$(function()
{
    $.fn.animation_count_to = function (options)
    {
        options = options || {};
        return $(this).each(function () {
            // set options for current element
            var settings = $.extend({}, $.fn.animation_count_to.defaults, {
                from:            $(this).data('from'),
                to:              $(this).data('to'),
                speed:           $(this).data('speed'),
                refreshInterval: $(this).data('refresh-interval'),
                decimals:        $(this).data('decimals')
            }, options);
            
            // how many times to update the value, and how much to increment the value on each update
            var loops = Math.ceil(settings.speed / settings.refreshInterval),
                increment = (settings.to - settings.from) / loops;
            
            // references & variables that will change with each update
            var self = this,
                $self = $(this),
                loopCount = 0,
                value = settings.from,
                data = $self.data('animation_count_to') || {};
            
            $self.data('animation_count_to', data);
            
            // if an existing interval can be found, clear it first
            if (data.interval) {
                clearInterval(data.interval);
            }
            data.interval = setInterval(updateTimer, settings.refreshInterval);
            
            // initialize the element with the starting value
            render(value);
            
            function updateTimer() {
                value += increment;
                loopCount++;
                
                render(value);
                
                if (typeof(settings.onUpdate) == 'function') {
                    settings.onUpdate.call(self, value);
                }
                
                if (loopCount >= loops) {
                    // remove the interval
                    $self.removeData('animation_count_to');
                    clearInterval(data.interval);
                    value = settings.to;
                    
                    if (typeof(settings.onComplete) == 'function') {
                        settings.onComplete.call(self, value);
                    }
                }
            }
            
            function render(value) {
                var formattedValue = settings.formatter.call(self, value, settings);
                $self.html(formattedValue);
            }
        });
    };
        
    $.fn.animation_count_to.defaults = {
        from: 0,               // the number the element should start at
        to: 0,                 // the number the element should end at
        speed: 1000,           // how long it should take to count between the target numbers
        refreshInterval: 100,  // how often the element should be updated
        decimals: 0,           // the number of decimal places to show
        formatter: formatter,  // handler for formatting the value before rendering
        onUpdate: null,        // callback method for every time the element is updated
        onComplete: null       // callback method for when the element finishes updating
    };

    function formatter(value, settings) {
        return value.toFixed(settings.decimals);
    }

    // start all the timers
    $('.animation-count-to').each(function(options) {
        var $this = $(this);
        options = $.extend({}, options || {}, $this.data('animation_count_to_options') || {});
        $this.animation_count_to(options);
    });
});