my_car.rb

#!/usr/bin/env ruby
# frozen_string_literal: true

# From https://launchschool.com/books/oo_ruby/read/classes_and_objects_part1#exercises
# 1. Create a class called MyCar. When you initialize a new instance or object of the class, allow the user to define
# some instance variables that tell us the year, color, and model of the car. Create an instance variable that is set
# to 0 during instantiation of the object to track the current speed of the car as well. Create instance methods that
# allow the car to speed up, brake, and shut the car off.

# 2. Add an accessor method to your MyCar class to change and view the color of your car. Then add an accessor method
# that allows you to view, but not modify, the year of your car.

# 3. You want to create a nice interface that allows you to accurately describe the action you want your program to
# perform. Create a method called spray_paint that can be called on an object and will modify the color of the car.

# From https://launchschool.com/books/oo_ruby/read/classes_and_objects_part2#exercises#
# 1. Add a class method to your MyCar class that calculates the gas mileage (i.e. miles per gallon) of any car.

# 2. Override the to_s method to create a user friendly print out of your object.

# From https://launchschool.com/books/oo_ruby/read/inheritance#exercises
# 1. Create a superclass called Vehicle for your MyCar class to inherit from and move the behavior that isn't
# specific to the MyCar class to the superclass. Create a constant in your MyCar class that stores information
# about the vehicle that makes it different from other types of Vehicles.
#
# Then create a new class called MyTruck that inherits from your superclass that also has a constant defined that
# separates it from the MyCar class in some way.

# 2. Add a class variable to your superclass that can keep track of the number of objects created that inherit from
# the superclass. Create a method to print out the value of this class variable as well.
class Vehicle
  @@vehicle_count = 0

  def self.vehicle_count
    @@vehicle_count ||= 0
  end

  def self.gas_mileage(gallons, miles)
    gm = miles.to_f / gallons
    puts "#{gm} miles per gallon of gas"
    gm
  end

  attr_reader :model, :year, :speed
  attr_accessor :color

  def initialize(model, year, color)
    @speed = 0
    @model = model
    @year = year
    @color = color
    @@vehicle_count += 1
  end

  def current_speed
    puts "Your current speed is #{@current_speed} mph."
  end

  def speed_up(incremental_speed)
    puts "You are accelerating by #{incremental_speed} mph."
    @speed += incremental_speed
  end

  def brake(decremental_speed)
    puts "You are decelerating by #{decremental_speed} mph."
    @speed -= decremental_speed
  end

  def shut_off
    puts 'You are stopped'
    @speed = 0
  end

  def spray_paint(color)
    @color = color
    puts "Your new #{color} paint job looks great!"
  end
end

# For Truck
module Towable
  def can_tow?(pound)
    pound < 2000
  end
end

class MyCar < Vehicle
  NUMBER_OF_WHEELS = 4

  def to_s
    "My car is #{@model}/#{@year}/#{@color}"
  end

end

class MyTruck < Vehicle
  NUMBER_OF_WHEELS = 18

  include Towable

  def to_s
    "My Truck is #{@model}/#{@year}/#{@color}"
  end

end

# MyCarTest is a class designed to performed test over MyCar
class MyCarTest
  attr_reader :id, :passed, :failed

  def initialize
    @id = 0
    @passed = 0
    @failed = 0
  end

  def verify_speed(car, action, param, expected)
    result = (param ? car.send(action, param) : car.send(action)) == expected
    update_counters(result)
    puts "Test #{@id}: #{result ? 'PASS' : 'FAIL'} #{car} -> #{action}(#{param}) == #{expected}"
  end

  def verify_color(car, expected)
    result = car.color == expected
    update_counters(result)
    puts "Test #{id}: #{result ? 'PASS' : 'FAIL'} #{car} is #{expected}"
  end

  def verify_instance_counter(expected)
    result = Vehicle.vehicle_count == expected
    update_counters(result)
    puts "Test #{id}: #{result ? 'PASS' : 'FAIL'} instance count is #{expected}"
  end

  def to_s
    "\nTest Summary: #{@passed}/#{@id} passed, #{@failed}/#{@id} failed"
  end

  def verify_gas_mileage(gallons, miles, expected)
    result = MyCar.gas_mileage(gallons, miles)
    update_counters(result == expected)
    puts "Test #{id}: #{result == expected ? 'PASS' : 'FAIL'} Gas Mileage(#{gallons}, #{miles}) is #{expected} miles per gallon"
  end

  private

  def update_counters(test_status)
    @id += 1
    if test_status
      @passed += 1
    else
      @failed += 1
    end
  end
end

f150 = MyCar.new('F150', '2025', 'yellow')
test = MyCarTest.new

test.verify_instance_counter(1)
test.verify_speed(f150, 'shut_off', nil, 0)
test.verify_speed(f150, 'speed_up', 10, 10)
test.verify_speed(f150, 'speed_up', 10, 20)
test.verify_speed(f150, 'speed_up', 100, 120)
test.verify_speed(f150, 'brake', 50, 70)
test.verify_color(f150, 'yellow')
f150.color = 'blue'
test.verify_color(f150, 'blue')
f150.spray_paint('red')
test.verify_color(f150, 'red')

test.verify_gas_mileage(8, 100, 100.0 / 8.0)
puts test # print summary