jQuery(function($){

    // addSizes was written by Natalie Downe
    // http://natbat.net/2008/Aug/27/addSizes/

    // Copyright (c) 2008, Natalie Downe under the BSD license
    // http://www.opensource.org/licenses/bsd-license.php

    $('a[href$=".pdf"]').each(function(){
    // $('a[href$=".pdf"], a[href$=".doc"], a[href$=".mp3"], a[href$=".jpg"], a[href$=".png"], a[href$=".swf"], a[href$=".zip"], a[href$=".ogg"], a[href$=".m4u"]').each(function(){
        // looking at the href of the link, if it contains pdf, doc, zip, mp3, ogg, m4u, jpg, png, swf
        var link = $(this);
        var bits = this.href.split('.');
        var type = bits[bits.length -1];

        var url= "http://json-head.appspot.com/?url="+encodeURIComponent (this.href)+"&callback=?";
//        console.log(url);

        // then call the json thing and insert the size back into the link text
        $.getJSON(url, function(json){
            if(json.ok && json.headers['Content-Length']) {
                var length = parseInt(json.headers['Content-Length'], 10);

                // divide the length into its largest unit
                var units = [
                    [1024 * 1024 * 1024, 'GB'],
                    [1024 * 1024, 'MB'],
                    [1024, 'KB'],
                    [1, 'bytes']
                ];

                for(var i = 0; i < units.length; i++){

                    var unitSize = units[i][0];
                    var unitText = units[i][1];

                    if (length >= unitSize) {
                        length = length / unitSize;
                        // 1 decimal place
                        length = Math.ceil(length * 10) / 10;
                        var lengthUnits = unitText;
                        break;
                    }
                }

                // insert the text directly after the link and add a class to the link
                // note: if you want to insert the size into the link rather than after it change the following 'after' to 'append'
                link.append(' (' + type.toUpperCase() + '/' + length + ' ' + lengthUnits + ')');
                link.addClass(type);
            }
        });
    });
});