// all of these functions are ripped from Typo (http://trac.typosphere.org/)
function show_dates_as_local_time() {
  var spans = document.getElementsByTagName('span');
  for (var i=0; i<spans.length; i++) {
    if (spans[i].className.match(/\btypo_date\b/i)) {
      spans[i].innerHTML = get_local_time_for_date(spans[i].title);
    }
  }
}

function get_local_time_for_date(time) {
  system_date = new Date(time);
  user_date = new Date();
  delta_minutes = Math.floor((user_date - system_date) / (60 * 1000));
  if (Math.abs(delta_minutes) <= (8*7*24*60)) { // eight weeks... I'm lazy to count days for longer than that
    distance = distance_of_time_in_words(delta_minutes);
    if (delta_minutes < 0) {
      return distance + ' from now';
    } else {
      return distance + ' ago';
    }
  } else {
    return 'on ' + system_date.toLocaleDateString();
  }
}

// a vague copy of rails' inbuilt function,
// but a bit more friendly with the hours.
function distance_of_time_in_words(minutes) {
  if (minutes.isNaN()) return "";
  minutes = Math.abs(minutes);
  if (minutes < 1) return ('less than a minute');
  if (minutes < 50) return (minutes + ' minute' + (minutes == 1 ? '' : 's'));
  if (minutes < 90) return ('about one hour');
  if (minutes < 1080) return (Math.round(minutes / 60) + ' hours');
  if (minutes < 1440) return ('one day');
  if (minutes < 2880) return ('about one day');
  else return (Math.round(minutes / 1440) + ' days');
}


function show_dates_as_system_time() {
  var spans = document.getElementsByTagName('span');
  for (var i=0; i<spans.length; i++) {
    if (spans[i].className.match(/\bsystem_date\b/i)) {
      spans[i].innerHTML = get_system_time_for_date(spans[i].title);
    }
  }

}

function get_system_time_for_date (timeString) {
  var date = new Date(timeString);
  return date.customFormat('#DDD# #MMM# #D#, #YYYY# at #h#:#mm#:#ss# #ampm#');
}

//*** This code is copyright 2002-2003 by Gavin Kistner, gavin@refinery.com
//*** It is covered under the license viewable at http://phrogz.net/JS/_ReuseLicense.txt
// See http://phrogz.net/JS/FormatDateTime_JS.txt
Date.prototype.customFormat = function(formatString){
        var YYYY,YY,MMMM,MMM,MM,M,DDDD,DDD,DD,D,hhh,hh,h,mm,m,ss,s,ampm,AMPM,dMod,th;
        var dateObject = this;
        YY = ((YYYY=dateObject.getFullYear())+"").slice(-2);
        MM = (M=dateObject.getMonth()+1)<10?('0'+M):M;
        MMM = (MMMM=["January","February","March","April","May","June","July","August",
                     "September","October","November","December"][M-1]).substring(0,3);
        DD = (D=dateObject.getDate())<10?('0'+D):D;
        DDD = (DDDD=["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"]
               [dateObject.getDay()]).substring(0,3);
        th=(D>=10&&D<=20)?'th':((dMod=D%10)==1)?'st':(dMod==2)?'nd':(dMod==3)?'rd':'th';
        formatString = formatString.replace("#YYYY#",YYYY).replace("#YY#",YY).replace("#MMMM#",
MMMM).replace("#MMM#",MMM).replace("#MM#",MM).replace("#M#",M).replace("#DDDD#",DDDD).replace("#DDD#",
DDD).replace("#DD#",DD).replace("#D#",D).replace("#th#",th);

        h=(hhh=dateObject.getHours());
        if (h==0) h=24;
        if (h>12) h-=12;
        hh = h<10?('0'+h):h;
        AMPM=(ampm=hhh<12?'am':'pm').toUpperCase();
        mm=(m=dateObject.getMinutes())<10?('0'+m):m;
        ss=(s=dateObject.getSeconds())<10?('0'+s):s;
        return formatString.replace("#hhh#",hhh).replace("#hh#",hh).replace("#h#",h).replace("#mm#",
mm).replace("#m#",m).replace("#ss#",ss).replace("#s#",s).replace("#ampm#",ampm).replace("#AMPM#",AMPM);
};