Robots.rb

robots.rb

# frozen_string_literal: true

# Robot name
# When robots come off the factory floor, they have no name.
#
# The first time you boot them up, a random name is generated in the format of two uppercase letters followed by three digits, such as RX837 or BC811.
#
# Every once in a while we need to reset a robot to its factory settings, which means that their name gets wiped. The next time you ask, it will respond with a new random name.
#
# The names must be random: they should not follow a predictable sequence.
# Random names means a risk of collisions. Your solution must ensure that every existing robot has a unique name.

module Name
  LETTERS = ('A'..'Z').to_a
  NUMBERS = (0..9).to_a

  def generate
    2.times.map { LETTERS.sample }.join + 3.times.map { NUMBERS.sample.to_s }.join
  end
end

class RobotManager
  include Name
  attr_reader :robots

  def initialize
    @robots = []
  end

  def boot_all
    @robots.each(&:boot)
  end

  def reset_all
    @robots.each(&:reset)
  end

  def create_robots(number)
    number.times do
      @robots << Robot.new { generate_name }
    end
    @robots
  end

  def create_robot
    @robots << Robot.new { generate_name }
    @robots.last
  end

  def generate_name
    excluded_names = @robots.map do |robot|
      robot.name(just_checking: true)
    end
    loop do
      name = generate
      return name unless excluded_names.include?(name)
    end
  end
end

class Robot
  attr_accessor :status, :has_been_booted

  DEFAULT_NAME = 'Unnamed'

  def initialize(&block)
    @status = :off
    @has_been_booted = false
    @name_generator = block
    @name = DEFAULT_NAME
  end

  def name(just_checking: false)
    if !@has_been_booted
      @name
    elsif @has_been_booted && @name == DEFAULT_NAME && !just_checking
      # if this is true then we need a new name
      @name = @name_generator.call
    else
      @name
    end
  end

  def boot
    @has_been_booted = true
    @status = :on
  end

  def shutdown
    @status = :off
  end

  def reset
    @name = DEFAULT_NAME
    @has_been_booted = false
    @status = :off
  end
end

# Create 10 robots which should have default names and status: off
puts 'Creating 10 robots...'
manager = RobotManager.new
manager.create_robots(10)

# Select the first robot
bot1 = manager.robots.first
puts "Robot 1 name is: #{bot1.name} and status: #{bot1.status}"

# We boot it up for the first time
puts 'Booting up robot 1...'
bot1.boot

# We ask the robot name again
puts "Robot 1 name is: #{bot1.name} and status: #{bot1.status}"

# Now lets boot all the robots and see who has names
puts 'Booting all robots...'
manager.boot_all
manager.robots.each_with_index do |robot, index|
  puts "#{index + 1}. Robot name is: #{robot.name} and status: #{robot.status}"
end

# Now lets reset all the robots and see who has names
puts 'Resetting all robots...'
manager.reset_all
manager.robots.each_with_index do |robot, index|
  puts "#{index + 1}. Robot name is: #{robot.name} and status: #{robot.status}"
end