grocery_list.rb

# Create a new list
# Add an item with a quantity to the list
# Remove an item from the list
# Update quantities for items in your list
# Print the list (Consider how to make it look nice!)

# DEFINE 'create_list' which takes no arguments:
#   create/return a new, empty, hash
# 
# DEFINE 'add', which takes three arguments, item (a string) and quantity (an integer), and list (a hash):
#   add item as a key and quantity as a value pair to the list
#
# DEFINE 'remove', which takes two arguments, an item (string), and a list (hash):
#   delete item key/value pair from hash
# 
# DEFINE 'update', which takes three arguments, an item (string), a new quantity (integer) and a list(hash):
#   reassign the key (item) with the value (the new quantity)
# 
# DEFINE print_list, which takes one argument, a hash
#   iterate over the hash, for each key/value pair DO the following:
#     print the key, then a hyphen surrounded by spaces, then the value, then a newline
# 


def create_list
  Hash.new
end

def add(item, quantity, list)
  if list[item]
    "#{item.upcase} is already on the list. It says you need #{list[item]}."
  else
    list[item] = quantity
  end
end

def remove(item, list)
  list.delete(item)
end

def update(item, quantity, list)
  list[item] = quantity
end

def print_list(list)
  if list.empty?
    puts "There's nothing here yet!"
  end
  list.each do |item, quantity|
    puts "#{item.upcase} - #{quantity}"
  end
  puts ""
end

def help
  "You can use any of the following commands on your list! 
When you make the command, fill in the bracketed arguments with specifics. 
ex: 'add 5 turnips' 
Remember to separate each word by (only) one space.

add [number] [item]
remove [item]
update [item] to [quantity]
help
quit

"
end

def run
  puts "Hello! Welcome to Grocery List v2.0"
  user_list = create_list
  puts "We have created a grocery list for you. Type 'help' to see a list of available commands."
  user_input = ""

  while user_input[0] != "quit"
    puts "What can I do for you?"
    user_input = gets.chomp.split(" ")
    puts ""
    case user_input[0]
    when 'add'
      add(user_input[2], user_input[1], user_list)
    when 'remove'
      remove(user_input[1], user_list)
    when 'update'
      update(user_input[1], user_input[3])
    when 'help'
      print help
    else
      puts "I'm sorry, I didn't understand you. Make sure you capslock isn't on."
    end
    puts "Got it! Here's what your list looks like now:"
    print_list(user_list)
  end
  puts "Goodbye! Come back soon!"
end

# either run the driver tests, OR the program, with the #run method

run

# ___________DRIVER CODE_____________

# new_list = create_list
# p new_list == {}
# add("broccoli", 7, new_list)
# p new_list == {"broccoli" => 7}
# remove("broccoli", new_list)
# p new_list == {}
# update("broccoli", 10, new_list)
# p new_list == {"broccoli" => 10} 
# add('spinach', 5, new_list)
# add('eggplant', 22, new_list)
# add('cherry tomatoes', 9000, new_list)
# print_list(new_list)