var FIRST_DEPARTURE_DAY = 4;
  var LAST_DEPARTURE_DAY = 365;
  var YAHOO_CAL_DATE_PATTERN = "m/d/Y";
  
  var processCalEvents = true;
  //var myLogReader;
  var calHovering = true;
  
  YAHOO.namespace("mp.calendar");

  //
  // Writes selected date string from calendar int correct text field component.
  //
  function setDateFromCalendar(calId, value) {
  
    var textField = document.getElementById(calId == 'calDep' 
      ? 'departureDate' : 'returnDate');
      
    textField.value = value;
    
    
  }
  
  
  //
  //
  //
  //
  var setupMouseListeners = function(eventType, args, cal) {  
  
    //YAHOO.log("registering listeners for " + cal.id);
  
    YAHOO.util.Event.addListener(cal.id, "mouseover", calMouseOver);
    YAHOO.util.Event.addListener(cal.id, "mouseout", calMouseOut);
      
  }
  
  
  //
  // Configures calendars initial properties. 
  //
  function configureCalendar(cal) {
  
    var firstDepartureDate = new Date();
    firstDepartureDate.setDate(firstDepartureDate.getDate() + FIRST_DEPARTURE_DAY);
      
    cal.cfg.setProperty("pages", 3);
    cal.cfg.setProperty("mindate", firstDepartureDate.dateFormat('m/d/Y'));
    cal.cfg.setProperty("pagedate", firstDepartureDate.dateFormat('m/Y'))
    cal.cfg.setProperty("close", true);    
    cal.cfg.setProperty("MONTHS_LONG", ["Tammikuu", "Helmikuu", "Maaliskuu", "Huhtikuu", "Toukokuu", "Kesäkuu", "Heinäkuu", "Elokuu", "Syyskuu", "Lokakuu", "Marraskuu", "Joulukuu"]);
    cal.cfg.setProperty("WEEKDAYS_SHORT", ["Su","Ma","Ti","Ke","To","Pe","La"]);
    cal.cfg.setProperty("START_WEEKDAY", 1);    
        
    if (cal.id == 'calDep') {
      cal.cfg.setProperty("title", "Lähtöpäivä:");       
    } else {
      cal.cfg.setProperty("title", "Paluupäivä:");           
    }
    
    
  }
  
  
  //
  // Handles calendar mouse out event to mark that user is not selecting dates
  // anymore and we can close the calendar at will.
  //
  function calMouseOut() {
  
    //YAHOO.log("MouseOut");
    calHovering = false;
  
  }
  
  
  //
  // Handles calendar mouse over event to mark that user is selecting dates
  // and thus we should not close the calendar before selection is made.
  //
  function calMouseOver() {
  
    //YAHOO.log("MouseOver");
    calHovering = true;
  
  }
  
  
  //
  // Returns the user entered (or selected) departure date from departure date
  // text field or null if not valid.
  //
  // todo: some masking be nice
  //
  function getDepartureDateAsDate() {
  
    return getStringAsDate(document.getElementById('departureDate').value);
    
  }
  
  
  //
  // Tries to convert given string into a date object. If conversion fails,
  // null is returned.
  // 
  // todo: take pattern from selected locale.
  //
  function getStringAsDate(str) {
    
    return Date.parseDate(str, 'd.m.Y');  
  
  }
  
  
  //
  // Callback handler for hiding opened calendar.
  //
  var hideCalendar = function(eventType, cal) {
  
    if (!calHovering) {
      cal.hide();
    }
    
  }
  
  
  //
  // Sets the selection boundaries on given calendar
  //
  function setCalendarDateRange(cal, minDate, maxDate) {
  
    if (minDate == null) {
      minDate = new Date();
    }
    
    if (maxDate == null) {
      maxDate = new Date();
      maxDate.setDate(minDate.getDate() + LAST_DEPARTURE_DAY);
    }
    
    cal.cfg.setProperty("mindate", minDate.dateFormat(YAHOO_CAL_DATE_PATTERN)); 
    cal.cfg.setProperty("maxdate", maxDate.dateFormat(YAHOO_CAL_DATE_PATTERN));
  
  }
  
  
  //
  // Callback handler for showing the calendar with selected value.
  //
  var showCalendar = function(eventType, cal) {
  
