loop do
  choices = ["rock", "paper", "scissors"]
  computer_choice = choices[rand(choices.length)]
  puts "Welcome to the game! Please choose either rock, paper or scissors:"
  user_choice = gets.chomp.downcase

  while !(user_choice == "rock" || user_choice == "paper" || user_choice == "scissors")
    puts "Invalid choice - please choose again."
    user_choice = gets.chomp.downcase
  end
  if  (user_choice == "rock" || user_choice == "paper" || user_choice == "scissors")
    if (user_choice == computer_choice)
      puts "Answers match - you've tied!"
    elsif (user_choice == "rock" && computer_choice == "paper")
      puts "Computer chose #{computer_choice} : you lose..."
    elsif (user_choice == "rock" && computer_choice == "scissors")
      puts "Computer chose #{computer_choice} : you win!"
    elsif (user_choice == "paper" && computer_choice == "scissors")
      puts "Computer chose #{computer_choice} : you lose..."
    elsif (user_choice == "paper" && computer_choice == "rock")
      puts "Computer chose #{computer_choice} : you win!"
    elsif (user_choice == "scissors" && computer_choice == "rock")
      puts "Computer chose #{computer_choice} : you lose..."
    elsif (user_choice == "scissors" && computer_choice == "paper")
      puts "Computer chose #{computer_choice} : you win!"
    end
    puts "Would you like to play again? (Y/N)"
    user_answer = gets.chomp.downcase
    while !(user_answer == "y" || user_answer == "n")
      puts "Invalid choice - please choose again."
      user_answer = gets.chomp.downcase
    end
    break if user_answer == "n"
  end
end