// --------------------------------------
// Index page
// --------------------------------------

var scrollY = 0;
var distance = 1;
var speed = 35;

// Scroll entire page for presentation purposes
function autoScrollTo(el){
  var currentY = window.pageYOffset;
  var targetY = document.getElementById(el).offsetTop;
  var bodyHeight = document.body.offsetHeight;
  var yPos = currentY + window.innerHeight;
  var animator = setTimeout('autoScrollTo(\'' +el+'\')', speed);
  document.onkeypress = function (e) {
    var  e = e || window.event;
    var keyunicode = e.charCode || e.KeyCode
    if(keyunicode == 98) {	
      clearTimeout(animator);
    }
    if(keyunicode == 115) {
      animator = setTimeout('autoScrollTo(\''+el+'\')', speed);
    } 	
    if(keyunicode == 114) {
      resetScroller('container');}	
  };
  
  if(yPos > bodyHeight) {
    clearTimeout(animator);}
  else {
    if(currentY < targetY-distance) {
      scrollY = currentY+distance;
      window.scroll(0,scrollY);
    } else {
      clearTimeout(animator);}
  }		
}

var new_scrollY = 0;

function resetScroller(el) {
  var currentY = window.pageYOffset;
  var targetY = document.getElementById(el).offsetTop;
  var animator = setTimeout('resetScroller(\''+el+'\')', speed);
  if(currentY > targetY) {
    new_scrollY = currentY - distance;
    window.scroll(0,new_scrollY);
  } else {
    clearTimeout(animator);
  }	
}	

document.onkeypress = function (e) {
  var  e = e || window.event;
  var keyunicode2 = e.charCode || e.KeyCode
  if(keyunicode2 == 115) {
    autoScrollTo('end');	
  }

};

// --------------------------------------
// Turing Machine page
// --------------------------------------

// Function used to simulate turing machine computation.
function Start() {
  var delay = 1000;
  
  setTimeout(function(){document.getElementById("p1").style.visibility = 'hidden';}, delay);

  setTimeout(function(){document.getElementById("p2").style.visibility = 'visible';}, delay);				
  
  setTimeout(function(){
    document.getElementById("p2").style.visibility = 'hidden'
    document.getElementById("p3").style.visibility = 'visible';}, delay + 2000);
  
  setTimeout(function(){
    document.getElementById("p3").style.visibility = 'hidden'
    document.getElementById("p4").style.visibility = 'visible';}, delay + 3000 );
  
  setTimeout(function(){
    document.getElementById("d1").innerHTML = "1";}, delay + 4500);
  
  setTimeout(function(){
    document.getElementById("p4").style.visibility = 'hidden'
    document.getElementById("p5").style.visibility = 'visible';}, delay + 6000);	
  
  setTimeout(function(){
    document.getElementById("p5").style.visibility = 'hidden'
    document.getElementById("p6").style.visibility = 'visible';}, delay +7000);
  
  setTimeout(function(){
    document.getElementById("p6").style.visibility = 'hidden'
    document.getElementById("p7").style.visibility = 'visible'
    document.getElementById("d3").style.border = '1px solid black'
    document.getElementById("d3").style.visibility = 'visible';}, delay + 8500 );
  
  setTimeout(function(){
    document.getElementById("p7").style.visibility = 'hidden'
    document.getElementById("p6").style.visibility = 'visible'
    document.getElementById("d3").style.visibility = 'hidden';}, delay + 10000);	
  
  setTimeout(function(){
    document.getElementById("d2").innerHTML = "0";}, delay + 11000);	
}

// resets state of tape after computation is done
function rst() {
  document.getElementById("p1").style.visibility = 'visible';
  document.getElementById("p2").style.visibility = 'hidden';
  document.getElementById("p3").style.visibility = 'hidden';
  document.getElementById("p4").style.visibility = 'hidden';
  document.getElementById("d1").innerHTML = "+";
  document.getElementById("p5").style.visibility = 'hidden';
  document.getElementById("p6").style.visibility = 'hidden';	
  document.getElementById("p7").style.visibility = 'hidden';
  document.getElementById("d2").innerHTML = "1";
  document.getElementById("d3").style.visibility = "hidden";
}

// --------------------------------------
// Bletchley Park page
// --------------------------------------
var element;
var title;
var string1;
var string2;

function randomString(length, chars) {
  var result = "";
  result = chars[Math.round(Math.random() * (chars.length - 1))];
  return result;
}
	
function changeText(id1, id2, text1, text2) {
  document.getElementById(id2).textContent = text2;
  document.getElementById(id1).textContent = text1;
}

// returns i-th character of final string to be displayed
function goodString(i) {
  var name =  "Bletchley Park";
  var title = "Alan Turing   ";
  return [name[i], title[i]];
}

// upon startup of page load random text instead of proper title
function loadCipherText() {
  for(var i = 1; i < 15; i++) {
    string1 = randomString(1, "ABCDEFGHIJKLMNOPQRSTUVWXYZ");
    string2 = randomString(1, "ABCDEFGHIJKLMNOPQRSTUVWXYZ");			
    element = "word" + i;
    title = "title" + i;
    changeText(element, title, string1, string2);
  }
}

var newmaxLoops = 15;
var newcounter = 0;
var newelement;
var newtitle;
var newstring1;
var newstring2;
var newi = 14;

setTimeout(function() {
  (function newText() {
    if( newcounter++ >= newmaxLoops) return;
    setTimeout(function(){
      newstring1 = randomString(1,"ABCDEFGHIJKLMNOPQRSTUVWXYZ");
      newstring2 = randomString(1,"ABCDEFGHIJKLMNOPQRSTUVWXYZ");
      newelement = "word" + newi;
      newtitle = "title" + newi;
      changeText(newelement, newtitle, newstring1, newstring2);
      newi--;
      newText();
    }, 150);
  })();}, 300);

var finalmaxLoops = 15;
var finalcounter = 0;
var finalelement;
var finaltitle;
var finalstring1;
var finalstring2;
var finali = 1;
var finale = 0;

setTimeout(function() {
  (function finalText() {
    if( finalcounter++ >= finalmaxLoops) return;
    setTimeout(function(){
      var texts = goodString(finale);
      finalstring1 = texts[0];
      finalstring2 = texts[1];
      finalelement = "word" + finali;
      finaltitle = "title" + finali;
      changeText(finalelement,finaltitle,finalstring1,finalstring2);
      finali++;
      finale++;
      finalText();
    }, 200);
  })();}, 2700);	


// --------------------------------------
// Enigma page
// --------------------------------------

var images = 1;
var totimages = 2;
var text1 = "3 rotori da inserire in Enigma";
var text2 = "Struttura interna del rotore";

function slide_enigma(x) {
  var Image = document.getElementById('rotors');
  images += x;
  if (images > totimages){
    images = 1;}
  else if(images == 0) {
    images = totimages;}
  if(images == 1) {var text = text1;}
  if(images == 2) {var text = text2;} 
  Image.src= "../media/images/enigma/rotor" + images + ".jpg";
  document.getElementById('rotori_text').textContent = text;
  
}
	
var text1 = "3 rotori da inserire in Enigma";
var text2 = "Struttura interna del rotore";

window.setInterval(function slide_enigmaA() {
  var Image = document.getElementById('rotors');
  images += 1;
  if (images > totimages){
    images = 1;
  }
  else if(images == 0) {
    images = totimages;
  }
  if(images == 1) {var text = text1;}
  if(images == 2) {var text = text2;} 		
  Image.src= "../media/images/enigma/rotor" + images + ".jpg"; 
  document.getElementById('rotori_text').textContent = text;
},15000);