/**
 * Galleria (http://monc.se/kitchen)
 *
 * Galleria is a javascript image gallery written in jQuery. 
 * It loads the images one by one from an unordered list and displays thumbnails when each image is loaded. 
 * It will create thumbnails for you if you choose so, scaled or unscaled, 
 * centered and cropped inside a fixed thumbnail box defined by CSS.
 * 
 * The core of Galleria lies in it's smart preloading behaviour, snappiness and the fresh absence 
 * of obtrusive design elements. Use it as a foundation for your custom styled image gallery.
 *
 * Tested in Safari 3, Firefox 2, MSIE 6, MSIE 7, Opera 9
 * 
 * Version 1.0
 * Februari 21, 2008
 *
 * Copyright (c) 2008 David Hellsing (http://monc.se)
 * Licensed under the GPL licenses.
 * http://www.gnu.org/licenses/gpl.txt
 **/

;(function($){

var $$;


/**
 * 
 * @desc Convert images from a simple html <ul> into a thumbnail gallery
 * @author David Hellsing
 * @version 1.0
 *
 * @name Galleria
 * @type jQuery
 *
 * @cat plugins/Media
 * 
 * @example $('ul.gallery').galleria({options});
 * @desc Create a a gallery from an unordered list of images with thumbnails
 * @options
 *   insert:   (selector string) by default, Galleria will create a container div before your ul that holds the image.
 *             You can, however, specify a selector where the image will be placed instead (f.ex '#main_img')
 *   onImage:  (function) a function that gets fired when the image is displayed and brings the jQuery image object.
 *             You can use it to add click functionality and effects.
 *             f.ex onImage(image) { image.css('display','none').fadeIn(); } will fadeIn each image that is displayed
 *   onThumb:  (function) a function that gets fired when the thumbnail is displayed and brings the jQuery thumb object.
 *             Works the same as onImage except it targets the thumbnail after it's loaded.
 *   nextPage: (function) a function that gets called when going to the next picture from the last in the list. If not 
 *             specified, the gallery goes back to the first image.
 *   prevPage: (function) a function that gets called when going to the previous picture from the first in the list. If not 
 *             specified, the gallery goes back to the last image.
 *
**/

$$ = $.fn.galleria = function($options) {
    
    // check for basic CSS support
    if (!$$.hasCSS()) { return false; }
    
    // set default options
    var $defaults = {
        mainImage   : '.galleria_container',
        clickNext   : true,
        onImage     : function(image,caption,thumb) {},
        onThumb     : function(thumb) {},
        nextPage    : null,
        prevPage    : null
    };
    

    // extend the options
    var $opts = $.extend($defaults, $options);
    
    // bring the options to the galleria object
    for (var i in $opts) {
        $.galleria[i]  = $opts[i];
    }
    
    // if no insert selector, create a new division and insert it before the ul
    var _insert = ( $($opts.mainImage).is($opts.mainImage) ) ? 
        $($opts.mainImage) : 
        jQuery(document.createElement('div')).insertBefore(this);
        
    // create a wrapping div for the image
    var _div = $(document.createElement('div')).addClass('galleria_wrapper');
    
    // create a caption div
    var _captionDiv = $(document.createElement('div')).addClass('caption');
    
    // inject the wrapper in in the insert selector
    _insert.addClass('galleria_container').append(_div).append(_captionDiv);
    
    //-------------
    
    return this.each(function(){
        
        // add the Galleria class
        $(this).addClass('galleria');
        
        // loop through list
        $(this).children('li').each(function(i) {
            
            // bring the scope
            var _container = $(this);
                            
            // build element specific options
            var _o = $.meta ? $.extend({}, $opts, _container.data()) : $opts;
            
            // remove the clickNext if image is only child
            _o.clickNext = $(this).is(':only-child') ? false : _o.clickNext;
            
            // try to fetch an anchor
            var _a = $(this).find('a').is('a') ? $(this).find('a') : false;
            
            // reference the original image as a variable and hide it
            var _img = $(this).children('img').css('display','none');
            
            // extract the original source
            var _src = _a ? _a.attr('href') : _img.attr('src');
            
            // find a title
            var _title = _img.attr('title');
            
            // find a caption
            var _caption = _a ? _a.attr('title') : _img.attr('title');
            
            // create loader image            
            var _loader = new Image();
            
            // begin loader
            $(_loader).load(function () {
                
                // try to bring the alt
                $(this).attr('alt',_img.attr('alt'));
                
                //-----------------------------------------------------------------
                // the image is loaded, let's create the thumbnail
                
                var _thumb = _a ? 
                    _a.find('img').addClass('thumb').css('display','none') :
                    _img.clone(true).addClass('thumb').css('display','none');
                
                if (_a) { _a.replaceWith(_thumb); }
                
                if (!_thumb.hasClass('noscale')) { // scaled tumbnails!
                    //window.setTimeout(function() {
                        var w = Math.ceil( _thumb.width() / _thumb.height() * _container.height() );
                        var h = Math.ceil( _thumb.height() / _thumb.width() * _container.width() );
                        if (w < h) {
                            _thumb.css({ height: 'auto', width: _container.width(), marginTop: -(h-_container.height())/2 });
                        } else {
                            _thumb.css({ width: 'auto', height: _container.height(), marginLeft: -(w-_container.width())/2 });
                        }
                    //}, 1);
                } else { // Center thumbnails.
                    // a tiny timer fixed the width/height
                    window.setTimeout(function() {
                        _thumb.css({
                            marginLeft: -( _thumb.width() - _container.width() )/2, 
                            marginTop:  -( _thumb.height() - _container.height() )/2
                        });
                    }, 1);
                }
                
