example adapter

ticket_adapter.rb

class Dev
  attr_accessor :level, :money, :tickets

  def initialize
    @level = (1..3).to_a.sample
    @money = 0
    @tickets = []
  end

  def take_ticket(ticket)
    @tickets << (ticket.dev = self)
  end

  def finish_ticket(ticket)
    ticket.finish
    @tickets.delete ticket
  end
end



class Ticket
  attr_accessor :difficulty, :dev

  def initialize(difficulty)
    @difficulty = difficulty
    @dev = nil
  end

  def finish
    @dev.money += calculate_money
  end

  def calculate_money
    (@difficulty * 50) * @dev.level
  end
end



class OldTicket
  attr_accessor :dev, :difficulty, :money

  def initialize
    @difficulty = (1..3).to_a.sample
    @money = 10
  end

  def done
    difficulty * money
  end
end



class TicketAdapter
  attr_accessor :dev

  def initialize(old_ticket, difficulty)
    @old_ticket = old_ticket
    @old_ticket.difficulty = difficulty
    @dev = nil
  end

  def finish
    @dev.money += @old_ticket.done
  end
end

dev = Dev.new
ticket = Ticket.new 5
dev.take_ticket ticket
dev.finish_ticket ticket
puts dev.money

some_old_ticket = OldTicket.new
old_ticket_adapted = TicketAdapter.new(some_old_ticket, 5)
dev.take_ticket old_ticket_adapted
dev.finish_ticket old_ticket_adapted
puts dev.money