import java.util.Scanner;
import java.util.Random;

public class RPSGame
{
    public static void main(String[] args)
    {
        Scanner input = new Scanner(System.in);
        Random random = new Random();

        int computerPickInt, rock = 0, paper = 1, scissors = 2;
        String computerPick = "";
        Boolean quit = false;


        while(!quit) {
            System.out.println("Enter move (rock, paper, or scissors):");
            String userPick = input.nextLine();

            while (!userPick.equalsIgnoreCase("rock") && !userPick.equalsIgnoreCase("paper") && !userPick.equalsIgnoreCase("scissors")) {
                System.out.println("Illegal choice: " + userPick);
                System.out.print("Re-enter your play: ");
                userPick = input.nextLine();
            }

            computerPickInt = random.nextInt(3);

            switch (computerPickInt) {
                case 0:
                    computerPick = "rock";
                    break;
                case 1:
                    computerPick = "paper";
                    break;
                case 2:
                    computerPick = "scissors";
            }

            System.out.println("Computer chooses " + computerPick);

            if (userPick.equalsIgnoreCase(computerPick))
                System.out.println("It's a tie!");
            else if (userPick.equalsIgnoreCase("rock")) {
                if (computerPick.equals("paper"))
                    System.out.println("Paper covers rock! You lose.");
                else
                    System.out.println("Rock crushes scissors! You win!");
            } else if (userPick.equalsIgnoreCase("paper")) {
                if (computerPick.equals("rock"))
                    System.out.println("Paper covers rock! You win!");
                else
                    System.out.println("Scissors cut paper! You lose.");
            } else {
                if (computerPick.equals("rock"))
                    System.out.println("Rock crushes scissors! You lose.");
                else
                    System.out.println("Scissors cut paper! You win!");
            }
            System.out.print("Play again? Enter yes or no: ");
            String playAgain = input.nextLine();

            while(!playAgain.equalsIgnoreCase("yes") && !playAgain.equalsIgnoreCase("no")){
                System.out.print("Sorry, that is invalid.\nEnter yes or no: ");
                playAgain = input.nextLine();
            }
            if(playAgain.equalsIgnoreCase("no"))
                quit = true;
        }
    }
}