Moving from Procedural to OOP Programming

old_way.rb

# Brewery related Functions

def create_beer(brewery, name, style, abv)
  beer = {name: name, style: style, abv: abv, quantity: 0}
  brewery[:beers] << beer
end

def print_brewery(brewery)
  puts "\n"
  puts "#{brewery[:name]}"
  puts "Address: #{brewery[:address]}, #{brewery[:city]}"
  puts "Beer List"
  brewery[:beers].each do |beer|
    puts "\t#{beer[:name]} | #{beer[:style]} | #{beer[:quantity]}"
  end
end

def brew_beer(brewery, beer_name, quantity)
  beer = brewery[:beers].find { |x| x[:name] == beer_name }
  beer[:quantity] += quantity
end


def sell_beer(brewery, beer_name, quantity)
  beer = brewery[:beers].find { |x| x[:name] == beer_name }
  beer[:quantity] -= quantity
end

# Run / Test the Code


puts "Create the Brewery"
brewery = {
  name: 'Sawdust City Brewing',
  address: '345 Main St',
  city: 'Gravenhurst',
  beers: []
}
print_brewery(brewery)

puts "Add a beer to the brewery"
create_beer(brewery, 'Lone Pine', 'IPA', 5.5)
print_brewery(brewery)

puts "Brew some of that beer"
brew_beer(brewery, 'Lone Pine', 10)
print_brewery(brewery)

puts "Sell some of that beer"
sell_beer(brewery, 'Lone Pine', 5)
print_brewery(brewery)

oop_way.rb

class Beer
  attr_reader :name

  def initialize(name, style, abv)
    @name = name
    @style = style
    @abv = abv
  end

  def beer_description
    "#{@name} | #{@style}"
  end
end

class SKU
  attr_accessor :quantity

  def initialize(beer, quantity)
    @beer = beer
    @quantity = quantity
  end

  def print_details
    "#{@beer.beer_description} | #{@quantity}"
  end

  def beer_name
    @beer.name
  end

  #delegate :beer_name, @beer
end

class Brewery
  def initialize(name, address, city)
    @name = name
    @address = address
    @city = city
    @beers = []
  end

  def add_beer(beer)
    @beers << SKU.new(beer, 0)
  end

  def brew_beer(beer_name, amount)
    beer = find_beer(beer_name)
    beer.quantity += amount
  end

  def sell_beer(beer_name, amount)
    beer = find_beer(beer_name)
    beer.quantity -= amount
  end

  def print_details
    puts "\n"
    puts "#{@name}"
    puts "Address: #{@address}, #{@city}"
    puts "Beer List"
    @beers.each do |beer|
      puts "\t #{beer.print_details}"
    end
  end

  private

  def find_beer(beer_name)
    @beers.find { |x| x.beer_name == beer_name }
  end
end


# Run / Test the Code

puts "Create the Brewery"
brewery = Brewery.new(
  "Sawdust City Brewing",
  "345 Main St",
  "Gravenhurst"
)
brewery.print_details()

puts "Add a beer to the brewery"
beer = Beer.new('Lone Pine', "IPA", 5.5)
brewery.add_beer(beer)
brewery.print_details()

puts "Brew some of that beer"
brewery.brew_beer('Lone Pine', 100)
brewery.print_details()

puts "Sell some of that Beer"
brewery.sell_beer('Lone Pine', 50)
brewery.print_details()