function Mind() {
  var exploredPosition;
  var deadEnd;
  const axis = [
    [0, -1],	[1, 0], [0, 1], [-1, 0]
  ];

  this.newRun = function()
  {
    exploredPosition = [];
    deadEnd = {};
  };

  this.endRun = function()
  {
  };

  // x: ai position in x
  // y: ai position in x
  // env: array of information for each direction (.open = no wall)
  this.getAction = function (state)
  {
    console.log(state, exploredPosition, deadEnd);
    for (var i = 0; i < state.env.length; i++) {
      if (!state.env[i].open)
        continue;
      var a = {
        x: state.x + axis[i][0],
        y: state.y + axis[i][1],
      };
      if (typeof(deadEnd[a.x.toString() + 'x' + a.y.toString()]) == 'undefined' &&
        typeof(exploredPosition.find(function (b) { return a.x == b.x && a.y == b.y; })) == 'undefined') {
        exploredPosition.unshift(a);
        return a;
      }
    }
    if (exploredPosition.length > 0)
      deadEnd[exploredPosition[0].x.toString() + 'x' + exploredPosition[0].y.toString()] = true;
    if (exploredPosition.length < 2) { // no exit found, wtf append ?
      this.endRun();
      return state;
    }
    exploredPosition.shift();
    return exploredPosition[0];
  };
}