(function (global) {
  var keys = {
    LEFT: 37,
    UP: 38,
    RIGHT: 39,
    DOWN: 40,
    ENTER: 13,
    BACK: 10009,
    ESC: 27,
    PLAY: 415,
    PAUSE: 19,
    PLAYPAUSE: 10252,
    FF: 417,
    REW: 412,
    STOP: 413,
  };

  function visibleFocusables(root) {
    root = root || document;
    var nodes = root.querySelectorAll(".focusable, .tile, .profile-tile, .ep, .num-key, .btn");
    var out = [];
    for (var i = 0; i < nodes.length; i++) {
      var el = nodes[i];
      if (el.disabled) continue;
      if (el.classList.contains("hidden")) continue;
      if (el.closest && el.closest(".hidden")) continue;
      var r = el.getBoundingClientRect();
      if (r.width < 2 || r.height < 2) continue;
      out.push(el);
    }
    return out;
  }

  function center(el) {
    var r = el.getBoundingClientRect();
    return { x: r.left + r.width / 2, y: r.top + r.height / 2, r: r };
  }

  function move(direction) {
    var active = document.activeElement;
    var list = visibleFocusables();
    if (!list.length) return;
    if (!active || list.indexOf(active) < 0) {
      list[0].focus();
      return;
    }
    var a = center(active);
    var best = null;
    var bestScore = Infinity;

    for (var i = 0; i < list.length; i++) {
      var el = list[i];
      if (el === active) continue;
      var b = center(el);
      var dx = b.x - a.x;
      var dy = b.y - a.y;
      var ok = false;
      if (direction === "left") ok = dx < -10 && Math.abs(dy) < Math.abs(dx) * 1.6;
      if (direction === "right") ok = dx > 10 && Math.abs(dy) < Math.abs(dx) * 1.6;
      if (direction === "up") ok = dy < -10 && Math.abs(dx) < Math.abs(dy) * 1.8;
      if (direction === "down") ok = dy > 10 && Math.abs(dx) < Math.abs(dy) * 1.8;
      if (!ok) continue;
      var score = Math.abs(dx) + Math.abs(dy) * 1.2;
      if (score < bestScore) {
        bestScore = score;
        best = el;
      }
    }
    if (best) {
      best.focus();
      if (best.scrollIntoView) best.scrollIntoView({ block: "nearest", inline: "nearest" });
    }
  }

  function registerKeys() {
    try {
      if (global.tizen && tizen.tvinputdevice) {
        var supported = tizen.tvinputdevice.getSupportedKeys() || [];
        var names = ["MediaPlay", "MediaPause", "MediaPlayPause", "MediaFastForward", "MediaRewind", "MediaStop"];
        for (var i = 0; i < supported.length; i++) {
          if (names.indexOf(supported[i].name) >= 0) {
            try {
              tizen.tvinputdevice.registerKey(supported[i].name);
            } catch (e) {}
          }
        }
      }
    } catch (e) {}
  }

  global.McFocus = {
    keys: keys,
    move: move,
    focusFirst: function (root) {
      var list = visibleFocusables(root);
      if (list[0]) list[0].focus();
    },
    registerKeys: registerKeys,
  };
})(window);