// ==UserScript==
// @name           Outputz bar chart
// @namespace      http://d.hatena.ne.jp/youz/
// @include        http://outputz.com/*
// ==/UserScript==

(function(){
   var make_uri = function (param) {
     var q = '';
     for (k in param) { q += '&' + k + '=' + param[k]; }
     return 'http://chart.apis.google.com/chart?' + q;
   };

   var parse_uri = function (uri) {
     var params = {};
     uri.split(/[?&]/g).slice(1).forEach(
       function(s){
         var p = s.split(/=/);
         params[p[0]] = p[1];
       });
     return params;
   };

   var imgs=document.images;
   for (var i=0; i<imgs.length; ++i) {
     if (imgs[i].src.match(/cht=p3/)) {
       var p = parse_uri(imgs[i].src);
       var d = p['chd'].substr(2).split(',').map(parseFloat);
       var dmax = Math.ceil(Math.max.apply(null, d)/10)*10;
       var params = {
         'chs': '500x420',
         'chbh': (320/d.length).toFixed(),
         'cht': 'bhs',
         'chco': p['chco'] || '4d89f9',
         'chd': 't:' + d.reverse().join(','),
         'chds': '0,' + dmax,
         'chg': '10,0',
         'chxt': 'x,y',
         'chxl': ['0:', [0,1,2,3,4,5].map(function(i){ return dmax*i/5; }).join('|'),
                  '1:', p['chl']
                 ].join('|')
       };
       imgs[i].src = make_uri(params);
     }
   };
})();