GeminiRPSGame.java

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

public class GeminiRPSGame {

    // --- Enum for Moves ---
    enum Move {
        ROCK, PAPER, SCISSORS, NONE
    }

    // --- Global Variables ---
    static int playerScore = 0;
    static int computerScore = 0;

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        // --- 1. Distinct Gemini Intro (Asterisk Box) ---
        System.out.println("*************************************************");
        System.out.println("* *");
        System.out.println("* This is created by Gemini 3          *");
        System.out.println("* Multithreaded Rock, Paper, Scissors       *");
        System.out.println("* *");
        System.out.println("*************************************************");
        System.out.println();

        // --- 2. Explain the Rules Clearly ---
        System.out.println("WELCOME, CHALLENGER!");
        System.out.println("Here are the rules of engagement:");
        System.out.println("1. Rock beats Scissors.");
        System.out.println("2. Scissors beats Paper.");
        System.out.println("3. Paper beats Rock.");
        System.out.println();
        System.out.println("HOW TO PLAY:");
        System.out.println("When prompted, type one of the following letters and press ENTER:");
        System.out.println(" - Type 'R' for Rock");
        System.out.println(" - Type 'P' for Paper");
        System.out.println(" - Type 'S' for Scissors");
        System.out.println(" - Type 'Q' to Quit the game");
        System.out.println("*************************************************");
        System.out.println();

        // --- 3. Ask for User Name ---
        System.out.print("Please enter your name to begin: ");
        String playerName = scanner.nextLine();
        
        // Handle empty name
        if (playerName == null || playerName.trim().isEmpty()) {
            playerName = "Player 1";
        }
        
        System.out.println("\nReady, " + playerName + "? Let's start!");

        boolean keepPlaying = true;

        // --- 4. Game Loop ---
        while (keepPlaying) {
            System.out.println("\n-------------------------------------------------");
            System.out.println("CURRENT SCORE -> " + playerName + ": " + playerScore + " | Computer: " + computerScore);
            System.out.print("Your move (R/P/S) or Q to quit: ");
            
            String input = scanner.nextLine().toUpperCase().trim();
            
            // Handle Quit
            if (input.equals("Q")) {
                keepPlaying = false;
                System.out.println("Quitting game...");
                continue;
            }

            Move playerMove = parseInput(input);

            // Handle Invalid Input
            if (playerMove == Move.NONE) {
                System.out.println("!!! Invalid input. Please type R, P, or S only.");
                continue;
            }

            // --- 5. Multithreading Implementation ---
            // We create a separate thread for the Computer to 'think'
            ComputerAI computerThread = new ComputerAI();
            computerThread.start();

            // While the thread works, we show a loading animation on the main thread
            try {
                System.out.print("Computer is thinking");
                for(int i=0; i<3; i++) {
                    Thread.sleep(400); // Main thread pauses purely for effect
                    System.out.print(".");
                }
                System.out.println();
                
                // CRITICAL: We wait for the computer thread to finish before moving on
                computerThread.join(); 
                
            } catch (InterruptedException e) {
                System.out.println("Game interrupted!");
            }

            // Retrieve the move from the thread
            Move computerMove = computerThread.getMove();

            // Determine and display the winner
            determineWinner(playerName, playerMove, computerMove);
        }

        // --- 6. End Game Summary ---
        System.out.println("\n*************************************************");
        System.out.println("* FINAL RESULTS                *");
        System.out.println("*************************************************");
        System.out.printf("* %-15s: %d                             *\n", playerName, playerScore);
        System.out.printf("* %-15s: %d                             *\n", "Computer", computerScore);
        System.out.println("*************************************************");
        
        if (playerScore > computerScore) {
            System.out.println("* CONGRATULATIONS! YOU WON!              *");
        } else if (computerScore > playerScore) {
            System.out.println("* GAME OVER. COMPUTER WINS.           *");
        } else {
            System.out.println("* IT'S A DRAW!                     *");
        }
        System.out.println("*************************************************");
        
        scanner.close();
    }

    // --- Helper Method to Parse Input ---
    private static Move parseInput(String input) {
        // We only check the first character just in case user types "Rock" instead of "R"
        if (input.length() < 1) return Move.NONE;
        
        char firstChar = input.charAt(0);
        switch (firstChar) {
            case 'R': return Move.ROCK;
            case 'P': return Move.PAPER;
            case 'S': return Move.SCISSORS;
            default: return Move.NONE;
        }
    }

    // --- Helper Method to Determine Winner ---
    private static void determineWinner(String name, Move pMove, Move cMove) {
        System.out.println("\n> " + name + " chose: " + pMove);
        System.out.println("> Computer chose: " + cMove);
        System.out.println("-------------------------------------------------");

        if (pMove == cMove) {
            System.out.println("RESULT: It's a Tie!");
        } else if (
            (pMove == Move.ROCK && cMove == Move.SCISSORS) ||
            (pMove == Move.PAPER && cMove == Move.ROCK) ||
            (pMove == Move.SCISSORS && cMove == Move.PAPER)
        ) {
            System.out.println("RESULT: " + getWinningPhrase(pMove) + " You Win this round!");
            playerScore++;
        } else {
            System.out.println("RESULT: " + getWinningPhrase(cMove) + " Computer Wins this round!");
            computerScore++;
        }
    }

    // --- Helper Method for Flavor Text ---
    private static String getWinningPhrase(Move move) {
        switch (move) {
            case ROCK: return "Rock crushes Scissors!";
            case PAPER: return "Paper covers Rock!";
            case SCISSORS: return "Scissors cuts Paper!";
            default: return "";
        }
    }

    // --- The Computer Thread Class ---
    // This runs the AI logic on a separate execution thread
    static class ComputerAI extends Thread {
        private Move selectedMove;
        private Random random = new Random();

        @Override
        public void run() {
            // The AI logic happens here, completely separate from user input handling
            // We simulate a 'thinking' delay and then pick a random move
            try {
                Thread.sleep(500); // Simulate processing time
                int pick = random.nextInt(3);
                selectedMove = Move.values()[pick];
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        public Move getMove() {
            return selectedMove;
        }
    }
}