/********************************* About *******************************
 * This script governed by the GNU Lesser General Public License
 * by Nathaniel Fitzgerald-Hood Central Queensland University
 * based on JavaScript WebVoyage(TM) Timer v2.0
 * by Jim Robinson, http://library.tccd.edu/code/
 *
 * The timer.js script requires the following files: timer.css
 ***********************************************************************/

function SessionTimer( sessionTime, displayType ) {
  // the number of seconds until timeout
  this.sessionIdleTime = sessionTime;
  // remaining number of seconds when the popup window appears
  this.remindTime = 55;
  // the relative URI of the login page / page to request in order to reset session timer
  this.loginUrl = "loginPage.do";
  this.sessionRefreshRequest = "signin.do";
  // warning text
  this.warningText = "Your session will end soon.<br />To keep your work, click Continue Session<br />To ignore click Cancel";
  this.alertWarningText = "Your session will end soon.\nTo keep your work, click 'OK' to continue \nor to ignore click 'Cancel'";
  // timed-out text
  this.timeoutText = "Your session has ended.<br />You will need to login again to continue.";
  this.status = "IN_SESSION"; //IN_SESSION, WARN, EXPIRED

  this.displayType = displayType; //one of: ALERT, DIALOG
  this.secondsRemaining = 0;
  this.seconds = 0;
  this.ignoreWarning = false;
  this.msgBox;
  this.timeoutID;
  this.interval = 1; // 1 second intervals
}

SessionTimer.prototype.init = function( ) {
  //insert popup into document
  if (this.displayType == "DIALOG") {
  if (!document.getElementById) return false;
    msgBox = document.createElement("div");
    msgBox.id = "warningDiv";
    msgBox.innerHTML = this.getWarning();
    body = document.getElementsByTagName("body")[0];
    body.insertBefore( msgBox, body.firstChild);
    this.msgBox = msgBox;
  }
  this.reset();
  this.tick();
}

SessionTimer.prototype.reset = function() {
  //set seconds, (re)init warning boxes
  this.secondsRemaining = this.sessionIdleTime;
  this.status = 'IN_SESSION';
}

SessionTimer.prototype.tick = function() {
	fmtMinutes = Math.floor(this.secondsRemaining/60);
	seconds = this.secondsRemaining%60;
	if(seconds < 10) {
		seconds = "0" + seconds; // format seconds for display
	}
	if (this.secondsRemaining < 0) {
		timeRemainingMsg = this.formatTime("Session has timed out");
		//if(this.displayType == "ALERT" || (this.displayType == "DIALOG" && !this.ignoreWarning)) {
			this.setExpiredDialog();
      this.showDialog();
      this.status = 'EXPIRED'
		//}
	} else if(this.secondsRemaining > 0 && this.secondsRemaining <= this.remindTime) {
		if (!this.ignoreWarning) {
      this.setWarningDialog();
      this.showDialog();
    }
		timeRemainingMsg = this.formatTime("Session timeout in: " + fmtMinutes + " minutes, " + seconds + " seconds");
	} else {
		timeRemainingMsg = this.formatTime("Session timeout in: " + fmtMinutes + " minutes, " + seconds + " seconds");
	}
	if (this.secondsRemaining >= -1 && !this.ignoreWarning) {
	  this.timeoutId = setTimeout("timer.tick()", 1000*this.interval); // restart the timer for another second
  }
  if (this.displayType =="DIALOG" && this.msgBox.style.display == "block") {
    document.getElementById("timeRemaining").value = timeRemainingMsg;
  }
	this.secondsRemaining -= this.interval;
  //alert( this.secondsRemaining
}

SessionTimer.prototype.formatTime = function(x) {  // Format the time
	var pattern = new RegExp("&#([0-9]+);");
	while ((result = pattern.exec(x)) != null) {
		x = x.replace(result[0], String.fromCharCode(RegExp.$1));
	}
	x = x.replace(/&nbsp;/g, ' ');
	return x;
}

SessionTimer.prototype.showDialog = function() {
  if (this.displayType == "DIALOG") {
    if (this.msgBox.style.display != "block") {
      this.msgBox.style.display = "block";
    }
  } else {
    if (this.status == "WARN") {
      result = confirm(this.alertWarningText);
      if (result) { //OK
        this.refreshPage();
      } else { //cancel
        this.cancelWarning();
      }
    } else if (this.status == "EXPIRED") {
      confirm( this.timeoutText );
      this.login();
    }
  }
}

SessionTimer.prototype.hideDialog = function() {
  if (this.displayType == "DIALOG" && this.msgBox.style.display == "block") {
    this.msgBox.style.display = "none";
  }
}

SessionTimer.prototype.setMessage = function( message ) {
  if (this.displayType == "DIALOG") {
    document.getElementById("warningHeader").innerHTML = message;
  }
}
SessionTimer.prototype.setButtons = function( buttons ) {
  if (this.displayType == "DIALOG") {
    document.getElementById("actionButtons").innerHTML = buttons;
  }
}

SessionTimer.prototype.setWarningDialog = function() {
  if (this.status != "WARN") {
    this.setMessage( this.warningText );
    button1 = '<input type="button" name="refresh" id="refresh" value="Continue Session" onclick="timer.refreshPage()">';
    button2 = '<input type="button" name="restart" id="cancel" value="Cancel" onclick="timer.cancelWarning()">';
    this.setButtons( button1 + button2 );
    this.status = "WARN";
  }
}

SessionTimer.prototype.setExpiredDialog = function() {
  if (this.status != "EXPIRED") {
    this.setMessage( this.timeoutText );
    button1 = '<input type="button" name="refresh" id="refresh" value="OK" onclick="timer.login()">';
    this.setButtons( button1 );
    this.status = "EXPIRED";
  }
}

/**** actions.. should eventually be converted to events ****/

// loads an image which restarts the session clock and the timer
// Hides the warning
SessionTimer.prototype.refreshPage = function() {
  //load an uncached image and close box
  var oImage = new Image;
  oImage.src = this.sessionRefreshRequest + "?" + Math.random(); // need <- better random #
  this.hideDialog();
  window.status = "Session refreshed";
  this.reset();
  //what's happening to ticks?
}

SessionTimer.prototype.login = function() {
  if (parent.frames.length != 0) {
    // loaded in frames
    top.location = this.loginUrl;
  }
  else {
    // not loaded frames
    window.location.href = this.loginUrl;
  }
}

SessionTimer.prototype.cancelWarning = function() {
  this.ignoreWarning = true;
  this.hideDialog();
}

SessionTimer.prototype.getWarning = function() {
	var myDiv  = '<div id="warningAlert">Application alert</div><form name="warningForm">';
	myDiv += '<p id="warningHeader"> </p><p class="timer">';
	myDiv += '<input type="text" name="timeRemaining" id="timeRemaining" size="50" readonly=true" />';
	myDiv += '</p><p id="actionButtons">';
	myDiv += '</p></form>';
	return myDiv;
}