/*!

 * CrossSlide jQuery plugin v0.6.2

 *

 * Copyright 2007-2010 by Tobia Conforto <tobia.conforto@gmail.com>

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License as published by the Free

 * Software Foundation; either version 2 of the License, or (at your option)

 * any later version.

 *

 * This program is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for

 * more details.

 *

 * You should have received a copy of the GNU General Public License along with

 * this program; if not, write to the Free Software Foundation, Inc., 51

 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 */

/* Changelog:

 *

 * 0.6.2  2010-09-29  Added support for rel attribute

 * 0.6.1  2010-08-02  Bugfixes

 * 0.6    2010-07-03  Variant Ken Burns effect

 * 0.5    2010-06-13  Support for animation control and event callbacks

 * 0.4.2  2010-06-07  Bugfix

 * 0.4.1  2010-06-04  Added target option

 * 0.4    2010-05-20  Better error reporting, published on GitHub

 * 0.3.7  2009-05-14  Fixed bug when container div's CSS position is not set

 * 0.3.6  2009-04-16  Added alt option

 * 0.3.5  2009-03-12  Fixed usage of href parameter in 'Ken Burns' mode

 * 0.3.4  2009-03-12  Added shuffle option,

 *                    contrib. by Ralf Santbergen <ralf_santbergen@hotmail.com>

 * 0.3.3  2008-12-14  Added onclick option

 * 0.3.2  2008-11-11  Fixed CSS bugs, contrib. by Erwin Bot <info@ixgcms.nl>

 * 0.3.1  2008-11-11  Better error messages

 * 0.3    2008-10-22  Option to repeat the animation a fixed number of times

 * 0.2    2008-10-15  Linkable images, contrib. by Tim Rainey <tim@zmlabs.com>

 * 0.1.1  2008-09-18  Compatibility with prototype.js

 * 0.1    2008-08-21  Re-released under GPL v2

 * 0.1    2007-08-19  Initial release

 */

(function() {

	var $ = jQuery,

		animate = ($.fn.startAnimation ? 'startAnimation' : 'animate'),

		pause_missing = 'pause plugin missing.';

	// utility to format a string with {0}, {1}... placeholders

	function format(str) {

		for (var i = 1; i < arguments.length; i++)

			str = str.replace(new RegExp('\\{' + (i-1) + '}', 'g'), arguments[i]);

		return str;

	}

	// utility to abort with a message to the error console

	function abort() {

		arguments[0] = 'CrossSlide: ' + arguments[0];

		throw new Error(format.apply(null, arguments));

	}

	// utility to parse "from" and "to" parameters

	function parse_position_param(param) {

		var zoom = 1;

		var tokens = param.replace(/^\s*|\s*$/g, '').split(/\s+/);

		if (tokens.length > 3) throw new Error();

		if (tokens[0] == 'center')

			if (tokens.length == 1)

				tokens = ['center', 'center'];

			else if (tokens.length == 2 && tokens[1].match(/^[\d.]+x$/i))

				tokens = ['center', 'center', tokens[1]];

		if (tokens.length == 3)

			zoom = parseFloat(tokens[2].match(/^([\d.]+)x$/i)[1]);

		var pos = tokens[0] + ' ' + tokens[1];

		if (pos == 'left top' || pos == 'top left')

			return { xrel: 0, yrel: 0, zoom: zoom };

		if (pos == 'left center' || pos == 'center left')

			return { xrel: 0, yrel: .5, zoom: zoom };

		if (pos == 'left bottom' || pos == 'bottom left')

			return { xrel: 0, yrel: 1, zoom: zoom };

		if (pos == 'center top' || pos == 'top center')

			return { xrel: .5, yrel: 0, zoom: zoom };

		if (pos == 'center center')

			return { xrel: .5, yrel: .5, zoom: zoom };

		if (pos == 'center bottom' || pos == 'bottom center')

			return { xrel: .5, yrel: 1, zoom: zoom };

		if (pos == 'right top' || pos == 'top right')

			return { xrel: 1, yrel: 0, zoom: zoom };

		if (pos == 'right center' || pos == 'center right')

			return { xrel: 1, yrel: .5, zoom: zoom };

		if (pos == 'right bottom' || pos == 'bottom right')

			return { xrel: 1, yrel: 1, zoom: zoom };

		return {

			xrel: parseInt(tokens[0].match(/^(\d+)%$/)[1]) / 100,

			yrel: parseInt(tokens[1].match(/^(\d+)%$/)[1]) / 100,

			zoom: zoom

		};

