function Timer() {
    this.t = Date.now();
}

Timer.prototype = {
    delta: function () {
        return Date.now() - this.t;
    },

    reset: function () {
        this.t = Date.now();
    }
};

var map = {
    width: 13,
    height: 13,
    data: [
        [
            ['|', '–', '–', '–', '•', '–', '–', '–', '•', '–', '–', '–', '|'],
            ['|', '*', '•', '•', '•', '•', '•', '•', '•', '•', '•', '*', '|'],
            ['|', '•', '/', '–', '•', '•', '•', '•', '•', '–', '\\', '•', '|'],
            ['|', '•', '|', '•', '•', '•', '•', '•', '•', '•', '|', '•', '|'],
            ['|', '•', '•', '•', '•', '•', '•', '•', '•', '•', '•', '•', '|'],
            ['|', '•', '|', '•', '|', ' ', ' ', ' ', '|', '•', '|', '•', '|'],
            ['|', '•', '•', '•', '•', ' ', ' ', ' ', '•', '•', '•', '•', '|'],
            ['|', '•', '|', '•', '•', '–', '–', '–', '•', '•', '|', '•', '|'],
            ['|', '•', '•', '•', '•', '•', '•', '•', '•', '•', '•', '•', '|'],
            ['|', '•', '|', '•', '•', '•', '•', '•', '•', '•', '|', '•', '|'],
            ['|', '•', '\\', '–', '•', '•', '–', '•', '•', '–', '/', '•', '|'],
            ['|', '*', '•', '•', '•', '•', '•', '•', '•', '•', '•', '*', '|'],
            ['|', '–', '–', '–', '•', '–', '–', '–', '•', '–', '–', '–', '|'],
        ]
    ]
};

var level = 0;

var dots = map.data[level].reduce(function (p, c) {
    p += c.filter(function (d) { return d == '•'}).length;
    return p;
}, 0);

var score = 0;

var player = {
    char: 'c',
    big: {
        is: false,
        duration: 5000,
        timer: null
    },
    dead: false,
    x: 6,
    y: 8,
    color: '#2196F3'
};

var enemies = [
    {
        char: '$',
        dead: false,
        x: 6,
        y: 5,
        ox: 6,
        oy: 5,
        dir: getRandomInt(0, 3),
        wait: new Timer(),
        speed: 1300,
        color: '#F44336'
    },
    {
        char: '#',
        dead: false,
        x: 7,
        y: 6,
        ox: 7,
        oy: 6,
        dir: getRandomInt(0, 3),
        wait: new Timer(),
        speed: 1000,
        color: '#9C27B0'
    },
    {
        char: '%',
        dead: false,
        x: 5,
        y: 6,
        ox: 5,
        oy: 6,
        dir: getRandomInt(0, 3),
        wait: new Timer(),
        speed: 500,
        color: '#4CAF50'
    },
    {
        char: '&',
        dead: false,
        x: 6,
        y: 6,
        ox: 5,
        oy: 6,
        dir: getRandomInt(0, 3),
        wait: new Timer(),
        speed: 300,
        color: '#795548'
    }
];

var scoreboard = document.createElement('div');
document.body.appendChild(scoreboard);

var board = document.createElement('pre');
document.body.appendChild(board);

var keys = {};
document.addEventListener('keyup', function (e) {
    keys[e.which] = true;
});

function pressed(key) {
    if (keys[key]) {
        delete keys[key];
        return true;
    }
}

function getRandomInt(min, max) {
    min = Math.ceil(min);
    max = Math.floor(max);
    return Math.floor(Math.random() * (max - min + 1)) + min;
  }

function checkBoundaries(t, loc) {
    return /\||–|\\|\//.test(loc);
}

function update() {
    if (!player.dead) {
        if (pressed(40)) { // down
            if (player.y != map.height - 1) {
                if (!checkBoundaries(player, map.data[level][player.y + 1][player.x])) player.y++;
            } else {
                player.y = 0;
            }
        }

        if (pressed(38)) { // up
            if (player.y != 0) {
                if (!checkBoundaries(player, map.data[level][player.y - 1][player.x])) player.y--;
            } else {
                player.y = map.height - 1;
            }
        }

        if (pressed(37)) { //left
            if (player.x != 0) {
                if (!checkBoundaries(player, map.data[level][player.y][player.x - 1])) player.x--;
            } else {
                player.x = map.width - 1;
            }
        }

        if (pressed(39)) { // right
            if (player.x != map.width - 1) {
                if (!checkBoundaries(player, map.data[level][player.y][player.x + 1])) player.x++;
            } else {
                player.x = 0;
            }
        }
    }

