(function ($) {
    //
    // $.fn.firework
    //
    // Firework plugin
    //
    // Author: Antoine BERNIER (abernier)
    //
    
    var settings;
    
    function firework(el, options) {
        var $stars = $();
        
        //
        // Generate stars markup (within a container)
        //
        
        $(el)
            .css('position', function (index, value) {
                return value === 'static' ? 'relative' : false;
            })
            .append($('<span/>').css({
                position: 'absolute',
                left: 0,
                top: 0,
                right: 0,
                bottom:0
            })
                .append(function () {
                    var i = options.amount;
    
                    while (i--) {
                        $stars = $stars.add(($('<span/>', {
                            "class": options.klass,
                            html: ($.isArray(options.content) ? options.content[random(0, options.content.length - 1)] : options.content)
                        }).css({
                            position: 'absolute',
                            left: '50%',
                            top: '50%'
                        })));
                    }
    
                    return $stars;
                })
            )
        ;
        
        // Once stars into the DOM, use their width/height to apply the negative margin offset
        $stars.each(function (i, el) {
            $(el).css('margin-left', function (index, value) {
                return -($(this).width() / 2);
            }).css('margin-top', function (index, value) {
                return -($(this).height() / 2);
            });
        });
        
        //
        // Animate stars
        //
        
        (function () {
            var animations = [];
            
            $stars.each(function (i, el) {
                animations.push($(el).animate({
                    left: minusOrPlus() + '=' + options.boundary * random(0, 50) + '%',
                    top:  minusOrPlus() + '=' + options.boundary * random(0, 50) + '%',
                    fontSize: random(100, 100 * options.boundary) + '%',
                    opacity: 0
                }, random(~~(options.duration / options.durationVariation), options.duration), options.easing));
            });
            
            $.when.apply(this, animations).done(function () {
                $stars.parent().remove();
            });
        }());
        
        //
        // Helpers
        //
        
        function random(min, max) {
            return Math.floor(Math.random() * (max - min + 1)) + min;
        }
            
        function minusOrPlus() {
            return Math.random() > .5 ? '+' : '-';
        }
    }
    
    // Default settings
    settings = {
        amount: 50,
        boundary: 1.5,
        content: '★',
        klass: 'firework star',
        duration: 3000,
        durationVariation: 3,
        easing: 'swing'
    };
    
    $.fn.firework = function (options) {
        return this.each(function (i, el) {
            firework(el, $.extend({}, settings, options));
        });
    };
}(jQuery));