	}

	$.fn.crossSlide = function(opts, plan, callback)

	{

		var self = this,

				self_width = this.width(),

				self_height = this.height();

		// must be called on exactly 1 element

		if (self.length != 1)

			abort('crossSlide() must be called on exactly 1 element')

		// saving params for crossSlide.restart

		self.get(0).crossSlideArgs = [ opts, plan, callback ];

		// make working copy of plan

		plan = $.map(plan, function(p) {

			return $.extend({}, p);

		});

		// options with default values

		if (! opts.easing)

			opts.easing = opts.variant ? 'swing' : 'linear';

		if (! callback)

			callback = function() {};

		// first preload all the images, while getting their actual width and height

		(function(proceed) {

			var n_loaded = 0;

			function loop(i, img) {

				// this loop is a for (i = 0; i < plan.length; i++)

				// with independent var i, img (for the onload closures)

				img.onload = function(e) {

					n_loaded++;

					plan[i].width = img.width;

					plan[i].height = img.height;

					if (n_loaded == plan.length)

						proceed();

				}

				img.src = plan[i].src;

				if (i + 1 < plan.length)

					loop(i + 1, new Image());

			}

			loop(0, new Image());

		})(function() { // then proceed

			// check global params

			if (! opts.fade)

				abort('missing fade parameter.');

			if (opts.speed && opts.sleep)

				abort('you cannot set both speed and sleep at the same time.');

			// conversion from sec to ms; from px/sec to px/ms

			var fade_ms = Math.round(opts.fade * 1000);

			if (opts.sleep)

				var sleep = Math.round(opts.sleep * 1000);

			if (opts.speed)

				var speed = opts.speed / 1000,

						fade_px = Math.round(fade_ms * speed);

			// set container css

			self.empty().css({

				overflow: 'hidden',

				padding: 0

			});

			if (! /^(absolute|relative|fixed)$/.test(self.css('position')))

				self.css({ position: 'relative' });

			if (! self.width() || ! self.height())

				abort('container element does not have its own width and height');

			// random sorting

			if (opts.shuffle)

				plan.sort(function() {

					return Math.random() - 0.5;

				});

			// prepare each image

			for (var i = 0; i < plan.length; ++i) {

				var p = plan[i];

				if (! p.src)

					abort('missing src parameter in picture {0}.', i + 1);

				if (speed) { // speed/dir mode

					// check parameters and translate speed/dir mode into full mode

					// (from/to/time)

					switch (p.dir) {

						case 'up':

							p.from = { xrel: .5, yrel: 0, zoom: 1 };

							p.to = { xrel: .5, yrel: 1, zoom: 1 };

							var slide_px = p.height - self_height - 2 * fade_px;

							break;

						case 'down':

							p.from = { xrel: .5, yrel: 1, zoom: 1 };

							p.to = { xrel: .5, yrel: 0, zoom: 1 };

							var slide_px = p.height - self_height - 2 * fade_px;

							break;

						case 'left':

							p.from = { xrel: 0, yrel: .5, zoom: 1 };

							p.to = { xrel: 1, yrel: .5, zoom: 1 };

							var slide_px = p.width - self_width - 2 * fade_px;

							break;

						case 'right':

							p.from = { xrel: 1, yrel: .5, zoom: 1 };

							p.to = { xrel: 0, yrel: .5, zoom: 1 };

							var slide_px = p.width - self_width - 2 * fade_px;

							break;

						default:

							abort('missing or malformed dir parameter in picture {0}.', i+1);

					}

					if (slide_px <= 0)

						abort('impossible animation: either picture {0} is too small or '

							+ 'div is too large or fade duration too long.', i + 1);

					p.time_ms = Math.round(slide_px / speed);

