rock_paper_scissors

rock_paper_scissors.rb

def round
  # Get user's user_selection
  puts 'Please type your selection "rock" [r], "paper" [p] or "scissors" [s]. You can always quit the game by typing "quit" [q].'
  user_input = gets.chomp.downcase

  # Create a list with the selections of the game (except the quit option)
  options = ["rock", "paper", "scissors", "r", "p", "s"]

  # Check if the user has selected to quit or if he has typed an invalid selection
  if ["quit", "q"].include? user_input
    puts "Happy to play with you! See you next time! Bye!!"
    return false
  elsif ! options.include? user_input
    puts 'You typed an invalid selection.'
    return true
  end

  # Get match of user's selection to the index of the options array
  user_selection = options.index(user_input)
  user_selection -= 3 if user_selection > 2
  # Get a random computer's selection.
  computer_selection = rand(3)

  # Get the difference user_selection minus computer_selection
  diff = user_selection - computer_selection

  # Get the result of the game:
  # 0 -> tie, -2, 1 -> win for the user, -1, 2 loss for the user
  case diff
  when 0
    puts "You both selected #{options[computer_selection]}. There is a tie."
  when -2, 1
    puts "Congrats!! You won! The computer selected #{options[computer_selection]}."
  when -1, 2
      puts "Sorry but you lost... The computer selected #{options[computer_selection]}."
  end

  # Ask the user to continue playing
  puts 'Would you like to play another round? Please type "yes" [y] or "no" [n]:'
  newround = true
  while newround
    user_selection = gets.chomp.downcase
    case user_selection
    when "yes", "y"
      return true
    when "no", "n"
      puts "Happy to play with you! See you next time! Bye!!"
      return false
    else
      puts 'You typed an invalid selection. Please type in "yes" if you want to '\
        'continue playing or "no" if you want to leave the game:'
    end
  end
  
end

# Welcome message and start the game
puts 'Hello! Ready to play "Rock, Paper, Scissors"?'
play = true
while play
  play = round
end