// ---------------- variables --------------------------------------------------
var clock_host = 'http://clock.time.in.ua/';
var clock_html = 'clock.html';
var offsetCookie = 'to';
var req, reqstart, reqend, response, offset;
var time_width,time_height,time_border,time_bg,w,h,undef;

// ---------------- SNTP via HTTP syncronization -------------------------------

function loadXMLDoc(url) {
  // branch for native XMLHttpRequest object
  if (window.XMLHttpRequest) {
    req = new XMLHttpRequest();
    req.onreadystatechange = processReqChange;
    req.open("GET", url, true);
    req.setRequestHeader('Pragma', 'no-cache');
    req.setRequestHeader('Cache-control', 'no-cache');
    req.send(null);
  }
  else if (window.ActiveXObject) {
    // branch for IE/Windows ActiveX version
    req = new ActiveXObject("Microsoft.XMLHTTP");
    if (req) {
      req.onreadystatechange = processReqChange;
      req.open("GET", url, true);
      req.setRequestHeader('Pragma', 'no-cache');
      req.setRequestHeader('Cache-control', 'no-cache');
      req.send();
    }
  }
}

function processReqChange()
{
  // only if req shows "complete"
  if (req.readyState == 4) {
    // only if "OK"
    if (req.status == 200 || req.responseText != undef) {
      // ...processing statements go here...
      response = req.responseText;
      reqend = (new Date()).getTime();
      offset = (reqend-reqstart)/2;
      // real time (in microseconds) is response * 1000 + offset
      // user's time (in microseconds) is reqend
      // difference is reqend - (response * 1000 + offset)
      offset = reqend - response*1000 - offset;
      var expire = new Date();
      expire.setTime(expire.getTime() + 300 * 1000); // 1 hour
      if (Math.abs(offset) < 1e4) setCookie(offsetCookie, offset, expire.toGMTString());
      display();
    }
    else {
      alert("There was a problem retrieving the XML data:\n" + req.statusText);
    }
  }
}

function display() {
  var timer = (new Date()).getTime();
  var real = timer + offset;
  real = Math.round(real);
  real = real.toString();
  real = 1000-real.substr(real.length-3);
  setTimeout("displayTime()", real);
  var im = document.getElementById("img");
  if (im) {
    if (Math.abs(offset) > 1000) im.src = "http://clock.time.in.ua/images/clock-no.png";
    else im.src = "http://clock.time.in.ua/images/clock-ok.png";
    im.title = "Your system clock is "+(offset >= 0 ? 'faster' : 'slower')+" in "+Math.abs(offset)+" ms";
  }
}

function startSync() {
  offset = parseInt(getCookie(offsetCookie));
  if (offset) {
    display(offset);
  }
  else {
    url = clock_host + "?r=" + Math.random();
    loadXMLDoc(url);
  }
}

function displayTime() {
  var div = document.getElementById("time");
  var time = new Date();
  time.setTime(time.getTime() - offset);
  div.innerHTML = d2(time.getHours())+":"+d2(time.getMinutes())+":"+d2(time.getSeconds());
  setTimeout("displayTime()", 1000);
}

function d2(val) {
  if (val < 10) val = "0"+val;
  return val;
}

function setCookie (name, value, expires, path, domain, secure) {
  document.cookie = name + "=" + escape(value) +
          ((expires) ? "; expires=" + expires : "") +
          ((path) ? "; path=" + path : "") +
          ((domain) ? "; domain=" + domain : "") +
          ((secure) ? "; secure" : "");
}

function getCookie(name) {
  var cookie = " " + document.cookie;
  var search = " " + name + "=";
  var setStr = null;
  var offset = 0;
  var end = 0;
  if (cookie.length > 0) {
    offset = cookie.indexOf(search);
    if (offset != -1) {
      offset += search.length;
      end = cookie.indexOf(";", offset);
      if (end == -1) end = cookie.length;
      setStr = unescape(cookie.substring(offset, end));
    }
  }
  return(setStr);
}


// ---------------- CSS definition --------------------------------------------
function css() {
  try {
    if (time_width == undef || time_height == undef || time_width == 0 || time_height == 0) {
      time_width = undef;
      time_height = undef;
    }
    if (time_width == undef) time_width = 88;
    if (time_height == undef) time_height = 31;
    var w=time_width,h=time_height;
    if (time_border == undef) time_border = 'black 1px solid';
    if (time_border == '') time_border = '0px none';
    if (match = time_border.match(/\b([0-9]+)px\b/)) {
      w -= match[1]*2;
      h -= match[1]*2;
    }
    if (time_bg == undef) time_bg = 'http://clock.time.in.ua/images/clock-bg-'+time_width+'-'+time_height+'-1.gif';
    var obj = document.getElementById("timeinua");
    if (obj) {
      if (obj.style) {
        obj.style.margin = '0px';
        obj.style.padding = '0px';
        obj.style.fontSize = '1px';
        obj.style.width = w+'px';
        obj.style.height = h+'px';
        obj.style.border = time_border;
        obj.style.overflow = 'hidden';
        obj.style.whiteSpace = 'nowrap';
        if (time_bg) {
          if (time_bg.indexOf('#') == 0) obj.style.backgroundColor = time_bg;
          else if (time_bg.indexOf('http://') == 0) obj.style.background = "url('"+time_bg+"')";
        }
      }
      var obj1 = obj.getElementsByTagName('div');
      for(var i=0; i<obj1.length; i++) {
        if (obj1[i].style) {
          obj1[i].style.font = '8pt Verdana,Tahoma';
          obj1[i].style.textAlign = 'center';
          if (i == 0) {
            obj1[i].style.lineHeight = '0.9';
            obj1[i].style.height = '10px';
            obj1[i].style.overflow = 'hidden';
          }
        }
      }
      obj1 = obj.getElementsByTagName('a');
      if (obj1.length && obj1[0] && obj1[0].href.indexOf('http://time.in.ua/') == 0) {
        obj1[0].style.color = '#0000a0';
        obj1[0].style.textDecoration = 'none';
      }
      else {
        clock_html += '?error';
      }
    }
    else {
      clock_html += '?error';
    }
  }
  catch(e) { }
}

// ---------------- main programm start --------------------------------------
if (window.location.href.indexOf(clock_host) == 0) {
  if (window.location.href.indexOf('error') == -1) {
    reqstart = (new Date()).getTime();
    startSync();
  }
  else {
    var obj = document.getElementById("img");
    if (obj) {
      obj.style.visibility = 'hidden';
      obj.style.width = '0px';
    }
    obj = document.getElementById("time");
    obj.innerHTML = 'code error';
  }
}
else {
  css();
  document.write('<iframe src="'+clock_host+clock_html+'" frameborder="0" marginwidth="0" marginheight="0" vspace="0" hspace="0" width="'+w+'" height="18" scrooling="no" allowtransparency="true"></iframe>');
}