/**
  * Handle all aspects of date validation: fill error object, highlight or clear element
  * @param element elem the form element, which must have an id
  * @param object err an object where 2 properties will be filled: msg with the error message and el with elem
  * @return void
  */
function ValidateDate(elem, err) {
  if (!ValidDate(elem.value)) {
    err.msg += 'Η ημ/νία είναι λάθος\n';
    if (err.el == null) err.el = elem;
    new Effect.Highlight(elem.id, {startcolor:'#ff0000', endcolor:'#fcc8ce', duration: 0.5});
    $(elem.id).style.backgroundColor = '#fcc8ce';
  } else
    $(elem.id).style.backgroundColor = '';
}

/**
  * Checks for valid date
  * @param string dt date to check
  * @return boolean
  */
function ValidDate(dt) {
  var re = /(\d+)\/(\d+)\/(\d+)/i;
  f = dt.match(re);

  // f[0] is the initial string
  if ((!f) || (f.length != 4)) return false;
  if (f[0] != dt) return false;

      var dd = f[1];
    var mm = f[2] - 1;
    var yy = f[3];
  
  if (yy < 1900) return false;
  var r = new Date(yy, mm, dd, 0, 0, 0);
  if ((r.getFullYear() != yy) || (r.getMonth() != mm) || (r.getDate() != dd)) return false;

  return true;
}

/**
  * Checks for valid date and time
  * @param string dt datetime to check
  * @return boolean
  */
function ValidDatetime(dt) {
  var re = /(\d+)\/(\d+)\/(\d+) (\d+):(\d+)/i;
  f = dt.match(re);

  // f[0] is the initial string
  if ((!f) || (f.length != 6)) return false;
  if (f[0] != dt) return false;

      var dd = f[1];
    var mm = f[2] - 1;
    var yy = f[3];
    var hh = f[4];
  var mi = f[5];

  if (yy < 1900) return false;
  var r = new Date(yy, mm, dd, hh, mi, 0);
  if ((r.getFullYear() != yy) || (r.getMonth() != mm) || (r.getDate() != dd) ||
      (r.getHours() != hh) || (r.getMinutes() != mi)) return false;

  return true;
}
function ValidTextarea(elem) {
  return true;
}
/**
  * If valid date, returns javascript date object
  * @param string dt datetime to check in user format  (e.g. dd/mm/yyyy)
  * @return javascript date object
  */
function GetJsDate(dt) {
  if (!ValidDate(dt)) return false;

  var re = /(\d+)\/(\d+)\/(\d+)/i;
  f = dt.match(re);
      var dd = f[1];
    var mm = f[2] - 1;
    var yy = f[3];
  
  var d = new Date();
  d.setDate(dd)
  d.setMonth(mm);
  d.setFullYear(yy);

  return d;
}

/**
  * Checks for valid integer
  * @param string num number to check
  * @return boolean
  */
function ValidInt(num) {
  var length = num.length;
  var ch;

  if (length == 0) return false;

  for (var i = 0; i < length; i++) {
    ch = num.substring(i, i + 1);
    if (ch < "0" || ch > "9")
      return false;
  }
  return true;
}

/**
  * Checks for valid real (also converts , -> .)
  * @param string num_el element with number to check
  * @return boolean
  */
function ValidReal(num_el) {
  var ch;
  var decimal = 0;
  var value = num_el.value.replace(/,/, ".");
  var length = value.length;

  if (length == 0) return false;

  for (var i = 0; i < length; i++) {
    ch = value.substring(i, i + 1);
    if ((ch < "0" || ch > "9") && (ch != ".")) return false;
    if (ch == ".") { decimal++; }
    if (decimal == 2) return false;
  }
  num_el.value = value;
  return true;
}

/**
  * Checks for valid afm. Empty strings return false.
  * @param string afm to check
  * @return boolean
  */
function IsAfm(afm) {
  var a, b, c, d, e, f, g, h, i, s, y;
  var ret;

  if (afm.length != 9)
    return false;

  a = afm.charAt(0);
  b = afm.charAt(1);
  c = afm.charAt(2);
  d = afm.charAt(3);
  e = afm.charAt(4);
  f = afm.charAt(5);
  g = afm.charAt(6);
  h = afm.charAt(7);
  i = afm.charAt(8);

  s = a * 256 + b * 128 + c * 64 + d * 32 + e * 16 + f * 8 + g * 4 + h * 2;
  y = s % 11;

  ret = true;
  if ((y == 10) && (i != 0)) ret = false;
  if ((y < 10) && (i != y)) ret = false;

  return ret;
}

/**
  * Trims a string
  * @param string s the string to trim
  * @return trimmed string
  */
function trim(s) {
  while (s.substring(0, 1) == ' ')
    s = s.substring(1, s.length);
  while (s.substring(s.length - 1, s.length) == ' ')
    s = s.substring(0, s.length - 1);
  return s;
}

/**
  * Grows textarea when height is reached. To use add
  * onkeyup="GrowTextarea(this);" onfocus="GrowTextarea(this);"
  * to the <textarea>
  * @param object textarea the textarea
  * @return void
  */
function GrowTextarea(textarea) {
  var max_rows = 30;

  if (document.all) {
    // IE only. Code works on FF too, although FF doesn't come here.
    // Opera comes here, but doesn't work right (opens textarea to max_rows at once)
    var grew = false;
    while ((textarea.scrollHeight > textarea.clientHeight - 15) && (textarea.rows < max_rows)) {
      textarea.rows++;
      grew = true;
    }
    if (grew)
      textarea.scrollTop = 0;
  } else
  if ((textarea.rows) && (textarea.cols)) {
    // All others
    var i;
    var rows_num;
    var lines = textarea.value.split('\n');

    rows_num = lines.length;
    for (i = 0; i < lines.length; i++ ) {
      if (lines[i].length > textarea.cols)
        rows_num += Math.ceil(lines[i].length / textarea.cols);
    }
    textarea.rows = Math.min(max_rows, Math.max(5, rows_num));
  }
}

