// war5.js.txt - use with sink.html, fire.html or space.html
// All code and interface design are copyright Mike Capstick
// 170625 - rewrite of loadquestions and assess to display correct answer
// 250717 - set no. of ships
// 110717 - bug fixed on restart images not clearing
// 210317 - added doafterclose for pulser
// 070117 - randomise question locations
// 211216 - Places ojects at random locations in grid
// 171216 - increase flexibility to allow non war themes and images
// 210611 added sounds
// 300511 1. allows questions to contain a mixture of 4 or 5 distractors
//        2. simplified html files by moving code into this file
//        3. number of questions now unrestricted
//        4. test for empty tails to allow for other question banks to be used 

// 210411 - added support for quiz title
   if(typeof title!='string'){title=''} //  use quiz title if available
   
   maxterms=questions.length-1;  // how many questions in bank
   distractornum=0; // allows 4 or 5 distractors in a question

   //initialise parts of a question as a set of arrays
   stemarray=new Array();
   answer=new Array();
   adistract=new Array();
   bdistract=new Array();
   cdistract=new Array();
   ddistract=new Array();
   edistract=new Array();  //added to allow 5 distractors
   tail=new Array();
   var thisquestion=0;

//populate the questions arrays
for (i=0;i<maxterms;i++)
     { thisquestion=i+1;
       testsplit=questions[thisquestion].split('~');

        if ((testsplit[5]=='A')||(testsplit[5]=='B')||
            (testsplit[5]=='C')||(testsplit[5]=='D'))
             {distractornum=4;}  //  only 4 distractors, hide 5th
        else {distractornum=5;}

        shakeup(); // function to shuffle the answers

        stemarray[i]=testsplit[0];
        adistract[i]=testsplit[1];
        bdistract[i]=testsplit[2];
        cdistract[i]=testsplit[3];
        ddistract[i]=testsplit[4];
        if (distractornum==5)
           {edistract[i]=testsplit[5];
            answer[i]=testsplit[6];
            tail[i]=testsplit[7];
           }
        else {answer[i]=testsplit[5];
              tail[i]=testsplit[6];
             }
      }

// global variables
var response='0';       // set response to wrong
var hits=0;             // used to count hits
var questions=0;        // number of questions in this quiz (review)
numbers = new Array(); // 060117 - declare an array for unique numbers
ammo=maxterms;
numships=7;

// preload explosion
 soundfiles=['start.mp3','correct1.mp3','wrong1.mp3','explode.mp3'];


 for (i=0;i<soundfiles.length;i++)  //preload sound files
     {soundfiles[i]= new Object();}
     
function startup(){
    soundplayer('start');
    
    // hide play again box and button
     document.getElementById('resetbox').style.display='none';
     document.getElementById('resetbutton').style.display='none';
     
    uniques(); // setup uniques for random location of questions
    loadquestions(); // load questions
    
    document.getElementById('title').innerHTML=title+' '+aboxtitle;
   
    response='0';  	// set response to wrong
    hits=0;        	// used to count hits
    questions=0;   	// set number of questions to 0
    questionsanswered=0;// 160525 - to fix new assess function
    
    // set all td cells in table maps to initially no background images
    var tdtags = document.getElementById("map").getElementsByTagName("td");
    for (var i = 0; i < tdtags.length; i++)
        {tdtags[i].style.backgroundImage = "none";}
     
     // 1 create an array 16 square ids
     squareid=['a1','b1','c1','d1','a2','b2','c2','d2','a3','b3','c3','d3','a4','b4','c4','d4'];   
     
     // Initially load a letter x into each cell 
     for(var i=0; i<=15; i++) 
        {document.getElementById(squareid[i]).innerHTML='x';}
        
