Fight Code Game robot barebones statemachine bots

state-bot.js

// Store all of the robots and their states so
// that they can be referenced throughout the robots
var ROBOT_STATES = {}

// states

// find and attack enemy with reckless abandon
var SEEK = {
  onIdle: function(ev) {
    ev.robot.turn(360);
  },
  onScannedRobot: function(ev) {
    changeState(ev.robot, DESTROY);
  }
}

var DESTROY = {
  onIdle: function(ev) {
  	changeState(ev.robot, SEEK);
  },
  onScannedRobot: function(ev) {
    if (friends(ev.robot, ev.scannedRobot)) {
      return;
    }
    ev.robot.move();
    ev.robot.fire(); 
  }
}

// common state behavior

function friends(robot1, robot2) {
  return robot1.parentId == robot2.id || robot1.id == robot2.parentId;
}

// wiring robots to states 

var Robot = function(robot) { robot.clone(); }

Robot.prototype.onIdle = function(ev) {
  state(ev.robot).onIdle(ev);
};

Robot.prototype.onScannedRobot = function(ev) {
  state(ev.robot).onScannedRobot(ev);
};

Robot.prototype.onHitByBullet = function(ev) {
  state(ev.robot).onHitByBullet(ev);
};

Robot.prototype.onWallCollision = function(ev) {
  state(ev.robot).onWallCollision(ev);
};

Robot.prototype.onRobotCollision = function(ev) {
  state(ev.robot).onRobotCollision(ev);
};

// state machine

function changeState(robot, state) {
  ROBOT_STATES[robot] = state;
  bindEvents(robot, state);
}

function bindEvents(robot, state) { 
  var all_events = [
    'onIdle',
    'onScannedRobot',
    'onRobotCollision',
    'onWallCollision',
    'onHitByBullet'
  ];
  for (var event in all_events) {
    if (event in state) {
      robot.listen(event);
    } else {
      robot.ignore(event);
    }
  }
}

function determineFirstState(robot) {
  return SEEK;
}

function state(robot) {
  if (!(robot in ROBOT_STATES)) {
    // set up initial state
    ROBOT_STATES[robot] = determineFirstState(robot);
  }
  return ROBOT_STATES[robot];
}