class Order
  def calculate_total
    # lógica para calcular o total do pedido
  end

  def save_to_db
    # lógica para salvar no banco de dados
  end

  def send_confirmation_email
    # lógica para envio de email
  end
end

class Order
  def calculate_total
    # lógica para calcular o total do pedido
  end
end

class OrderRepository
  def save(order)
    # lógica para salvar no banco de dados
  end
end

class EmailService
  def send_confirmation(order)
    # lógica para envio de email
  end
end

2. Open/Closed Principle (Princípio Aberto/Fechado)

class AreaCalculator
  def calculate(shape)
    if shape.is_a?(Square)
      shape.side * shape.side
    elsif shape.is_a?(Circle)
      Math::PI * shape.radius * shape.radius
    end
  end
end

module Shape
  def calculate_area
    raise NotImplementedError
  end
end

class Square
  include Shape
  
  def initialize(side)
    @side = side
  end
  
  def calculate_area
    @side * @side
  end
end

class Duck
  def fly
    puts "Flying"
  end
end

class RubberDuck < Duck
  def fly
    raise "Rubber duck can't fly!"
  end
end

module Flyable
  def fly
    raise NotImplementedError
  end
end

class Duck
  include Flyable
  
  def fly
    puts "Flying"
  end
end

class RubberDuck
  # Não inclui Flyable
end

module Device
  def turn_on; end
  def turn_off; end
  def volume_up; end
  def volume_down; end
end

class Television
  include Device
  # Implementa todos os métodos
end

class Lightbulb
  include Device
  def volume_up
    raise NotImplementedError
  end
  
  def volume_down
    raise NotImplementedError
  end
end

module Powerable
  def turn_on; end
  def turn_off; end
end

module VolumeControllable
  def volume_up; end
  def volume_down; end
end

class Television
  include Powerable
  include VolumeControllable
  # implementa todos os métodos
end

class Lightbulb
  include Powerable
  # implementa apenas métodos relacionados à Powerable
end

class OrderService
  def initialize
    @database = MySQLDatabase.new
  end
end

class OrderService
  def initialize(database)
    @database = database
  end
end

# Uso:
service = OrderService.new(MySQLDatabase.new)