var pool_size = 8;
var selected = [];
var score = 0;

var binaryString = function (int) {
    // prints and pads, used to display dots
    binary_string = int.toString(2);
    while (binary_string.length < 6){
        binary_string = '0' + binary_string;
    }
    return binary_string;
};

var create_deck = function () {
    //just an array from 1 to 64
    unshuffled_deck = [];
    var i = 1; // Stewart Stewart says: The trivial card is too trivial (exclude the blank card, 64 (2^6) permutations but 63 cards)
    while (i < 64){
        unshuffled_deck.push(i);
        i ++;
    }
    return unshuffled_deck;
};

var shuffle = function (unshuffled_deck) {
    shuffled_deck = [];
    while (unshuffled_deck.length>0){
        randInt = Math.floor(Math.random() * (unshuffled_deck.length));
        shuffled_deck.push(unshuffled_deck.splice(randInt,1)[0]);
    }
    return shuffled_deck;
};

var deal = function (shuffled_deck, pool, index) {
    pool[index] = null;
    if (shuffled_deck){
        // removes card from deck display
        $('div#deck > div:first').remove();

        // adds card from deck into corect index
        pool[index]=shuffled_deck.pop();
        return pool;
    }
};

var game_over = function (pool){
    for (var i = 0; i < pool.length; i++){
        if (pool[i]){
            return false;
        }
    }
    return true;
};

var display = function (pool, deck) {
    // turns css on and off
    var wrapper = document.getElementById("wrapper");
    for (var i = 0; i < pool.length; i++) {
        // if card has been dealt
        if (pool && pool[i]){
            var binary_string = binaryString(pool[i]);
            for (var j = 0; j < 6; j ++) {
                var card_id_and_dot = 'div.card' + '#' + i + ' .dot' + ':eq(' + j + ')' ;
                if (binary_string[j] == 0) {
                    $(card_id_and_dot).removeClass('on').addClass('off');
                }
                else {
                    $(card_id_and_dot).removeClass('off').addClass('on');
                }
            }
        }else{
            // turn card off
            $('div.card#'+i).addClass('off');
            $('div.card#'+i+"> .dot").addClass('off');
        }
    }
};


var check = function (id) {
    // poorly named function
    
    // if card is selected, deselect it. Else, select it.
    var index = $.inArray(pool[id], selected); //returns -1 if not in array
    if (index != -1) {
        selected.splice(index, 1);
        $('#'+ id).removeClass('selected');
    }
    else {
        selected.push(pool[id]);
        $('#'+ id).addClass('selected');
    }
    var binary_string = binaryString(my_xor(selected));
    for (var j = 0; j < 6; j ++) {
        var card_id_and_dot = 'div.card' + '#result .dot' + ':eq(' + j + ')' ;
        if (binary_string[j] == 0) {
            $(card_id_and_dot).removeClass('on').addClass('off');
        }
        else {
            $(card_id_and_dot).removeClass('off').addClass('on');
        }
    }

    // once we've selected at least three cards and if they're a set
    if (selected.length > 2){
        if (my_xor(selected) == 0) {
            for (var i = 0; i < selected.length; i ++) {
                // find all the selected cards indices in the pool
                var index = $.inArray(selected[i], pool); //have to find them all again, this is dumb
                // flash them to indicate a set
                $('#'+ index).fadeOut(150).fadeIn(150).removeClass('selected');
                // deal new cards
                deal(shuffled_deck, pool, index);
            }
            setTimeout(function() { display(pool, deck); }, 150); //wait until fadeout/in is finished to display newly dealt cards
            selected = [];
            increment_score();
        }
    }

    if (game_over(pool)){
        document.body.innerHTML = "<h1 id='game-over'>GAME OVER!</h1><h2>You found " + score + " sets.</h2>";
    }
};

var my_xor = function (list) {
    // regular xor for each card in the list
    if (list.length > 0) {
        var result = list[0];
        for (var i = 1; i < list.length; i ++) {
            result = result ^ list[i];
        }
        return result;
    }
    return 0;
};

var helpToggle = function(on) {
    if (on){
        $('#result').removeClass("hidden");
    }
    else {
        $('#result').addClass('hidden');
    }
}

var increment_score = function () {
    score ++;
    $('#score').text(score);
};


// make a deck of number cards
var deck = create_deck();

// display a deck of card backs
for (var i = 0; i < 3; i ++){
    $('div#deck').append("<div class='card_back'></div>");
}

// shuffle your deck
var shuffled_deck = shuffle(deck);

//initialize pool of cards to choose from
var pool = [];
for (var i = 0; i < pool_size; i ++) {
    pool = deal(shuffled_deck, pool, i);
}

// display pool of cards to choose from
display(pool, deck);

// bind click events that start game
$('.table div.card').bind('click', function() {
    check($(this).attr('id'));
});

// bind click events that start game
$('#help-switch').bind('click', function() {
    helpToggle($(this).prop('checked'));
});