Car Class

car.rb

# color, brand, speed

# Class names are in UpperCamelCase
# Open a class statement
class Car
  attr_reader :brand, :license_plate # Creates GETTERS
  # attr_writer :color # Creates SETTERS
  attr_accessor :color # Creates GETTERS and SETTERS

  # This is the constructor
  # it will be called in Car.new
  def initialize(brand, color = "blue")
    # Define instance variables (DATA/STATE):
    @brand = brand
    @color = color
    @speed = 0
    @engine_started = false
    @license_plate = create_registration

    puts "Created a car instance 🚗 with license plate number #{@license_plate}"
  end

  # Getter / Reads internal data
  # def color
  #   @color
  # end

  # Setter / Writes internal data
  # def color=(color)
  #   @color = color
  # end


  # PUBLIC INTERFACE (BEHAVIOR)
  def engine_started?
    @engine_started
  end

  def start_engine
    start_fuel_pump
    fire_spark_plug
    @engine_started = true
  end

  def accelerate
    return unless engine_started?

    @speed += 50

    if @speed <= 150
      puts "VRUMMMMM.... #{'🏎' * (@speed / 50)}"
    else
      @engine_started = false
      puts "You fool! You crashed! 🚑"
    end
  end

  def brake
    return if @speed.zero?

    @speed -= 50
    puts "Braking..."
  end

  private

  def create_registration
    digits = (0..9).to_a.sample(4).join
    letters = ("A".."Z").to_a.sample(3).join
    # [digits, letters].join("-")
    "#{digits}-#{letters}"
  end

  def start_fuel_pump
    puts "Pumping fuel into the engine... ⛽️⛽️⛽️"
  end

  def fire_spark_plug
    puts "Combustion explosion 💥"
  end
end

interface.rb

require_relative "car"
require "byebug"

puts "==================CARS=================="
my_car = Car.new("Honda")
your_car = Car.new("Seat", "green")

puts "My car is a #{my_car.color} #{my_car.brand}"
puts "Your car is a #{your_car.color} #{your_car.brand}"

puts "Let's paint my car!"
my_car.color = "red"
puts "Now, my car is #{my_car.color}"

your_car.start_engine # public interface

# It's not possible to call private methods
# your_car.start_fuel_pump

if your_car.engine_started?
  puts "Your car is running..."
else
  puts "Your car is parked"
end

puts "==================FERRARI=================="

ferrari = Car.new("Ferrari", "red")

ferrari.start_engine
ferrari.accelerate
ferrari.brake
6.times { ferrari.accelerate }