     // Randomise location of objects   
         
     // 1st select 7 cells at random to use
     // now generate unique randoms between 1 and maxterms and stores them in an array called cells[]
     //generate unique randoms between 1 and maxterms and stores them in an array called cells[]
     maxrandomvalue=16;
     cells = new Array(); //declare an array called cells
  
     for(var i=0; i<maxrandomvalue; i++) 
        {randomnumber=Math.ceil(Math.random()*maxrandomvalue)
         match=0;
         for (j=-1;j<=i;j++)
  	     {  // check if number is  already in array 
  	      if (cells[j]==randomnumber)
  	         { //alert('duplicate');
  	            match=1;  //duplicate flag
  	            i=i-1;
  	            j=i;
  	         } //stop looking, we have a duplicate
  	     }
         if(match != 1){cells[i]=randomnumber}	     
        }   // end of unique numbers code
 
 // now load objects into random locations, 2S 3B 2M
      document.getElementById(squareid[cells[0]-1]).innerHTML='S'; 
      document.getElementById(squareid[cells[1]-1]).innerHTML='S';   
      document.getElementById(squareid[cells[2]-1]).innerHTML='B'; 
      document.getElementById(squareid[cells[3]-1]).innerHTML='B';       
      document.getElementById(squareid[cells[4]-1]).innerHTML='B';   
      document.getElementById(squareid[cells[5]-1]).innerHTML='M'; 
      document.getElementById(squareid[cells[6]-1]).innerHTML='M'; 
 
    // now hide all text in spans
    document.getElementById('a1').style.visibility='hidden';
    document.getElementById('b1').style.visibility='hidden';
    document.getElementById('c1').style.visibility='hidden';
    document.getElementById('d1').style.visibility='hidden';
    document.getElementById('a2').style.visibility='hidden';
    document.getElementById('b2').style.visibility='hidden';
    document.getElementById('c2').style.visibility='hidden';
    document.getElementById('d2').style.visibility='hidden';
    document.getElementById('a3').style.visibility='hidden';
    document.getElementById('b3').style.visibility='hidden';
    document.getElementById('c3').style.visibility='hidden';
    document.getElementById('d3').style.visibility='hidden';
    document.getElementById('a4').style.visibility='hidden';
    document.getElementById('b4').style.visibility='hidden';
    document.getElementById('c4').style.visibility='hidden';
 document.getElementById('d4').style.visibility='hidden';
 displayinstructions();
}

function shakeup(){
   // function by <chris.wright@ mail.com> to shuffle the answers in some QGM games
   // input array testsplit[], [0]=Question, [1]-[4]=possible answers, [5]=key A-D to correct answer
   var abcde="ABCDE";
   var i // need to declare this to protect other counters
   for(i=1; i<=distractornum; i++)
      {
       var aa=testsplit[distractornum+1]; //the original answer position
       var x=aa.charCodeAt(0)-64; // convert ASCII code for answer into number in range 1-4
       var newplace=Math.ceil(Math.random()*distractornum);
       var temp=testsplit[newplace];
       testsplit[newplace]=testsplit[i];
       testsplit[i]=temp; //swap index with newplace
       if(i==x){testsplit[distractornum+1]=abcde.substring(newplace-1,newplace);}
       // if moving the answer, correct the answer flag
       if(newplace==x){testsplit[distractornum+1]=abcde.substring(i-1,i);} 
      }
}

function loadquestions(){
   // build questions and distractors into a string and randomise location of correct answer
   // 160625 - rewrite to match revelation game
   selectstring='';
   for (var i=0;i<maxterms;i++)  //loop through questions
       {
        stem='q'+(i+1);  //build stem id

        // build stem and start select boxes
        selectstring=selectstring+"<span id='"+stem+"'>"+stemarray[i]+"</span> ";
        selectstring=selectstring+"<select onchange='assess(this);' size='1' onfocus='unselected(this)' ";
        selectstring=selectstring+"id='question"+i+"'>";
        selectstring=selectstring+"<option value='0'></option>";

        // build the distractors A to D - 1st check if distractor is correct answer
        if (answer[i]=="A"){value=1} else{value=0}
        optionA="<option value='"+value+"'>"+adistract[i]+"</option>\n";

        if (answer[i]=="B"){value=1} else{value=0}
        optionB="<option value='"+value+"'>"+bdistract[i]+"</option>\n";

        if (answer[i]=="C"){value=1} else{value=0}
        optionC="<option value='"+value+"'>"+cdistract[i]+"</option>\n";

        if (answer[i]=="D"){value=1} else{value=0}
        optionD="<option value='"+value+"'>"+ddistract[i]+"</option>\n";

        optionE='';  //initialise possible 5th option as empty string
        // if edistract exists in this question add it as an option
        if(typeof edistract[i]=='string')
          { 
           if (answer[i]=="E"){value=1} else{value=0}
           optionE="<option value='"+value+"'>"+edistract[i]+"</option>\n";
          }