				} else if (! sleep) { // full mode

					// check and parse parameters

					if (! p.from || ! p.to || ! p.time)

						abort('missing either speed/sleep option, or from/to/time params '

							+ 'in picture {0}.', i + 1);

					try {

						p.from = parse_position_param(p.from)

					} catch (e) {

						abort('malformed "from" parameter in picture {0}.', i + 1);

					}

					try {

						p.to = parse_position_param(p.to)

					} catch (e) {

						abort('malformed "to" parameter in picture {0}.', i + 1);

					}

					if (! p.time)

						abort('missing "time" parameter in picture {0}.', i + 1);

					p.time_ms = Math.round(p.time * 1000)

				}

				// precalculate left/top/width/height bounding values

				if (p.from)

					$.each([ p.from, p.to ], function(i, each) {

						each.width = Math.round(p.width * each.zoom);

						each.height = Math.round(p.height * each.zoom);

						each.left = Math.round((self_width - each.width) * each.xrel);

						each.top = Math.round((self_height - each.height) * each.yrel);

					});

				// append the image (or anchor) element to the container

				var img, elm;

				elm = img = $(format('<img src="{0}"/>', p.src));

				if (p.href)

					elm = $(format('<a href="{0}"></a>', p.href)).append(img);

				if (p.onclick)

					elm.click(p.onclick);

				if (p.alt)

					img.attr('alt', p.alt);

				if (p.rel)

					elm.attr('rel', p.rel);

				if (p.href && p.target)

					elm.attr('target', p.target);

				elm.appendTo(self);

			}

			delete speed; // speed mode has now been translated to full mode

			// utility to compute the css for a given phase between p.from and p.to

			// 0: begin fade-in, 1: end fade-in, 2: begin fade-out, 3: end fade-out

			function position_to_css(p, phase) {

				var pos = [ 0, fade_ms / (p.time_ms + 2 * fade_ms),

					1 - fade_ms / (p.time_ms + 2 * fade_ms), 1 ][phase];

				return {

					left: Math.round(p.from.left + pos * (p.to.left - p.from.left)),

					top: Math.round(p.from.top + pos * (p.to.top - p.from.top)),

					width: Math.round(p.from.width + pos * (p.to.width - p.from.width)),

					height: Math.round(p.from.height + pos * (p.to.height-p.from.height))

				};

			}

			// find images to animate and set initial css attributes

			var imgs = self.find('img').css({

				position: 'absolute',

				visibility: 'hidden',

				top: 0,

				left: 0,

				border: 0

			});

			// show first image

			imgs.eq(0).css({ visibility: 'visible' });

			if (! sleep)

				imgs.eq(0).css(position_to_css(plan[0], opts.variant ? 0 : 1));

			// create animation chain

			var countdown = opts.loop;

			function create_chain(i, chainf) {

				// building the chain backwards, or inside out

				if (i % 2 == 0) {

					if (sleep) {

						// single image sleep

						var i_sleep = i / 2,

								i_hide = (i_sleep - 1 + plan.length) % plan.length,

								img_sleep = imgs.eq(i_sleep),

								img_hide = imgs.eq(i_hide);

						var newf = function() {

							callback(i_sleep, img_sleep.get(0));

							img_hide.css('visibility', 'hidden');

							setTimeout(chainf, sleep);

						};

					} else {

						// single image animation

						var i_slide = i / 2,

								i_hide = (i_slide - 1 + plan.length) % plan.length,

								img_slide = imgs.eq(i_slide),

								img_hide = imgs.eq(i_hide),

								time = plan[i_slide].time_ms,

								slide_anim = position_to_css(plan[i_slide],

									opts.variant ? 3 : 2);

						var newf = function() {

							callback(i_slide, img_slide.get(0));

							img_hide.css('visibility', 'hidden');

							img_slide[animate](slide_anim, time, opts.easing, chainf);

						};

					}

				} else {

					// double image animation

					var i_from = Math.floor(i / 2),

							i_to = Math.ceil(i / 2) % plan.length,

							img_from = imgs.eq(i_from),

							img_to = imgs.eq(i_to),