var height = 10;
var width = 10;
var winLenght = 5;

var player = 'X';
var winCounter = 0; // pocitadlo viteznych policek po sobe jdoucich


function start() {
    createGameArena();

}

// --------------- vytvoření herního pole ----------------- //
function createGameArena() {

    var gameDiv = document.getElementById('game');
    var table = document.createElement('table');

    for (var i = 0; i < height; i++) {
        var tr = document.createElement('tr');
        for (var j = 0; j < width; j++) {
            var td = document.createElement('td');
            td.id = j + 'x' + i;
            td.X = j;
            td.Y = i;

            td.addEventListener('click', clickToNode);

            tr.appendChild(td);
        }
        table.appendChild(tr);
    }
    gameDiv.appendChild(table);


}

function clickToNode(e) {

    /**
     *
     * @type Element element
     */
    var element = e.toElement;
    element.textContent = player;


    // funkce na kontrlu smeru

    checkLeftRight(element);
    checkUpBottom(element);
    checkDiagonalLeftUpToRightBottom(element);
    checkDiagonalRightUpToLeftBottom(element);

    switchPlayer();

}

function checkLeftRight(rootElement) {

   var rightElement = getRightElement(rootElement)
   while(rightElement != null && rightElement.textContent == player){
       rightElement = getRightElement(rightElement);
       winCounter++;
   }

   var leftElement = getLeftElement(rootElement);
   while(leftElement != null && leftElement.textContent == player){
       leftElement = getLeftElement(leftElement);
       winCounter++;
   }

   if(winCounter + 1 == winLenght){
        gameOver();
   }

   winCounter = 0;
}

function checkUpBottom(rootElement) {


var topElement = getTopElement(rootElement)
   while(topElement != null && topElement.textContent == player){
       topElement = getTopElement(topElement);
       winCounter++;
   }

   var bottomElement = getBottomElement(rootElement);
   while(bottomElement != null && bottomElement.textContent == player){
       bottomElement = getBottomElement(bottomElement);
       winCounter++;
   }

   if(winCounter + 1 == winLenght){
        gameOver();
   }

   winCounter = 0;


}

function checkDiagonalLeftUpToRightBottom(rootElement) {

var topLeftElement = getTopLeftElement(rootElement)
   while(topLeftElement != null && topLeftElement.textContent == player){
       topLeftElement = getTopLeftElement(topLeftElement);
       winCounter++;
   }

   var bottomRightElement = getBottomRightElement(rootElement);
   while(bottomRightElement != null && bottomRightElement.textContent == player){
       bottomRightElement = getBottomRightElement(bottomRightElement);
       winCounter++;
   }

   if(winCounter + 1 == winLenght){
        gameOver();
   }

    winCounter = 0;
}

function checkDiagonalRightUpToLeftBottom(rootElement) {

var topRightElement = getTopRightElement(rootElement)
   while(topRightElement != null && topRightElement.textContent == player){
       topRightElement = getTopRightElement(topRightElement);
       winCounter++;
   }

   var bottomLeftElement = getBottomLeftElement(rootElement);
   while(bottomLeftElement != null && bottomLeftElement.textContent == player){
       bottomLeftElement = getbottomLeftElement(bottomLeftElement);
       winCounter++;
   }

   if(winCounter + 1 == winLenght){
        gameOver();
   }


    winCounter = 0;
}

function gameOver() {
    alert("game over, vyhrál " + player);
}


// ------------------------------------------------------------------

function switchPlayer() {
    if (player == 'X')
        player = 'O';
    else
        player = 'X';
}

function getTopElement(rootElement) {
    var topElementId = rootElement.X + 'x' + (rootElement.Y - 1);
    return document.getElementById(topElementId);
}

function getBottomElement(rootElement) {
    var bottomElementId = rootElement.X + 'x' + (rootElement.Y + 1);
    return document.getElementById(bottomElementId);
}

function getLeftElement(rootElement) {
    var leftElementId = (rootElement.X - 1) + 'x' + rootElement.Y;
    return document.getElementById(leftElementId);
}

function getRightElement(rootElement) {
    var rightElementId = (rootElement.X + 1) + 'x' + rootElement.Y;
    return document.getElementById(rightElementId);
}

function getTopLeftElement(rootElement) {
    var topLeftElementId = (rootElement.X - 1) + 'x' + (rootElement.Y - 1);
    return document.getElementById(topLeftElementId);
}

function getTopRightElement(rootElement) {
    var topRitghtElementId = (rootElement.X + 1) + 'x' + (rootElement.Y - 1);
    return document.getElementById(topRitghtElementId);
}

function getBottomLeftElement(rootElement) {
    var bottomLeftElementId = (rootElement.X - 1) + 'x' + (rootElement.Y + 1);
    return document.getElementById(bottomLeftElementId);
}

function getBottomRightElement(rootElement) {
    var bottomRightElementId = (rootElement.X + 1) + 'x' + (rootElement.Y + 1);
    return document.getElementById(bottomRightElementId);
}




// ----------- debugovací funkce ---------------- //

function lookAround(element) {
    console.log('left:');
    console.log(getLeftElement(element));
    console.log('right:');
    console.log(getRightElement(element));
    console.log('top:');
    console.log(getTopElement(element));
    console.log('bottom:');
    console.log(getBottomElement(element));
    console.log('top left:');
    console.log(getTopLeftElement(element));
    console.log('top right:');
    console.log(getTopRightElement(element));
    console.log('bottom left:');
    console.log(getBottomLeftElement(element));
    console.log('bottom right:');
    console.log(getBottomRightElement(element));
}