    enemies.forEach(function (enemy) {
        if (!enemy.dead && enemy.wait.delta() > (player.big.is ? enemy.speed * 2 : enemy.speed)) {
            if (enemy.dir == 0) {
                if (enemy.y != 0) {
                    if (!checkBoundaries(enemy, map.data[level][enemy.y - 1][enemy.x])) {
                        enemy.y--;
                        if (getRandomInt(0, 9) == 3) enemy.dir = getRandomInt(0, 3);
                    } else {
                        enemy.dir = getRandomInt(0, 3);
                    }
                } else {
                    enemy.y = map.height - 1;
                }
            } else if (enemy.dir == 1) {
                if (enemy.y != map.height - 1) {
                    if (!checkBoundaries(enemy, map.data[level][enemy.y + 1][enemy.x])) {
                        enemy.y++;
                        if (getRandomInt(0, 7) == 2) enemy.dir = getRandomInt(0, 3);
                    } else {
                        enemy.dir = getRandomInt(0, 3);
                    }
                } else {
                    enemy.y = 0;
                }
            } else if (enemy.dir == 2) {
                if (enemy.x != 0) {
                    if (!checkBoundaries(enemy, map.data[level][enemy.y][enemy.x - 1])) {
                        enemy.x--;
                        if (getRandomInt(0, 10) == 5) enemy.dir = getRandomInt(0, 3);
                    } else {
                        enemy.dir = getRandomInt(0, 3);
                    }
                } else {
                    enemy.x = map.width - 1;
                }
            } else if (enemy.dir == 3) {
                if (enemy.x != map.width - 1) {
                    if (!checkBoundaries(enemy, map.data[level][enemy.y][enemy.x + 1])) {
                        enemy.x++;
                        if (getRandomInt(0, 5) == 3) enemy.dir = getRandomInt(0, 3);
                    } else {
                        enemy.dir = getRandomInt(0, 3);
                    }
                } else {
                    enemy.x = 0;
                }
            }

            enemy.wait.reset();
        }

        if (!player.dead && !enemy.dead && player.x == enemy.x && player.y == enemy.y) {
            if (player.big.is) {
                score += 10;
                enemy.dead = true;
                enemy.wait.reset();
            } else {
                player.dead = true;
            }
        }

        if (enemy.dead && enemy.wait.delta() > 5000) {
            enemy.y = enemy.oy;
            enemy.x = enemy.ox;
            enemy.dead = false;
            enemy.wait.reset();
        }
    });

    if (!player.dead && map.data[level][player.y][player.x] == '*') {
        player.big.is = true;
        player.big.timer = new Timer();
        player.char = 'C';
        map.data[level][player.y][player.x] = ' ';
    }

    if (!player.dead && map.data[level][player.y][player.x] == '•') {
        score++;
        dots--;
        map.data[level][player.y][player.x] = ' ';
    }

    if (!player.dead && player.big.is) {
        if (player.big.timer.delta() > player.big.duration) {
            player.big.is = false;
            player.char = 'c';
            player.big.timer = null;
        }
    }
}

function draw() {

    while (board.lastChild) {
        board.removeChild(board.lastChild);
    }

    scoreboard.innerText = 'Score: ' + score;

    if (player.dead) {
        scoreboard.style.color = '#F44336';
        scoreboard.innerText = 'You were eat\'n! You scored ' + score + ' points!';
    }

    if (dots == 0) {
        scoreboard.style.color = '#4CAF50';
        scoreboard.innerText = 'You won! You scored ' + score + ' points!';
    }

    for (var y=0; y<map.data[level].length; y++) {

        for (var x=0; x<map.data[level][y].length; x++) {
            var node = document.createElement('span');

            node.innerText = map.data[level][y][x];
            if (map.data[level][y][x] == '•') node.style.color = '#BDBDBD';
            if (map.data[level][y][x] == '|') node.style.color = '#0D47A1';
            if (map.data[level][y][x] == '*') node.style.color = '#F57F17';

            enemies.forEach(function (enemy) {
                if (!enemy.dead && enemy.y == y && enemy.x == x) {
                    node.innerText = enemy.char;
                    node.style.color = enemy.color;

                    if (player.big.is) {
                        node.style.color = '#00BCD4';
                    }
                }
            });

            if (!player.dead && player.y == y && player.x == x) {
                node.innerText = player.char;
                node.style.color = player.color;
            }

            board.appendChild(node);
        }

        board.appendChild(document.createElement('br'));
    }


}

function loop() {
    update();
    draw();

    if (!player.dead && dots != 0) window.requestAnimationFrame(loop);
}

window.requestAnimationFrame(loop);