P5: OO Inheritance.rb

### PART 1 (write tests)

class Car
 @@WHEELS = 4
 def initialize(args)
   @color = args[:color]
   @wheels = @@WHEELS
 end
 def drive
   @status = :driving
 end
 def brake
   @status = :stopped    
 end
 def needs_gas?
   return [true,true,false].sample
 end
 
end
class Bus
 attr_reader :passengers
 def initialize(args)
   @color = args[:color]
   @wheels = args[:wheels]
   @num_seats = args[:num_seats]
   @fare = args[:fare]
   @passengers=[]
 end
 def drive
   return self.brake if stop_requested?
   @status = :driving
 end
 def admit_passenger(passenger,money)
   @passengers << passenger if money > @fare
 end
 def brake
   @status = :stopped
 end 
 def stop_requested?
   return [true,false].sample
 end
 def needs_gas?
   return [true,true,true,false].sample
 end
end
 
 
class Motorbike
 @@WHEELS = 2
 def initialize(args)
   @color = args[:color]
   @wheels = @@WHEELS
 end
 def drive
   @status = :driving
   @speed = :fast
 end
 
 def brake
   @status = :stopped 
 end
 def needs_gas?
   return [true,false,false,false].sample
 end 
 def weave_through_traffic
   @status = :driving_like_a_crazy_person
 end
end

car = Car.new({:color => "red"})
p car.drive == :driving
p car.brake == :stopped
p car.needs_gas? == true

bus = Bus.new({:color => "blue", :wheels => 6, :num_seats => 25, :fare => 3})
p bus.drive
p bus.admit_passenger("rachel", 5) == ["rachel"]
p bus.admit_passenger("caitlin", 4) == ["rachel", "caitlin"]
p bus.brake == :stopped
p bus.stop_requested?
p bus.needs_gas?

motorbike = Motorbike.new({:color => "black"})
p motorbike.drive == :fast
p motorbike.brake == :stopped
p motorbike.needs_gas?
p motorbike.weave_through_traffic == :driving_like_a_crazy_person



### PART 2 (refactoring with inheritance) and PART 3 (get creative)

class Vehicle
  attr_reader :status, :color, :speed
  def initialize(args)
    @color = args[:color]
    @status = :stopped
    @speed = 0
  end
  def drive
    @status = :driving
    accelerate
  end
  def brake
    @status = :stopped
    @speed = 0
  end
  def needs_gas?
    return [true, true, true, false].sample
  end
  def accelerate
    @speed += 10
  end
  def decelerate
    if @speed == 0
      "The bus cannot decelerate because it is already stopped!"
    else
      @speed -= 10
    end
  end
end

class Car < Vehicle
  attr_reader :wheels
  @@WHEELS = 4
  def initialize(args)
    super(args)
    @wheels = @@WHEELS
  end
end

class Bus < Vehicle
  attr_reader :fare, :num_seats, :passengers, :wheels
  def initialize(args)
    super(args)
    @wheels = args[:wheels]
    @fare = args[:fare]
    @num_seats = args[:num_seats]
    @passengers = []
  end
  def stop_requested?
    return [true, false].sample
  end
  def drive
    return self.brake if stop_requested?
    @status = :driving
    self.accelerate
  end
  def admit_passenger(passenger, money_paid)
    if money_paid < fare
      puts "You do not have enough money to get on the bus. Sorry!"
    elsif passengers.size >= num_seats
      puts "The bus is too full. We cannot admit another passenger. Sorry!"
    else
      passengers << passenger
      puts "Welcome aboard, #{passenger}!"
    end
  end
end


class Motorbike < Vehicle
  attr_reader :wheels
  @@WHEELS = 2
  def initialize(args)
    super(args)
    @wheels = @@WHEELS
  end
  def weave_through_traffic
    status = :driving_like_a_crazy_person
  end
end


motorbike = Motorbike.new({:color => "red"})
p motorbike.wheels == 2
p motorbike.speed == 0
p motorbike.drive == 10
p motorbike.speed == 10
p motorbike.drive == 20
p motorbike.weave_through_traffic == :driving_like_a_crazy_person
p motorbike.status == :driving
p motorbike.decelerate == 10
p motorbike.speed == 10
p motorbike.brake == 0
p motorbike.status == :stopped
p motorbike.needs_gas?


bus = Bus.new({:color => "blue", :wheels => 6, :num_seats => 25, :fare => 3})
p bus.wheels == 6
p bus.speed == 0
p bus.stop_requested?
bus.admit_passenger("rachel", 5) == "Welcome aboard, rachel!"
bus.admit_passenger("caitlin", 5) == "Welcome aboard, caitlin!"
p bus.admit_passenger("kylin", 2) == "You do not have enough money to get on the bus. Sorry!"
p bus.decelerate
p bus.brake == 0
p bus.status == :stopped
p bus.needs_gas?


car = Car.new({:color => "red"})
p car.wheels == 4
p car.speed == 0
p car.drive == 10
p car.speed == 10
p car.drive == 20
p car.drive == 30
p car.status == :driving
p car.decelerate == 20
p car.brake == 0
p car.status == :stopped
p car.needs_gas?