                // add the rel attribute
                _thumb.attr('rel',_src);
                
                // add the title attribute
                _thumb.attr('title',_title);
                
                // add the caption attribute
                _thumb.attr('caption',_caption);
                
                // add the click functionality to the _thumb
                _thumb.click(function() {
                    $.galleria.activate(_src);
                });
                
                // hover classes for IE6
                _thumb.hover(
                    function() { $(this).addClass('hover'); },
                    function() { $(this).removeClass('hover'); }
                );
                _container.hover(
                    function() { _container.addClass('hover'); },
                    function() { _container.removeClass('hover'); }
                );

                // prepend the thumbnail in the container
                _container.prepend(_thumb);
                
                // show the thumbnail
                _thumb.css('display','block');
                
                // call the onThumb function
                _o.onThumb(jQuery(_thumb));
                
                // check active class and activate image if match
                if (_container.hasClass('active')) {
                    $.galleria.activate(_src);
                    //_captionDiv.text(_title);
                }
                
                //-----------------------------------------------------------------
                
                // finally delete the original image
                _img.remove();
                
            }).error(function () {
                
                // Error handling
                _container.html('<span class="error" style="color:red">Error loading image: '+_src+'</span>');
            
            }).attr('src', _src);
        });
    });
};

/**
 *
 * @name NextSelector
 *
 * @desc Returns the sibling sibling, or the first one
 *
**/

$$.nextSelector = function(selector) {
    return $(selector).is(':last-child') ?
           $(selector).siblings(':first-child') :
           $(selector).next();
           
};

/**
 *
 * @name previousSelector
 *
 * @desc Returns the previous sibling, or the last one
 *
**/

$$.previousSelector = function(selector) {
    return $(selector).is(':first-child') ?
           $(selector).siblings(':last-child') :
           $(selector).prev();
           
};

/**
 *
 * @name hasCSS
 *
 * @desc Checks for CSS support and returns a boolean value
 *
**/

$$.hasCSS = function()  {
    $('body').append(
        $(document.createElement('div')).attr('id','css_test')
        .css({ width:'1px', height:'1px', display:'none' })
    );
    var _v = ($('#css_test').width() != 1) ? false : true;
    $('#css_test').remove();
    return _v;
};

/**
 *
 * @name onPageLoad
 *
 * @desc The function that displays the image and alters the active classes
 *
**/

$$.onPageLoad = function(_src) {    
    
    // get the wrapper
    var _wrapper = $('.galleria_wrapper');
    
    // get the thumb
    var _thumb = $('.galleria img[rel="'+_src+'"]');
    
    if (_src) {
        
        // alter the active classes
        _thumb.parents('li').siblings('.active').removeClass('active');
        _thumb.parents('li').addClass('active');
    
        // define a new image
        var _img = $(new Image()).attr('src',_src).addClass('replaced');

        // empty the wrapper and insert the new image
        _wrapper.empty().append(_img);

        // insert the caption
        _wrapper.siblings('.caption').html(_thumb.attr('caption'));
        
        // fire the onImage function to customize the loaded image's features
        $.galleria.onImage(_img,_wrapper.siblings('.caption'),_thumb);
        
        // add clickable image helper
        if($.galleria.clickNext) {
            _img.css('cursor','pointer').click(function() { $.galleria.next(); })
        }
        
    } else {
        
        // clean up the container if none are active
        _wrapper.siblings().andSelf().empty();
        
        // remove active classes
        $('.galleria li.active').removeClass('active');
    }

    // place the source in the galleria.current variable
    $.galleria.current = _src;
    
}

/**
 *
 * @name jQuery.galleria
 *
 * @desc The global galleria object holds four constant variables and four public methods:
 *       $.galleria.current = is the current source that's being viewed.
 *       $.galleria.clickNext = boolean helper for adding a clickable image that leads to the next one in line
 *       $.galleria.next() = displays the next image in line, returns to first image after the last.
 *       $.galleria.prev() = displays the previous image in line, returns to last image after the first.
 *       $.galleria.activate(_src) = displays an image from _src in the galleria container.
 *       $.galleria.onImage(image,caption) = gets fired when the image is displayed.
 *
**/

$.extend({galleria : {
    current : '',
    onImage : function(){},
    activate : function(_src) { 
        $$.onPageLoad(_src);
    },
    next : function() {
        var _current = $('.galleria img[rel="'+$.galleria.current+'"]').parents('li');
        if(!$(_current).is(':last-child') || $.galleria.nextPage == null) {
            var _next = $($$.nextSelector(_current)).find('img').attr('rel');
            $.galleria.activate(_next);
        }
        else {
            $.galleria.nextPage();
        }
    },
    prev : function() {
        var _current = $('.galleria img[rel="'+$.galleria.current+'"]').parents('li');
        if(!$(_current).is(':first-child') || $.galleria.prevPage == null) {
            var _prev = $($$.previousSelector(_current)).find('img').attr('rel');
            $.galleria.activate(_prev);
        }
        else {
            $.galleria.prevPage();
        }
    }
}
});

})(jQuery);