wallhugger.rb

class Wallhugger < RTanque::Bot::Brain
  NAME = 'wallhugger'
  include RTanque::Bot::BrainHelper
  TURRET_FIRE_RANGE = RTanque::Heading::ONE_DEGREE * 1.0

  def tick!

    wallflower
    if (target = self.nearest_target)
      self.fire_upon(target)
    else
      self.detect_targets
    end
  end

  def wallflower
    if sensors.position.on_wall?
      command.heading = patrol_direction
      command.speed = dance
    else
      # head for the nearest wall
      command.speed = MAX_BOT_SPEED
      command.heading = find_nearest_wall
    end

  end

  def fire_upon(target)
    self.command.radar_heading = target.heading
    self.command.turret_heading = target.heading
    if self.sensors.turret_heading.delta(target.heading).abs < TURRET_FIRE_RANGE
      self.command.fire(1)
    end
  end

  def nearest_target
    self.sensors.radar.min { |a,b| a.distance <=> b.distance }
  end

  def detect_targets
    self.command.radar_heading = self.sensors.radar_heading + MAX_RADAR_ROTATION
    self.command.turret_heading = self.sensors.heading + RTanque::Heading::HALF_ANGLE
  end

  def find_nearest_wall
    distances = {}
    distances[RTanque::Heading::NORTH] = sensors.position.y
    distances[RTanque::Heading::SOUTH] = arena.height - sensors.position.y
    distances[RTanque::Heading::WEST]  = sensors.position.x
    distances[RTanque::Heading::EAST]  = arena.width - sensors.position.x
    closest = distances.values.min
    distances.select { |k, v| v == closest }.keys.first
  end

  def patrol_direction
    return RTanque::Heading::NORTH if sensors.position.on_left_wall?
    return RTanque::Heading::SOUTH if sensors.position.on_right_wall?
    return RTanque::Heading::EAST if sensors.position.on_top_wall?
    return RTanque::Heading::WEST if sensors.position.on_bottom_wall?
  end

  def dance
    @next_switch ||= 0
    @speed ||= MAX_BOT_SPEED

    if sensors.ticks > @next_switch
      @speed = @speed * -1
      @next_switch = sensors.ticks + rand(120) + 120
    end

    @speed
  end



end