var searchHTML;

  function AjaxRequest(u, cb) {
    this.callback = cb;
    this.url = u;
  }

  AjaxRequest.prototype.send = function() {
    this.request = (window.XMLHttpRequest ? new XMLHttpRequest() : (window.ActiveXObject ? new ActiveXObject("Microsoft.XMLHTTP") : null));
    var that = this;
    this.request.onreadystatechange = function() {
      that.callback(that);
    }
    this.request.open("GET", this.url, true);
    this.request.send(null);
  }


  function processSearch(req) {
    var request = req.request;
    if (request.readyState == 4) {
      if (request.status == 200) {
        var resultText = request.responseText;
        var result = eval('(' + resultText + ')');

        var x = document.getElementById(req.resultDiv);
        if (!searchHTML) {
          searchHTML = x.innerHTML.replace("<!--", "").replace("-->", "");
        }
        var baseContent = searchHTML;
        x.innerHTML = "";
        if (result.results.length == 0) {
          x.innerHTML = "Geen resultaten gevonden";
        }
        for(i=0;i<result.results.length;++i) {
          var line = baseContent;
          line = line.replace(/@TITLE@/g, result.results[i].title);
          line = line.replace(/@URL@/g, result.results[i].url);
          line = line.replace(/@ID@/g, result.results[i].id);
          line = line.replace(/@PUBLICATIONDATE@/g, DateFormatter.format(new Date(result.results[i].publicationDate), 'd/m/Y'));
          line = line.replace(/@PUBLICATIONTIME@/g, DateFormatter.format(new Date(result.results[i].publicationDate), 'H:i'));
          line = line.replace(/@SUMMARY@/g, result.results[i].summary);
          line = line.replace(/@CONTENT@/g, result.results[i].content);
          line = line.replace(/@KEYWORDS@/g, result.results[i].keywords);
          x.innerHTML = x.innerHTML + line;
        }
      } else {
        var x = document.getElementById(req.resultDiv);
        x.innerHTML = "Er is een probleem opgetreden met je zoekopdracht.";
        
      }
    }
  }


  function search(keywords, div) {
    var url;
    url = '/gbertem/servlet/search?type=simple&keywords='+keywords;
    var ajax = new AjaxRequest(url, processSearch);
    ajax.resultDiv = div;
    ajax.send();
  }

  function advancedSearch(f, div) {
    var author = f.elements['author'].value;
    var summary = f.elements['summary'].value;
    var title = f.elements['title'].value;
    var content = f.elements['content'].value;
    var fromdate = f.elements['fromdate'].value;
    var todate = f.elements['todate'].value;
    var keywords = f.elements['keywords'].value;

    if (fromdate.length != 0) {
      var d = isDate(fromdate);
      if (d == '') {
        return;
      }
      fromdate = d;
    }
    if (todate.length != 0) {
      var d = isDate(todate);
      if (d == '') {
        return;
      }
      todate = d;
    }

    var sort = f.elements['sort'];
    var sortString = '';
    for(i=0;i<sort.length;i++) {
      if (sort[i].checked) sortString = sort[i].value;
    }
    var order = f.elements['order'];
    var orderString = '';
    for(i=0;i<order.length;i++) {
      if (order[i].checked) orderString = order[i].value;
    }
    var url;
    url = '/gbertem/servlet/search?type=advanced&author='+author+'&todate='+todate+'&fromdate='+fromdate+'&content='+content+'&summary='+summary+'&title='+title+'&keywords='+keywords+'&sort='+sortString+'&order='+orderString;
    var ajax = new AjaxRequest(url, processSearch);
    ajax.resultDiv = div;
    ajax.send();
  }




var dtCh= "/";
var minYear=1900;
var maxYear=2100;

function isInteger(s){
	var i;
    for (i = 0; i < s.length; i++){   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag){
	var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++){   
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function daysInFebruary (year){
	// February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
}
function DaysArray(n) {
	for (var i = 1; i <= n; i++) {
		this[i] = 31
		if (i==4 || i==6 || i==9 || i==11) {this[i] = 30}
		if (i==2) {this[i] = 29}
   } 
   return this
}

function isDate(dtStr){
	var daysInMonth = DaysArray(12);
	var pos1=dtStr.indexOf(dtCh);
	var pos2=dtStr.indexOf(dtCh,pos1+1);
	var strDay=dtStr.substring(0,pos1);
	var strMonth=dtStr.substring(pos1+1,pos2);
	var strYear=dtStr.substring(pos2+1);
        var returnString = strYear+strMonth+strDay;
	strYr=strYear;
	if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1);
	if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1);
	for (var i = 1; i <= 3; i++) {
		if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1);
	}
	month=parseInt(strMonth);
	day=parseInt(strDay);
	year=parseInt(strYr);
	if (pos1==-1 || pos2==-1){
		alert("Het datum formaat moet dd/mm/jjjj zijn.");
		return "";
	}
	if (strMonth.length<1 || month<1 || month>12){;
		alert("Gelieve een geldige maand in te geven.");
		return "";
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		alert("Gelieve een geldige dag in te geven");
		return "";
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		alert("Gelieve een jaartal in geven tussen "+minYear+" en "+maxYear);
		return "";;
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		alert("Gelieve een geldige datum in te geven");
		return "";
	}
        return returnString;
}