tic tac toe bot

bot.js

var last = function(arr) {
  return arr[arr.length - 1];
}

var coordinate1 = function(state) {
  return last(state["history"])["move"][1];
}

var firstFromSquare = function(square_arr){
  for(var i = 0; i < square_arr.length; i++){
    if(square_arr[i] == null){
      return i;
    }
  }
  return null;
}

var firstFromBoard = function(grid) {
  for(var i = 0; i < grid.length; i++) {
    for(var j = 0; j < grid[i].length; j++) {
      if(grid[i][j] == null) {
        return [i, j];
      }
    }
  }
}

var squareWon = function(square) {
  var opts = [[0, 1, 2], [0, 4, 8], [0, 3, 6], [1, 4, 7], [2, 5, 8], [2, 4, 6], [3, 4, 5], [6, 7, 8]]
  var won = false;
  for(var i = 0; i < opts.length; i++) {
    var o = opts[i];
    if(square[o[0]] != null && square[o[0]] == square[o[1]] && square[o[0]] == square[o[2]]) {
      return true;
    }
  };
  return false;
}

var bot = function(state) {
  // if we are player one, play [2, 2]
  if(state["history"].length == 0) {
    return [2, 2];
  } else {
    var c1 = coordinate1(state);
    var c2 = firstFromSquare(state["grid"][c1]);

    if(c2 == null || squareWon(state["grid"][c1])) {
      return firstFromBoard(state["grid"]);
    } else {
      return [c1, c2];
    }
  }
}



// PASTE ABOVE


var arr_to_string = function(arr) {
 return "["+arr[0]+" "+arr[1]+"]";
}

var actual_bot = function(edn_state) {
  var state = edn_to_json(edn_state);
  return arr_to_string(bot(state));
}

actual_bot;