/*  Snowfall jquery plugin 
    version 1.2, Dec 20 2009
    Developed by Jason Brown for any bugs or questions email me at loktar69@hotmail
    info on the plugin is located on Somethinghitme.com
    
    values for snow options are
    
    flakeCount,
    flakeColor,
    flakeIndex,
    minSize,
    maxSize,
    minSpeed,
    maxSpeed
    
    Example Usage :
    $(document).snowfall({flakeCount : 100, maxSpeed : 10});
    
    -or-
    
    $('#element').snowfall({flakeCount : 800, maxSpeed : 5, maxSize : 5});
    
    -or with defaults-
    
    $(document).snowfall();
*/

(function($){
    $.fn.snowfall = function(options){
        
        var element = this;
        
        // random fuction for generating random vals
        random = function random(min, max){
            return Math.round(min + Math.random()*(max-min)); 
        }
        
        // snow flake class
        function Flake(_x, _y, _size, _speed)
        {
            // Flake properties
            this.id = flakeId; 
            this.x  = _x;
            this.y  = _y;
            this.size = _size;
            this.speed = _speed;
            this.step = 0,
            this.stepSize = random(1,10) / 100;
            
            var flakeMarkup = "<div id='flake-" + this.id + "' style='width: " + this.size + "px; height: " + this.size + "px; background: " + options.flakeColor + "; position: absolute; top: " + this.y + "px; left:" + this.x + "px; font-size: 0px; z-index: " + options.flakeIndex + ";'></div>";
            
            if($(element).get(0).tagName === $(document).get(0).tagName){
                $('body').append(flakeMarkup);
            }else{
                $(element).append(flakeMarkup);
            }
            
            this.element = document.getElementById('flake-' + this.id);
            
            // Update function, used to update the snow flakes, and checks current snowflake against bounds
            this.update = function(){
                this.y += this.speed;
                
                if(this.y > (elHeight) - 6){
                    this.reset();
                }
                
                this.element.style.top = this.y + 'px';
                this.element.style.left = this.x + 'px';
                
                this.step += this.stepSize;
                this.x += Math.cos(this.step);
                
                if(this.x > (elWidth) - 6 || this.x < 6){
                    this.reset();
                }
            }
            
            // Resets the snowflake once it reaches one of the bounds set
            this.reset = function(){
                this.y = 0;
                this.x = random(0, elWidth);
                this.stepSize = random(1,10) / 100;
                this.size = random((options.minSize * 100), (options.maxSize * 100)) / 100;
                this.speed = random(options.minSpeed, options.maxSpeed);
            }
        }
    
        // plugin vars
        var flakes = [],
            flakeId = 0,
            i = 0,
            elHeight = $(element).height(),
            elWidth = $(element).width(),
            defaults = {
                flakeCount : 35,
                flakeColor : '#ffffff',
                flakeIndex: 999999,
                minSize : 2,
                maxSize : 3,
                minSpeed : 2,
                maxSpeed : 3
                },
            options = $.extend(defaults, options);        
        
        // Bind the window resize event so we can get the innerHeight again
        $(window).bind("resize", function(){  
            elHeight = $(element).height();
            elWidth = $(element).width();
        }); 
        

        // initialize the flakes
        for(i = 0; i < options.flakeCount; i+=1){
            flakeId = i;
            flakes[i] = new Flake(random(0,elWidth), random(0, elHeight), random((options.minSize * 100), (options.maxSize * 100)) / 100, random(options.minSpeed, options.maxSpeed));
        }
    
        // this controls flow of the updating snow
        function snow(){
            for( i = 0; i < options.flakeCount; i += 1){
                flakes[i].update();
            }
            
            setTimeout(function(){snow()}, 30);
        }
        
        snow();
    };
})(jQuery);