shopping.rb

store = {
  apple: {
    price: 2,
    quantity: 40
  },
  pineapple: { price: 3, quantity: 80},
  strawberry: { price: 6, quantity: 60},
}


# greeting the user
puts "Welcome to Instacart"
puts "These are our items:"

# showing the store items
store.each  do |fruit, detail|
  # detail is a hash with the fruits details (price, quantity)
  puts "#{fruit}: #{detail[:price]}€ - #{detail[:quantity]} availabe"
end

# a hash with a default value of 0
# This will prevent the code from "throwing"
# an error in case we add up the quantities later
cart = Hash.new(0)
item = nil

while item != :quit
  puts "Which item do you want? (or quit to checkout):"
  item = gets.chomp.to_sym
  # check if the fruit exists
  # if store.keys?(item)
  if store[item].nil?
    if item != :quit
      puts "Fruit doesn't exist."
    end
  else
    puts "Hom many do you need?"
    quantity =  gets.chomp.to_i
    # we need to check if the store has that many items
    if quantity <= store[item][:quantity]
      # add the item to the cart with the quantity as a value
      cart[item] += quantity
      # Substracting the bought quantity from the store's quantity (availability)
      store[item][:quantity] -= quantity
    else
      puts "Ooops! We don't have that many #{item}"
      puts "we only have #{store[item][:quantity]}"
    end
  end
end

puts "-------------BILL-------------"
total = 0
cart.each do |fruit, quantity|
  fruit_price = quantity * store[fruit][:price]
  puts "#{fruit}: #{quantity} X #{store[fruit][:price]}€ = #{fruit_price}€"
  total += fruit_price
end
puts "TOTAL: #{total}€"
puts "-----------------------------"