    //YAHOO.log("showCalendar");
  
    var textField = document.getElementById(cal.id == 'calDep' 
      ? 'departureDate' : 'returnDate');
    
    var date = Date.parseDate(textField.value, 'd.m.Y');
    
    if (date != null) {
   
      var dateStr = date.dateFormat(YAHOO_CAL_DATE_PATTERN);
      //alert("value to parse " + textField.value
      //  + ", parsed to " + date
      //  + ", formatted to " + dateStr);

      processCalEvents = false;
      cal.select(date.dateFormat(dateStr));
      processCalEvents = true;
					
      var firstDate = cal.getSelectedDates()[0];
      cal.cfg.setProperty("pagedate", (firstDate.getMonth()+1) + "/" + firstDate.getFullYear());
        
    }
    
    //
    // Make sure we're not returning before we depart.
    //
    if (cal.id == 'calRet') {
    
      var departureDate = getDepartureDateAsDate();
      setCalendarDateRange(cal, departureDate, null);
    
    }
    
    
    cal.render();    
    cal.show();
    
  }
  
  
  //
  // Callback handler for updating text field with calendars selection.
  //
  var onDateSelectHandler = function(type, args, obj) {
  
    //YAHOO.log("Date selected type: " + type + ", args: " + args + ", obj: " + obj);
  
  
    if (!processCalEvents) {
      return;
    }
      
    var dates = args[0]; 
    var date = dates[0]; 
    var year = date[0];
    var month = date[1];
    var day = date[2]; 
    
    setDateFromCalendar(obj.id, day + "." + month + "." + year);
    
    calHovering = false;
    obj.hide();
        
  }
  
  
  function initDefaultDates() {
  
    var firstDepartureDate = new Date();
    firstDepartureDate.setDate(firstDepartureDate.getDate() + FIRST_DEPARTURE_DAY);
      
    var departureText = document.getElementById('departureDate');
    var returnText = document.getElementById('returnDate');
    
    departureText.value = firstDepartureDate.dateFormat('d.m.Y');
    
    firstDepartureDate.setDate(firstDepartureDate.getDate() + 7);
    returnText.value = firstDepartureDate.dateFormat('d.m.Y');   
    
  }
  
  
  function initDefaultAirports() {
  
    var departureField = document.getElementById("departureText");
    if (departureField.value == '') {
      departureField.value = 'Helsinki, HEL';
    }
  
  }
  
  
  function init() {
      
      initDefaultAirports();
      
      //
      // This needs from come from the session or request otherwise we'll always
      // overwrite existing values.
      //
      //initDefaultDates();
  
      YAHOO.mp.calendar.calDep = new YAHOO.widget.Calendar("calDep","calDepContainer");
      YAHOO.mp.calendar.calRet = new YAHOO.widget.Calendar("calRet","calRetContainer");
      
      configureCalendar(YAHOO.mp.calendar.calDep);
      configureCalendar(YAHOO.mp.calendar.calRet);
      
      YAHOO.mp.calendar.calDep.render();
      YAHOO.mp.calendar.calRet.render();
      
      YAHOO.util.Event.addListener("departureDate", "focus", showCalendar, YAHOO.mp.calendar.calDep, true);      
      YAHOO.util.Event.addListener("returnDate", "focus", showCalendar, YAHOO.mp.calendar.calRet, true);
      
      YAHOO.util.Event.addListener("departureDate", "blur", hideCalendar, YAHOO.mp.calendar.calDep, true);
      YAHOO.util.Event.addListener("returnDate", "blur", hideCalendar, YAHOO.mp.calendar.calRet, true);
      
      YAHOO.mp.calendar.calDep.renderEvent.subscribe(setupMouseListeners, YAHOO.mp.calendar.calDep, true); 
      YAHOO.mp.calendar.calRet.renderEvent.subscribe(setupMouseListeners, YAHOO.mp.calendar.calRet, true);     
      
      YAHOO.mp.calendar.calRet.selectEvent.subscribe(onDateSelectHandler, YAHOO.mp.calendar.calRet, true); 
      YAHOO.mp.calendar.calDep.selectEvent.subscribe(onDateSelectHandler, YAHOO.mp.calendar.calDep, true);    
      
      //myLogReader = new YAHOO.widget.LogReader(); 
      //myLogReader.show();
      
  }
  
  
  YAHOO.util.Event.addListener(window, "load", init);