var parseLinks = function(data) {

    var div = data.match(/<div class="reddit-link .*?><\/div><\/div>/g);

    var href, title, week, diff, lastLink, extra, lastWeek;

​

    for(var i = 0, len = div.length; i < len; i++) {

        href = div[i].match(/href="(.*?)"/)[1];

        title = div[i].match(/href.*>(.*)<\/a><br /)[1]

        extra = title.match(/^(?:\[Monthly |\[Weekly )/i);

        try {

            week = title.match(/Challenge\s*#\s*(\d{1,})/i)[1];

            diff = title.match(/\[Easy]|\[Intermediate]|\[Hard]|\[Difficult]/i)[0];

        }

        catch(e){

            if( extra == null ) {

                console.log('warning: div unhandled\n',href,'\n',title,'\n',div[i]);

                continue;

            }

            week = lastWeek;

            diff = '[Bonus]';

        }

        lastWeek = week;

        diff = diff[0] + diff[1].toUpperCase() + diff.slice(2).toLowerCase();

        if( diff == '[Difficult]' ) diff = '[Hard]';

        weeks[week] || (weeks[week] = {'[Easy]':[],'[Intermediate]':[],'[Hard]':[],'[Bonus]':[]});

        weeks[week][diff].push(' [' + title + '](' + href + ') ');

        extra = null;

    };

​

    lastLink =  div[div.length-1].match(/id-(.*?) /)[1];

    if( div.length < 25 || (div.length + links >= scrapeFor) ) genOutput();

    else { links += div.length; scrape( 'after=' + lastLink + '&' ); }

};

​

var genOutput = function() {

    var output = 'Easy | Intermediate | Hard | Weekly/Bonus<br />' +

                 '-----|--------------|------|-------------<br />' +

                 '| []() | []() | []() | **-** |<br />';

    Object.keys(weeks).sort((a,b) => b-a).forEach(function(week) {

        for(var diff in weeks[week]) {

            if( weeks[week][diff].length == 0 ) weeks[week][diff].push('[]()');

        }

        ['[Easy]','[Intermediate]','[Hard]','[Bonus]'].forEach(function(diff){

            output += '|' + weeks[week][diff].join();

        });

        output += '|<br />';

    });

    document.getElementsByTagName('body')[0].insertAdjacentHTML('afterbegin', output);

};

​

var scrape = function(after='') {

    var script = document.createElement('script');

    script.src = 'https://www.reddit.com/r/dailyprogrammer/new.embed?' + after + 'callback=parseLinks';

    document.getElementsByTagName('body')[0].appendChild(script);

    script.parentNode.removeChild(script);

};

​

var weeks = {};

var links = 0;

var scrapeFor = 30;

​

scrape();