/**
  * Disable all buttons in the given form
  * @param object f the form
  * @return void
  */
function DisableFormButtons(f) {
  var f = document.frm;
  var el_num = f.elements.length;
  var el;

  for (var i = 0; i < el_num; i++) {
    el = f.elements[i];
    if (el.type == 'button') el.disabled = true;
  }
}

/**
  * Enable all buttons in the given form
  * @param object f the form
  * @return void
  */
function EnableFormButtons(f) {
  var f = document.frm;
  var el_num = f.elements.length;
  var el;

  for (var i = 0; i < el_num; i++) {
    el = f.elements[i];
    if (el.type == 'button') el.disabled = false;
  }
}

/**
  * Toggles a div between visible / invisible. Also changes an image (if given) to show the status.
  * @param string div_id the id of the DIV
  * @param string img_id the id of the IMG
  * @param string img_open path for image to use when open
  * @param string img_closed path for image to use when closed
  * @return void
  */
function ToggleDiv(div_id, img_id, img_open, img_closed) {
  var isVisible;
  var div = document.getElementById(div_id);
  var img = document.getElementById(img_id);

  isVisible = div.style.display == 'none' ? false : true;
  if (isVisible) {
    div.style.display = 'none';
    if (img)
      img.src = img_closed;
  } else {
    div.style.display = 'block';
    if (img)
      img.src = img_open;
  }
}

/**
  * Used by popup that displays content
  * @param string search the text to use for retrieving the article content
  * @return returns the html of an indicator gif (this is overwriten later by the actual article content)
  */
var indicator = '<center><img src="/images/indicator.gif" border="0"><\/center>';
function PopupText(search) {
  // make async call to fetch article
  var html = $.ajax({
    url: '/actions/lemma/get_article.php',
    type: 'GET',
    dataType: 'text',
    async: true,
    success: onPopupTextSuccess,
    data: 'search=' + search
  }).responseText;
  // meanwhile return the indicator
  return indicator;
}
function onPopupTextSuccess(data, textStatus) {
  // on success, replace the indicator with the actual data
  html = $('#overDiv').html();
  html = html.replace(indicator, data);
  $('#overDiv').html(html);
}


// floating Navigation Bar
function StartNavBar() {
	
  
	$(window).scroll(function () {
		
		if ( document.getElementById("navBarOK").value == "1" ) {
			if (isIE) {
				$('#navbar').css('position', 'fixed');
				$('#navbar').css('top', ($(window).height() - 80) );
			}
			//left = ($(window).width() - $('#navbar').width() - 10) / 2;
			//$('#navbar').css('left', left);
			
			if ($(window).scrollTop() > 80) {
				if ($('#navbar').is(':hidden')) {
					if (isIE) {
						$('#navbar').fadeIn();
						//$('#navbar').toggle();
					} else {
						$('#navbar').fadeIn();
						//$('#navbar').slideDown();
					}
				}
			} else {
				if ($('#navbar').is(':visible')) {
					if (isIE) {
						$('#navbar').fadeOut();
						//$('#navbar').toggle();
					} else {
						$('#navbar').fadeOut();
						//$('#navbar').slideUp();
					}
				}
			}
		}
	});

}

// polls a script periodically
function StartHeartbeat() {
  setInterval('Heartbeat();', 60 * 1000); // hit heartbeat.php every 60 seconds
}
function Heartbeat() {
  var html = $.ajax({
    url: '/includes/heartbeat.php',
    type: 'GET',
    dataType: 'text',
    async: false
  }).responseText;
}

/**
  * gathers form data from form 'form' and returns string in
  * `application/x-www-form-urlencoded' format
  */
function form_data(form) {
	var str = "AJAX=1";
	for (var i = 0 ; i < form.elements.length ; ++i)
		str += "&"+form.elements[i].name + "=" + encodeURI(form.elements[i].value);
	return str;
}

function post(uri, stuff, callback) {
	var req = window.ActiveXObject ? new ActiveXObject("Microsoft.XMLHTTP") : new XMLHttpRequest();
	if (callback != undefined) {
		req.onreadystatechange = function(timeout) {
			if ( req.readyState == 4 || timeout == "timeout" ) {
				callback((timeout != "timeout") ? req.status : -1, req.responseText);
				req = null;
			}
		}
	}
	req.open("POST", uri, ( callback != undefined ));  // username, password
	req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	req.setRequestHeader("X-Requested-With", "XMLHttpRequest");
	if (stuff == undefined) stuff = null;
	req.send( (typeof stuff == 'string' || stuff==null) ? stuff : form_data(stuff) );
	return req;
}

function notice(str) {
	document.getElementById("notice").innerHTML = str;
	$("div.notice").slideDown("slow");
}

function element(x) {
	return document.getElementById(x);
}

function SearchIndicator(id) {
  var e = $('#' + id);
  var pos = e.position();

  $('#indicator').css('top', (pos.top + e.height()) + 'px');
  $('#indicator').css('left', (pos.left + (e.width()/2) - ($('#indicator').width()/2)) + 'px');
  $('#indicator').toggle();
}

function SearchIndicatorSpecial(id) {
  var e = $('#' + id);
  var pos = e.position();

  $('#indicator').css('top', ( pos.top + 'px'));
  $('#indicator').css('left', ( pos.left - (e.width()/2) + 'px'));
  $('#indicator').toggle();
}