;
				break;
		}

		// disable and 'grey' out buttons if not needed.
		if (buttonLabel == firstText || buttonLabel == prevText) {
			pagenumber <= 1 ? $Button.addClass('pgEmpty') : $Button.click(function() { buttonClickCallback(destPage); });
		}
		else {
			pagenumber >= pagecount ? $Button.addClass('pgEmpty') : $Button.click(function() { buttonClickCallback(destPage); });
		}

		return $Button;
	}

	// pager defaults. hardly worth bothering with in this case but used as placeholder for expansion in the next version
	$.fn.pager.defaults = {
		pagenumber: 1,
		pagecount: 1,
		scrollSize: 6,
		isFirstVisible: false,
		isLastVisible: false,
		firstText: "first",
		lastText: "last",
		prevText: "<<",
		nextText: ">>"
	};

})(jQuery);