player.rb

class Player
  def play_turn(warrior)
    case true
      # Critical thinking
      when dying_under_attack?(warrior) then warrior.walk! :backward
      # Normal processing
      when should_pivot?(warrior)       then warrior.pivot!
      # Can we shoot it?
      when can_shoot?(warrior)          then warrior.shoot!
      # Need to rest?
      when should_rest?(warrior)        then warrior.rest!
      # Can we go closer?
      when can_walk?(warrior)           then warrior.walk!
      # Let's rescue what could be rescued....
      when can_rescue?(warrior)         then warrior.rescue!
      # And kill the rest
      when can_hit?(warrior)            then warrior.attack!
      # What happened?
      else raise "I don't know what to do!"
    end
    @health = warrior.health
  end
  
  #----- State checks -----

  def dying?(warrior)
    warrior.health < 7
  end
  
  def under_attack?(warrior)
    @health > warrior.health
  end
  
  def dying_under_attack?(warrior)
    dying?(warrior) && under_attack?(warrior)
  end
  
  def should_rest?(warrior)
    return false if warrior.health == 20 || under_attack?(warrior)
    # Only rest if there is an enemy somewhere and we're dying
    dying?(warrior) || warrior.look.any? { |c| c.enemy? }
  end
  
  def should_pivot?(warrior)
    cells = warrior.look
    # Do not turn around from exit
    return false if cells.any? { |c| c.stairs? }
    # Do we see a wall in front of us and no things to do?
    cells[0].wall? || (cells[0].empty? && (cells[1].wall? || (cells[1].empty? && cells[2].wall?)))
  end

  #----- Teambuilding checks -----
  
  def can_rescue?(warrior)
    warrior.feel.captive?
  end
  
  def can_hit?(warrior)
    warrior.feel.enemy?
  end
  
  def can_shoot?(warrior)
    cells = warrior.look
    # Only shoot if the enemy is far from us.
    # If he is close - come closer and hit with a sword.
    cells[0].empty? && cells[1].empty? && cells[2].enemy?
  end
  
  def can_walk?(warrior)
    warrior.feel.empty?
  end
end