var RunForCover = function()
{
	var tracks   = [];

	// callback function for request for recent tracks feed
	processXml = function(data)
	{
	
		// loop through tracks
		jQuery('track', data).each( function()
		{
			var track = [];
			track.cdcover    = jQuery('image[size="large"]', this).text() || false;
			track.artistname = jQuery('artist', this).text();
			track.artistmbid = jQuery('artist', this).attr('mbid');
			track.name       = jQuery('name', this).text();
			track.url        = jQuery('url', this).text();
			if ('true' == jQuery(this).attr('nowplaying')) {
			track.time = 'listening now';
		} 
		else
		{
			track.time = getTimeAgo(jQuery('date', this).text(), RunForCover.settings.gmt_offset);
		}
		
		tracks.push(track);

	});
	
	display();

	};

	processArtistXml = function(data)
	{
		jQuery('artist', data).each( function()
		{
			_mbid   = jQuery('mbid', this).text();
			_name   = jQuery('name', this)[0];
			_name   = jQuery(_name).text();
			_imgurl = jQuery('image[size="large"]', this)[0];
			_imgurl = jQuery(_imgurl).text();
			
			if ('' == _imgurl)
			{
				_imgurl = 'http://cdn.last.fm/flatness/catalogue/noimage/cover_medium_new.gif';
			}
			
			// set the source of the image to the image of the artist
			
			jQuery('img[rel="' + justLetters(_name) + '"]').each( function()
			{
				jQuery(this).attr('src', _imgurl);
				jQuery(this).parent().attr('href', _imgurl);
			});
			
			// stop looping through the artists returned

			return false;

		});
	};

	justLetters = function(str)
	{
		str = str.toLowerCase();
		var _m = str.match(/[a-z]/gi);
		return _m.join ('');
	}

	display = function()
	{
		jQuery(tracks).each( function()
		{
		if (0 == RunForCover.settings.count)
		{
			return false;
		}
		if (false === this.cdcover)
		{
			// no cover image? find artist image instead
			var _newImg = jQuery('<img />').attr('src', '').attr('rel', justLetters(this.artistname)).attr('title', this.artistname + ': ' + this.name + " (" + this.time + ")");
			// and go find the image of the artist
			jQuery.get(RunForCover.settings.ajaxuri,
			{ rfc_artist: this.artistname },
			processArtistXml
			);
		} 
		else 
		{
			var _newImg = jQuery('<img />').attr('src', this.cdcover).attr('title', this.artistname + ': ' + this.name + " (" + this.time + ")");
		}

		// how to link the image?
		switch(RunForCover.settings.linkto)
		{
			/*
			case 'lightbox':
			_newImg = jQuery('<a />').attr('href', this.cdcover).attr('rel', 'lightbox').append(_newImg);
			break;
			case 'highslide':
			_newImg = jQuery('<a />').attr('href', this.cdcover).click( function() { return hs.expand(this); }).append(_newImg);
			break;
			case 'lastfm':
			default:
			_newImg = jQuery('<a />').attr('href', this.url).append(_newImg);
			break;
			*/

			case 'lightbox':
			_newImg = jQuery('<a />').attr('href', this.cdcover).attr('rel', 'lightbox').append(_newImg);
			break;
		}

		// how to style the image?
		switch(RunForCover.settings.style)
		{
			case 'imgwithtxt':
			var _table = jQuery('<div />');
			//var _tr    = jQuery('<tr />').appendTo(_table);
			// append image to new TD and append that to TR
			//_newImg.appendTo(jQuery('<td />').appendTo(_tr));
			_newImg.appendTo(jQuery('<span class="albumcover" />').appendTo(_table));
			// append second TD with track info
			var _tdR   = jQuery('<span class="songtitle"><a href="' + this.url + '">' + this.name + '</a></span><span class="artistname">' + this.artistname +  '</span><span class="playedwhen">' + this.time + '</span>').appendTo(_table);
			_newImg = _table;
			case 'justimgs':
			default:
			// nuttin'
		}

		// attach generated code to ol#runforcover
		var _newLi = jQuery('<li />').appendTo(jQuery('ol#runforcover'));

		// and add HTML to this list item
		_newImg.css('display', 'none').appendTo(_newLi).fadeIn("slow");

		RunForCover.settings.count--;

	});
	};

	getTimeAgo = function(_t, gmt_offset)
	{
		// difference between then and now
		var _diff = new Date() - new Date(_t);
		// take into account the timezone difference
		_diff = _diff - (gmt_offset * 60000 * 60);

		var _d = [];
		// how may years in the difference? not many, I hope ;-)
		_d.ye = parseInt(_diff / (1000 * 60 * 60 * 24 * 365));
		_d.da = parseInt(_diff / (1000 * 60 * 60 * 24)) - (_d.ye * 365);
		_d.ho = parseInt(_diff / (1000 * 60 * 60)) - (_d.ye * 365 * 24) - (_d.da * 24);
		_d.mi = parseInt(_diff / (1000 * 60)) - (_d.ye * 365 * 24 * 60) - (_d.da * 24 * 60) - (_d.ho * 60);

		var _meantime = [];
		if (_d.ye > 0) { _meantime.push(_d.ye + ' year' + getPluralS(_d.ye)); }
		if (_d.da > 0) { _meantime.push(_d.da + ' day' + getPluralS(_d.da)); }
		if (_d.ho > 0) { _meantime.push(_d.ho + ' hour' + getPluralS(_d.ho)); }
		if (_d.mi > 0) { _meantime.push(_d.mi + ' minute' + getPluralS(_d.mi)) };

		// TODO: replace last comma with 'and'
		return _meantime.join(', ') + ' ago';
	}

	getPluralS = function(_c)
	{
		return (1 == _c) ? '' : 's';
	}

	// public
	return{
	settings: [],


	// to start running for covers
	start: function() {
	  // get recent tracks feed from last.fm
	  jQuery.get(this.settings.ajaxuri, { rfc_user: this.settings.username, rfc_count: this.settings.count }, processXml);
	}
};
}();