/*
    Smooth scrolling anchor tags
    Kenneth Kufluk 04/2k8
    Digitas
    Version 2.0
    
    TODO: only add custom event to anchors with rel footnote
    TODO: rewrite to only introduce one global variable
    TODO: jslint this code!
*/

var dtas_INTERVAL;
var dtas_STEPS = 25;
var dtas_LOADED = false;
var dtas_LOADEDTimer = 0;
var dtas_scrolled=false;

function dtas_scrollOnPageLoad() {
    // if we have a hash when we load, go straight to it.
    if (location.hash!="") dtas_scrollToHash(location.hash);
}

function dtas_stopScroll() {
    if (dtas_scrolled) return (dtas_scrolled=false);
    if (!dtas_LOADED) {
        clearTimeout(dtas_LOADEDTimer);
    }
    clearInterval(dtas_INTERVAL);
}

function dtas_updateLinks() {
    dtas_LOADED = true;
    var pageLinks = document.getElementsByTagName('a');
    for (var i=0;i<pageLinks.length;i++) {
        var lnk = pageLinks[i];
        if (!lnk.href.match(/\#$/) && (lnk.href && lnk.href.indexOf('#') != -1)) {
            var anch = lnk.href.split('#')[1];
            if ($(anch)) $(anch).name = anch;
            if (( (lnk.pathname == location.pathname) ||
                ('/'+lnk.pathname == location.pathname) ) &&
                (lnk.search == location.search)) {
                dtas_addEvent(lnk,'click',dtas_smoothScroll);
//                $(lnk).observe('click',dtas_smoothScroll);
            }
        }
    }
}
function bing() {
    alert('bing');
}

function dtas_smoothScroll(e) {
  if (window.event) {
    target = window.event.srcElement;
  } else if (e) {
    target = e.target;
  } else return;

  if (target.nodeType == 3) {
    target = target.parentNode;
  }
  if (dtas_scrollToHash(target.hash)) {
        return true;
  } else {
      // stop the actual click happening
      if (window.event) {
        window.event.cancelBubble = true;
        window.event.returnValue = false;
      }
      if (e && e.preventDefault && e.stopPropagation) {
        e.preventDefault();
        e.stopPropagation();
      }
  }
}
var hashTarget = 0;
function dtas_scrollToHash(hash) {
  // Find the <a name> tag corresponding to this href
  // First strip off the hash (first character)
   
  if(typeof(hash)=="undefined")
  {
      hash= "";
  }
  
  anchor = hash.substr(1);
//  if (anchor=="dtas_1") anchor = "dtas_top";
  // Now loop all A tags until we find one with that name
  var allLinks = document.getElementsByTagName('a');
  var destinationLink = null;
  for (var i=0;i<allLinks.length;i++) {
    var lnk = allLinks[i];
    if (lnk.name && (lnk.name == anchor)) {
      destinationLink = lnk;
      break;
    }
  }

  // If we didn't find a destination, give up and let the browser do
  // its thing
  if (!destinationLink) {
      if (anchor=="dtas_top" && document.body) {
        destinationLink = document.body;
    } else {
          return true;
    }
  }
    hashTarget = destinationLink;
  // Find the destination's position
  var destx = destinationLink.offsetLeft;
  var desty = destinationLink.offsetTop;
  var thisNode = destinationLink;
  var hiddenNodes = new Array();
  while (thisNode.parentNode &&
        (thisNode.parentNode != document.body)) {
    if (thisNode.style.display == 'none') {
        hiddenNodes[hiddenNodes.length] = thisNode;
        thisNode.style.display = '';
    }
    thisNode = thisNode.parentNode;
  }
  thisNode = destinationLink;
  while (thisNode.parentNode &&
        (thisNode.parentNode != document.body)) {
    thisNode = thisNode.parentNode;
    destx += thisNode.offsetLeft;
    desty += thisNode.offsetTop;
  }
  var lastEffect = null;
  for (var i=0;i<hiddenNodes.length;i++) {
      hiddenNodes[i].style.display = 'none';
    // custom id for ThrombosisAdviser
    if (hiddenNodes[i].id=='references') {
        effectScrollToRefs = new Effect.ScrollTo($('referenceHeader'), {queue: { position: 'end', scope: 'references'}});
        lastEffect = effectScrollToRefs;
        if (!$('referenceLink').hasClassName('on')) {
            $('referenceLink').addClassName('on');
            $('references').showNext = destinationLink;
            effectDisplayRefs = new Effect.BlindDown($('references'), {queue: { position: 'end', scope: 'references'},
                afterFinish:function() {
                      smoothScrollToAnchor($('references').showNext);
                }
            });
            lastEffect = effectDisplayRefs;
        }
    }
  }
  if (!lastEffect && destinationLink) smoothScrollToAnchor(destinationLink);
}

function smoothScrollToAnchor(destinationLink) {
    var effectScrollToAnch = new Effect.ScrollTo($(destinationLink), {queue: { position: 'end', scope: 'scroll'}});
    var effectHighlight = new Effect.Highlight($(destinationLink).parentNode, {queue: { position: 'end', scope: 'scroll'}});
}

function dtas_scrollWindow(scramount,dest,anchor) {
  wascypos = dtas_getCurrentYPos();
  isAbove = (wascypos < dest);
  dtas_scrolled=true;
  window.scrollTo(0,wascypos + scramount);
  iscypos = dtas_getCurrentYPos();
  isAboveNow = (iscypos < dest);
  if ((isAbove != isAboveNow) || (wascypos == iscypos)) {
    dtas_scrolled=true;
    window.scrollTo(0,dest);
    clearInterval(dtas_INTERVAL);
    new Effect.Highlight(hashTarget.parentNode);
  }
}

function dtas_getCurrentYPos() {
  if (document.body && document.body.scrollTop) return document.body.scrollTop;
  if (document.documentElement && document.documentElement.scrollTop)
    return document.documentElement.scrollTop;
  if (window.pageYOffset) return window.pageYOffset;
  return 0;
}

function dtas_addEvent(elm, evType, fn, useCapture) {
    // addEvent and removeEvent
    // cross-browser event handling for IE5+,  NS6 and Mozilla
    // By Scott Andrew
    if (elm.addEventListener){
        elm.addEventListener(evType, fn, useCapture);
        return true;
    } else if (elm.attachEvent){
        var r = elm.attachEvent("on"+evType, fn);
        return r;
    } else {
//        alert("Handler could not be removed");
    }
}

document.observe('dom:loaded', function() {
    dtas_scrollOnPageLoad();
    dtas_updateLinks();
});
document.observe('scroll', function() {
    dtas_stopScroll();
});