/*  Snowfall jquery plugin

	Version 1.4 Dec 8th 2010
	Fixed issues (I hope) with scroll bars flickering due to snow going over the edge of the screen. 
	Added round snowflakes via css, will not work for any version of IE. - Thanks to Luke Barker of http://www.infinite-eye.com/
	Added shadows as an option via css again will not work with IE. The idea behind shadows, is to show flakes on lighter colored web sites - Thanks Yutt
 
	Version 1.3.1 Nov 25th 2010
	Updated script that caused flakes not to show at all if plugin was initialized with no options, also added the fixes that Han Bongers suggested 
	
	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,
	round, 		true or false, makes the snowflakes rounded if the browser supports it.
	shadow		true or false, gives the snowflakes a shadow if the browser supports it.
	
	Example Usage :
	$(document).snowfall({flakeCount : 100, maxSpeed : 10});
	
	-or-
	
	$('#element').snowfall({flakeCount : 800, maxSpeed : 5, maxSize : 5});
	
	-or with defaults-
	
	$(document).snowfall();
	
	- To clear -
	$('#element').snowfall('clear');
*/

(function ($) {
    $.snowfall = function (element, options) {
        var defaults = {
            flakeCount: 35,
            flakeColor: '#ffffff',
            flakeIndex: 999999,
            minSize: 1,
            maxSize: 3,
            minSpeed: 2,
            maxSpeed: 3,
            round: false,
            shadow: false
        },
			options = $.extend(defaults, options),
			random = function random(min, max) {
			    return Math.round(min + Math.random() * (max - min));
			};

        $(element).data("snowfall", this);

        // Snow flake object
        function Flake(_x, _y, _size, _speed, _id) {
            // Flake properties
            this.id = _id;
            this.x = _x;
            this.y = _y;
            this.size = _size;
            this.speed = _speed;
            this.step = 0,
				this.stepSize = random(1, 10) / 100;

            var flakeMarkup = $(document.createElement("div")).attr({ 'class': 'snowfall-flakes', 'id': 'flake-' + this.id }).css({ 'width': this.size, 'height': this.size, 'background': options.flakeColor, 'position': 'absolute', 'top': this.y, 'left': this.x, 'fontSize': 0, 'zIndex': options.flakeIndex });

            if ($(element).get(0).tagName === $(document).get(0).tagName) {
                $('body').append(flakeMarkup);
                element = $('body');
            } 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) - (this.size + 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) - widthOffset || this.x < widthOffset) {
                    this.reset();
                }
            }

            // Resets the snowflake once it reaches one of the bounds set
            this.reset = function () {
                this.y = 0;
                this.x = random(widthOffset, elWidth - widthOffset);
                this.stepSize = random(1, 10) / 100;
                this.size = random((options.minSize * 100), (options.maxSize * 100)) / 100;
                this.speed = random(options.minSpeed, options.maxSpeed);
            }
        }

        // Private vars
        var flakes = [],
				flakeId = 0,
				i = 0,
				elHeight = $(element).height(),
				elWidth = $(element).width(),
				widthOffset = 0,
				snowTimeout = 0;

        // This will reduce the horizontal scroll bar from displaying, when the effect is applied to the whole page
        if ($(element).get(0).tagName === $(document).get(0).tagName) {
            widthOffset = 25;
        }

        // 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 = flakes.length;
            flakes.push(new Flake(random(widthOffset, elWidth - widthOffset), random(0, elHeight), random((options.minSize * 100), (options.maxSize * 100)) / 100, random(options.minSpeed, options.maxSpeed), flakeId));
        }

        // This adds the style to make the snowflakes round via border radius property 
        if (options.round) {
            $('.snowfall-flakes').css({ '-moz-border-radius': options.maxSize, '-webkit-border-radius': options.maxSize, 'border-radius': options.maxSize });
        }

        // This adds shadows just below the snowflake so they pop a bit on lighter colored web pages
        if (options.shadow) {
            $('.snowfall-flakes').css({ '-moz-box-shadow': '1px 1px 1px #555', '-webkit-box-shadow': '1px 1px 1px #555', 'box-shadow': '1px 1px 1px #555' });
        }

        // this controls flow of the updating snow
        function snow() {
            for (i = 0; i < flakes.length; i += 1) {
                flakes[i].update();
            }

            snowTimeout = setTimeout(function () { snow() }, 30);
        }

        snow();

        // Public Methods

        // clears the snowflakes
        this.clear = function () {
            $(element).children('.snowfall-flakes').remove();
            flakes = [];
            clearTimeout(snowTimeout);
        };
    };

    // Initialize the options and the plugin
    $.fn.snowfall = function (options) {
        if (typeof (options) == "object" || options == undefined) {
            return this.each(function (i) {
                (new $.snowfall(this, options));
            });
        } else if (typeof (options) == "string") {
            return this.each(function (i) {
                var snow = $(this).data('snowfall');
                if (snow) {
                    snow.clear();
                }
            });
        }
    };
})(jQuery);