        // add tail if tail doesn't exist in question let it be empty string
        if(typeof tail[i]!='string'){tail[i]='';}

        selectstring=selectstring+optionA+optionB+optionC+optionD+optionE+"</select> "+tail[i]+"<br />\n";
       }
   document.getElementById('questionsdiv').innerHTML=selectstring;
}

function uniques(){
   //generate unique randoms between 1 and maxterms and stores them in an array called numbers[]

  for(var i=1; i<=maxterms; i++)
     {randomnumber=Math.ceil(Math.random()*maxterms)
       match=0;
       for (j=-1;j<i;j++)
           {  // check if number is  already in array
	        if (numbers[j]==randomnumber)
	           { //alert('duplicate');
	            match=1;  //duplicate flag
	            i=i-1;
	            j=i;} //stop looking, we have a duplicate
	       }
       if(match != 1){numbers[i]=randomnumber}

     }   // end of unique numbers code
}


// The unselected function stops users from changing a selected answer
// It is called by an onfocus event. If an answer was picked it focus is sent to the resetbutton

function unselected(x){
   if(response=='1') //check the player has fired their correct answer shot 
      {document.getElementById('resetbutton').focus(); //make drop box lose focus by focussing elsewhere
       alertboxer('<h1>Information</h1><p>You must Click a Cell on the Map to continue.</p>');
       } 
   else{
        if (x.selectedIndex !=0)
           {document.getElementById('resetbutton').focus(); //make drop box lose focus by focussing elsewhere
            alertboxer('<h1>Information</h1><p>Your Answer is Locked in and cannot be changed !</p>');
           }
       }
}

function assess(answer){             // assess a selected response
 // First we blur the current object to lock in the answer
 // we force loss of focus to prevent changes by focusing on the reset button
    document.getElementById('resetbutton').focus(); 
      
    // answer = this,  passed from onChange event by user selection
    // stores option value, 1 or 0  in variable   response
   // response = answer.options[answer.selectedIndex].value;
   response = answer.value;
    var message='';

   // 160525 - get correct answer option and its text
   actualanswer=document.getElementById(answer.id).querySelector('option[value="1"]').value;
   correcttext=document.getElementById(answer.id).querySelector('option[value="1"]').text;
   
   questionsanswered=questionsanswered+1; //increase number answered so far
    
    //check response, increment score if correct and display result
      if (response=='1')
         {soundplayer('correct1');
          answer.style.color='green';
          alertboxer("<h1>Correct</h1><p><img src='tick.gif' alt='tick' /><br /> Click on a Cell on the Map</p>");
         }
    else
         {soundplayer('wrong1');
          answer.style.color='red';
          alertboxer("<h1>Incorrect</h1><p><img src='cross.gif' alt='wrong' /></p>The Correct Answer was<p class='correctanswer'>"+correcttext+"</p><br />Try the Next Question !"); 
          if (questionsanswered==ammo&&hits!=numships){outofammo();}   // got it wrong check if out of ammo         
         }

}

function outofammo(){
   alertboxer('<h1>Information</h1><p>You\'re out of Shots '+gametext[1]+' !,<br /> Hit the New Game button to Play Again</p>');
   playagain();
}


function allowplay(x){
 // is player allowed a turn ?
 // only if question answered correctly and before another question is asked
   if(response=='1')  // correct answer
       {// allowed a turn, has cell been targeted before
         if(document.getElementById(x).style.visibility=='visible')
              {alertboxer('<h1>Information</h1><p>This Cell has already been Attacked.<br />Try another</p>');}
         else {// showexplosion(x);
               // keep all cell html while displaying explosion
               cellcontents=document.getElementById(x).parentNode.innerHTML;
               fireshot(x);
               
               soundplayer('explode');
               response='0'; // reset response so must fire before answering another question
              }
       }
   else{
        alertboxer('<h1>Information</h1><p>'+gametext[1]+'<br />You must answer a Question<br />before you can Click on the Map!</p>');
       }
 
