var emptyloc=4
var noleft=new Array(0, 5, 10, 15)
var noright=new Array(4, 9, 14, 19)
var mup = -1
var mdown = 9
var mleft = 3
var mright = -1
var picfld = "p1"

function initval()
{
emptyloc=4
mup = -1
mdown = 9
mleft = 3
mright = -1
}


function movepiece(input)
{

var selected=input

//checks if selected move is allowed
var allowed="no"
if (selected==mup){allowed="yes"}
if (selected==mdown){allowed="yes"}
if (selected==mleft){allowed="yes"}
if (selected==mright){allowed="yes"}
if (allowed=="no")
{
    alert("Špatný tah! Lze posouvat pouze čtverečky, které sousedí s volným místem.")
}
else
{
    var tomove = document.getElementById("puzzle_"+selected).src
    document.getElementById("puzzle_"+selected).src="images/em.gif"
    document.getElementById("puzzle_"+emptyloc).src=tomove
    emptyloc=selected








    // This section sets new allowed moves after tiles are moved
    var restrict="none"
    for (var i = 0; i < 4; i++)
    {
	if (noleft[i]==input)
        {
	    restrict="left"
        }
        if (noright[i]==input)
        {
	    restrict="right"
        }
    }

    mup=selected - 5
    mdown=selected + 5
    if (restrict=="left")
    {
        mleft= -1
    }
    else
    {
        mleft= selected -1
    }
    if (restrict=="right")
    {
        mright= -1
    }
    else
    {
        mright= selected + 1
    }
    checkwin()
}

}


function checkwin()
{
var winval = 0
var srcval = 0
var tmpval = 0

//alert("TEST: "+picfld)

for (var i = 0; i < 20; i++)
{
        
    if (i < 10)
    {
	tempval = document.getElementById("puzzle_"+i).src.charAt(document.getElementById("puzzle_"+i).src.length - 5)
    }
    else
    {
	tempval = document.getElementById("puzzle_"+i).src.charAt(document.getElementById("puzzle_"+i).src.length - 6) + document.getElementById("puzzle_"+i).src.charAt(document.getElementById("puzzle_"+i).src.length - 5)
    }

    if (tempval==i)
    {
	winval++
    }
}
if (winval==19)
{
    alert("Gratuluju! Vyřešil si puzzle.")
    document.getElementById("puzzle_4").src = picfld + "/4.jpg"
    mup = -1
    mdown = -1
    mleft = -1
    mright = -1

}

}


function showsolve()
{
window.open(picfld + "/fullimg.jpg","_puzsol","height=276,innerHeight=276,width=340,innerWidth=340,toolbar=0,left=0,screenX=0,top=0,screenY=0")
}


function newpic(picno)
{

for (var i=0;i<20;i++)
{
document.getElementById("puzzle_"+i).src = "images/em.gif"
}


if (picno==1)
{
    picfld = "p" + picno
    var seq = new Array(10, 6, 7, 12, 4, 1, 13, 3, 5, 18, 0, 11, 9, 8, 19, 15, 16, 14, 2, 17)
    for (var i = 0; i < 20; i++)
    {
        document.getElementById("puzzle_"+i).src = picfld + "/" + seq[i] + ".jpg"


    }
document.getElementById("puzzle_4").src = "images/em.gif"
initval()
document.getElementById("puzzle_20").src = "images/puz1s.gif"
document.getElementById("puzzle_21").src = "images/puz2.gif"
document.getElementById("puzzle_22").src = "images/puz3.gif"
document.getElementById("puzzle_23").src = "images/puz4.gif"
}

if (picno==2)
{
    picfld = "p" + picno
    var seq = new Array(1, 7, 16, 3, 4, 11, 5, 12, 10, 14, 6, 0, 15, 9, 19, 13, 18, 8, 2, 17)
    for (var i = 0; i < 20; i++)
    {
        document.getElementById("puzzle_"+i).src = picfld + "/" + seq[i] + ".jpg"

    }
document.getElementById("puzzle_4").src = "images/em.gif"
initval()
document.getElementById("puzzle_20").src = "images/puz1.gif"
document.getElementById("puzzle_21").src = "images/puz2s.gif"
document.getElementById("puzzle_22").src = "images/puz3.gif"
document.getElementById("puzzle_23").src = "images/puz4.gif"
}

if (picno==3)
{
    picfld = "p" + picno
    var seq = new Array(11, 7, 12, 16, 4, 6, 5, 1, 14, 19, 18, 15, 2, 9, 3, 0, 13, 8, 17, 10)
    for (var i = 0; i < 20; i++)
    {
        document.getElementById("puzzle_"+i).src = picfld + "/" + seq[i] + ".jpg"
    }
document.getElementById("puzzle_4").src = "images/em.gif"
initval()
document.getElementById("puzzle_20").src = "images/puz1.gif"
document.getElementById("puzzle_21").src = "images/puz2.gif"
document.getElementById("puzzle_22").src = "images/puz3s.gif"
document.getElementById("puzzle_23").src = "images/puz4.gif"
}

if (picno==4)
{
    picfld = "p" + picno
    var seq = new Array(11, 5, 9, 7, 4, 0, 14, 19, 10, 12, 8, 6, 17, 3, 1, 2, 16, 18, 15, 13)
    for (var i = 0; i < 20; i++)
    {
        document.getElementById("puzzle_"+i).src = picfld + "/" + seq[i] + ".jpg"
    }
document.getElementById("puzzle_4").src = "images/em.gif"
initval()
document.getElementById("puzzle_20").src = "images/puz1.gif"
document.getElementById("puzzle_21").src = "images/puz2.gif"
document.getElementById("puzzle_22").src = "images/puz3.gif"
document.getElementById("puzzle_23").src = "images/puz4s.gif"
}

}