/**
 * Overlay Gallery plugin, version: 1.0.0
 *
 * Copyright (c) 2009 Tero Piirainen
 * http://flowplayer.org/tools/overlay.html#gallery
 *
 * Dual licensed under MIT and GPL 2+ licenses
 * http://www.opensource.org/licenses
 *
 * Since  : July 2009
 * Date: ${date}
 * Revision: ${revision}
 */
(function($) {

	// TODO: next(), prev(), getIndex(), onChange event

	// version number
	var t = $.tools.overlay;
	t.plugins = t.plugins || {};

	t.plugins.gallery = {
		version: '1.0.0',
		conf: {
			imgId: 'img',
			next: '.next',
			prev: '.prev',
			info: '.info',
			progress: '.progress',
			disabledClass: 'disabled',
			activeClass: 'active',
			opacity: 0.8,
			speed: 'slow',
			template: '<strong>${title}</strong> <span>картинка ${index} из ${total}</span>',
			autohide: true,
			preload: true,
			api: false
		}
	};

	$.fn.gallery = function(opts) {

		var conf = $.extend({}, t.plugins.gallery.conf), api;
		$.extend(conf, opts);

		// common variables for all gallery images
		api = this.overlay();

		var links = this,
			 overlay = api.getOverlay(),
			 next = overlay.find(conf.next),
			 prev = overlay.find(conf.prev),
			 info = overlay.find(conf.info),
			 progress = overlay.find(conf.progress),
			 els = prev.add(next).add(info).css({opacity: conf.opacity}),
			 close = api.getClosers(),
			 index;


//{{{ load

		function load(el) {

			progress.fadeIn();
			els.hide(); close.hide();

			var url = el.attr("href");

			// download the image
			var image = new Image();

			image.onload = function() {

				progress.fadeOut();

				// find image inside overlay
				var img = $("#" + conf.imgId, overlay);

				// or append it to the overlay
				if (!img.length) {
					img = $("<img/>").attr("id", conf.imgId).css("visibility", "hidden");
					overlay.prepend(img);
				}

				// make initially invisible to get it's dimensions
				img.attr("src", url).css("visibility", "hidden");

				// animate overlay to fit the image dimensions
				var width = image.width;
				var left = ($(window).width() - width) / 2;

				// calculate index number
				index = links.index(links.filter("a[href=" +url+ "]"));

				// activate trigger
				links.removeClass(conf.activeClass).eq(index).addClass(conf.activeClass);

				// enable/disable next/prev links
				var cls = conf.disabledClass;
				els.removeClass(cls);

				if (index === 0) { prev.addClass(cls); }
				if (index == links.length -1) { next.addClass(cls); }


				// set info text & width
				var text = conf.template
					.replace("${title}", el.attr("title") || el.data("title"))
					.replace("${index}", index + 1)
					.replace("${total}", links.length);

				var padd = parseInt(info.css("paddingLeft"), 10) +  parseInt(info.css("paddingRight"), 10);
				info.html(text).css({width: width - padd});

				overlay.animate({
					width: width, height: image.height, left: left}, conf.speed, function() {

					// gradually show the image
					img.hide().css("visibility", "visible").fadeIn(function() {
						if (!conf.autohide) {
							els.fadeIn(); close.show();
						}
					});

				});
			};

			image.onerror = function() {
				overlay.fadeIn().html("Cannot find image " + url);
			};

			image.src = url;

			if (conf.preload) {
				links.filter(":eq(" +(index-1)+ "), :eq(" +(index+1)+ ")").each(function()  {
					var img = new Image();
					img.src = $(this).attr("href");
				});
			}

		}

//}}}


		// function to add click handlers to next/prev links
		function addClick(el, isNext)  {

			el.click(function() {

				if (el.hasClass(conf.disabledClass)) { return; }

				// find the triggering link
				var trigger = links.eq(i = index + (isNext ? 1 : -1));

				// if found load it's href
				if (trigger.length) { load(trigger); }

			});
		}

		// assign next/prev click handlers
		addClick(next, true);
		addClick(prev);


		// arrow keys
		$(document).keydown(function(evt) {

			if (!overlay.is(":visible") || evt.altKey || evt.ctrlKey) { return; }

			if (evt.keyCode == 37 || evt.keyCode == 39) {
				var btn = evt.keyCode == 37 ? prev : next;
				btn.click();
				return evt.preventDefault();
			}
			return true;
		});

		function showEls() {
			if (!overlay.is(":animated")) {
				els.show(); close.show();
			}
		}

		// autohide functionality
		if (conf.autohide) {
			overlay.hover(showEls, function() { els.fadeOut();	close.hide(); }).mousemove(showEls);
		}

		// load a proper gallery image when overlay trigger is clicked
		var ret;

		this.each(function() {

			var el = $(this), api = $(this).overlay(), ret = api;

			api.onBeforeLoad(function() {
				load(el);
			});

			api.onClose(function() {
				links.removeClass(conf.activeClass);
			});
		});

		return conf.api ? ret : this;

	};

})(jQuery);