intro exercise

robot.rb

# Time to complete: 40 minutes

class Robot
  attr_accessor :position, :items, :health, :equipped_weapon

  def initialize
    @position = [0,0]
    @items = []
    @health = 100
  end

  def move_left
    position[0] -= 1
  end

  def move_right
    position[0] += 1
  end

  def move_up
    position[1] += 1
  end

  def move_down
    position[1] -= 1
  end

  def pick_up(item)
    if items_weight >= 250
      raise ArgumentError
    else
      items << item
    end
  end

  def items_weight
    items.inject(0) { |sum, item| sum += item.weight }
  end

  def wound(hit)
    hit >= @health ? @health = 0 : @health -= hit
  end

  def heal(life)
    (life + @health) >= 100 ? @health = 100 : @health += life
  end

  def attack(robot)
    equipped_weapon ? equipped_weapon.hit(robot) : robot.wound(5)
  end
end

class Item
  attr_reader :name, :weight

  def initialize(name, weight)
    @name, @weight = name, weight
  end
end

class Bolts < Item
  def initialize
    super("bolts", 25)
  end

  def feed(robot)
    robot.heal(weight)
  end
end

class Weapon < Item
  attr_accessor :damage

  def initialize(name, weight, damage)
    @name, @weight, @damage = name, weight, damage
  end

  def hit(robot)
    robot.wound(damage)
  end
end

class Laser < Weapon
  def initialize
    super("laser", 125, 25)
  end
end

class PlasmaCannon < Weapon
  def initialize
    super("plasma_cannon", 200, 55)
  end
end