/**
  * 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){
   //try adding zero seconds in end of string and test again
   if( (f[0] + ':00') != dt){ 
     return false;  //if still differs return
   }  
 }  

      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;
}

/**
  * 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.setMinutes(15, 0, 0);
  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 textarea
  * @param string
  * @return boolean
  */
function ValidTextarea(text) {
  return true;
}

/**
  * 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));
  }
}

/**
  * Check if field is empty, focus and alert
  */
function HasMinChars(fld, min_chars) {
  if (min_chars === undefined)
    min_chars = 1;

  if (fld.value.length< min_chars) {
    var s = 'Υποχρεωτικό πεδίο';
    if (min_chars > 1)
      s += '. Δώστε τουλάχιστον ' + min_chars + ' χαρακτήρες';
    ShowError(fld, s);
    return false;
  }

  HideError(fld);
  return true;
}

/**
  * Display an error for a field
  */
function ShowError(fld, msg) {
  alert(msg);
  fld.focus();
  fld.style.borderColor = '#ff0000';
}

/**
  * Hide an error
  */
function HideError(fld) {
  fld.style.borderColor = '';
}

// Requires jquery. Submit datagrid filter form on pressing enter
$(function() {
  var FilterBox = $('div.datagrid_filters_body input,div.datagrid_filters_body select');
  var code =null;
  FilterBox.keypress(function(e){
    code = (e.keyCode ? e.keyCode : e.which);
    if (code == 13)
      $('form[name=' + this.form.name + '] div.datagrid_filters_body input:button:first').click();
  });
});