}

/* 180625 - removed explosion gif
function showexplosion(x){
  // keep all cell html while displaying explosion
  cellcontents=document.getElementById(x).parentNode.innerHTML;
  
  document.getElementById('cell'+x).style.backgroundColor='black';
  document.getElementById('cell'+x).innerHTML="<img src='smallexplosion.gif' alt=''/>";
  
  ship=x;  // keep span id
  timer=setTimeout("fireshot(ship)",1200);
}
*/

function fireshot(x){
  document.getElementById('cell'+x).innerHTML=cellcontents;  //put html back
  document.getElementById('cell'+x).style.backgroundColor='transparent';
  document.getElementById(x).style.visibility="visible"; // make ship letter visible
  
  // make image fit cell
  document.getElementById('cell'+x).style.backgroundSize='contain'; 
  
     if (document.getElementById(x).innerHTML=="B")
        {alertboxer("<h1>Congratulations</h1><p>Excellent, You destroyed a "+gametext[4]+"</p><img src='"+gameimages[0]+"' />");
         document.getElementById('cell'+x).style.background='url('+gameimages[0]+') no-repeat center';
         document.getElementById('cell'+x).style.backgroundSize='contain';
         document.getElementById(x).innerHTML='';
        }
     if (document.getElementById(x).innerHTML=="M")
        {alertboxer("<h1>Congratulations</h1><p>You destroyed a "+gametext[5]+"</p><img src='"+gameimages[1]+"' />");
         document.getElementById('cell'+x).style.background='url('+gameimages[1]+') no-repeat center';
         document.getElementById('cell'+x).style.backgroundSize='contain';         
         document.getElementById(x).innerHTML='';
        }
     if (document.getElementById(x).innerHTML=="S")
        {alertboxer("<h1>Congratulations</h1><p>You destroyed a "+gametext[6]+"</p><img src='"+gameimages[2]+"' />");
         document.getElementById('cell'+x).style.background='url('+gameimages[2]+') no-repeat center';
         document.getElementById('cell'+x).style.backgroundSize='contain';
         document.getElementById(x).innerHTML='';
        }
     if (document.getElementById(x).innerHTML=="x")
        { alertboxer("<h1>Information</h1><br /><p><img src='shot.png' alt='wrong' /></p><p>You Missed !</p>");
        document.getElementById('cell'+x).style.background='url("shot.png") no-repeat center';
        document.getElementById(x).innerHTML=' ';  // misses hold a single space
        }

     // Is the enemy destroyed  - count hits of empty cells holding only a space has an object
     if (document.getElementById(x).innerHTML=="")
        {hits=hits+1;
         if (hits>=numships)
            {message='';
             message='<h1>Congratulations</h1><p>The '+gametext[0]+' is destroyed.<br />';
             message=message+' Congratulations on your promotion to '+gametext[3]+' !<br /> Hit the New Game button to Play Again</p>';
             alertboxer(message);
             playagain()
            }
        }    
        
      if (questionsanswered==ammo&&hits < numships)  //  we are out of ammo
         {outofammo();} 

}

function playagain(){
        // make resetbox full screen and display play again button
          document.getElementById('resetbox').style.width=document.body.clientWidth+'px';
          document.getElementById('resetbox').style.height=document.body.clientHeight+'px';
          document.getElementById('resetbox').style.display='block';
          document.getElementById('resetbutton').style.display='block';
}

function soundplayer(x){  // use new html audio tag to play mp3's
   document.getElementById("sndplayer").src=x+".mp3";
   document.getElementById("sndplayer").play();
}

function displayinstructions(){
  if(document.getElementById('instructions').style.display=='block')
      {$("#instructions").slideUp("normal");}
  else{$("#instructions").slideDown("normal");}
}

function doafterclose(){ //after alertboxer closes
   // add pulser class via js once alertbox closes
 //     document.getElementById('instructionslink').className='boxes';
}