/**
 * ================================================================================
 * SiPro SocketArena™ - Question 2: TCP Even/Odd Game Client
 * ================================================================================
 * COURSE       : Distributed Computing & Systems Programming
 * ASSIGNMENT   : Q2 - TCP Client Application for Networked Even/Odd Game
 * LANGUAGE     : Java (SE 11+)
 * OBJECTIVE    : Connect to the concurrent Even/Odd TCP server, send the PLAY registration,
 *                prompt candidate for a chosen number (1-10) and parity guess ("EVEN" or "ODD"),
 *                transmit the GUESS command frame, and parse the server RESULT frame.
 * PROTOCOL     : RFC-SIPRO-EVENODD (ASCII Line-Delimited TCP Protocol)
 *
 * STUDENT INSTRUCTIONS:
 * Complete all 8 fill-in-the-blank sections marked with:
 *     // >>> FILL IN THE BLANK [X]: ... <<<
 *
 * COMPILATION & EXECUTION:
 *   javac EvenOddClient.java
 *   java EvenOddClient [YourName]
 * ================================================================================
 */

import java.io.*;
import java.net.*;
import java.util.Scanner;

public class EvenOddClient {

    public static final String DEFAULT_HOST = "127.0.0.1";
    public static final int PORT = 9098;

    public static void runClient(String host, int port, String playerName) {
        Socket socket = null;
        Scanner scanner = new Scanner(System.in);

        try {
            // >>> FILL IN THE BLANK [1]: Create a TCP stream client socket <<<
            // socket = new Socket();
            socket = null; // REPLACE THIS LINE

            // >>> FILL IN THE BLANK [2]: Connect client socket to the server (host, port) <<<
            // socket.connect(new InetSocketAddress(host, port));
            // System.out.println("[CONNECTED] Established TCP connection to " + host + ":" + port);
            // REPLACE THIS BLOCK

            if (socket == null) {
                System.out.println("[SIMULATION] Socket not initialized. Please complete Blank 1 & 2.");
                return;
            }

            // >>> FILL IN THE BLANK [3]: Initialize BufferedReader stream from socket.getInputStream() <<<
            // BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            BufferedReader in = null; // REPLACE THIS LINE

            // >>> FILL IN THE BLANK [4]: Initialize PrintWriter stream with autoflush enabled <<<
            // PrintWriter out = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()), true);
            PrintWriter out = null; // REPLACE THIS LINE

            if (in == null || out == null) {
                System.out.println("[SIMULATION] Stream readers/writers not initialized. Complete Blank 3 & 4.");
                return;
            }

            // Read server welcome banner
            String banner = in.readLine();
            System.out.println("[SERVER READY]: " + banner);

            // >>> FILL IN THE BLANK [5]: Send the initial registration message ("PLAY <playerName>") <<<
            // out.println("PLAY " + playerName);
            // REPLACE THIS LINE

            String welcomeMsg = in.readLine();
            System.out.println("[SERVER]: " + welcomeMsg);

            boolean playAgain = true;
            while (playAgain) {
                System.out.println("\n-------------------------------------------------------");
                System.out.println("  ROUND SELECTION: Pick a number and make your guess!");
                System.out.println("-------------------------------------------------------");

                int chosenNumber = 0;
                while (chosenNumber < 1 || chosenNumber > 10) {
                    System.out.print("Enter your chosen number (1 - 10): ");
                    try {
                        String input = scanner.nextLine().trim();
                        if (input.equalsIgnoreCase("quit")) {
                            out.println("QUIT");
                            return;
                        }
                        chosenNumber = Integer.parseInt(input);
                        if (chosenNumber < 1 || chosenNumber > 10) {
                            System.out.println("Number must be between 1 and 10.");
                        }
                    } catch (NumberFormatException e) {
                        System.out.println("Invalid input. Please enter an integer.");
                    }
                }

                String guessParity = "";
                while (!guessParity.equals("EVEN") && !guessParity.equals("ODD")) {
                    System.out.print("Guess whether total sum will be EVEN or ODD: ");
                    String input = scanner.nextLine().trim().toUpperCase();
                    if (input.equalsIgnoreCase("quit")) {
                        out.println("QUIT");
                        return;
                    }
                    if (input.equals("EVEN") || input.equals("ODD")) {
                        guessParity = input;
                    } else {
                        System.out.println("Invalid guess. Type 'EVEN' or 'ODD'.");
                    }
                }

                // >>> FILL IN THE BLANK [6]: Format and transmit the GUESS command ("GUESS <number> <EVEN|ODD>") <<<
                // String command = "GUESS " + chosenNumber + " " + guessParity;
                // out.println(command);
                // System.out.println("[SENT WIRE FRAME]: " + command);
                // REPLACE THIS BLOCK

                // >>> FILL IN THE BLANK [7]: Read the incoming RESULT response frame from the server <<<
                // String resultLine = in.readLine();
                String resultLine = null; // REPLACE THIS LINE

                if (resultLine == null) {
                    System.out.println("\n[DISCONNECTED] Server closed the connection.");
                    break;
                }

                System.out.println("[SERVER RESPONSE]: " + resultLine);

                // Parse outcome frame: RESULT <WIN|LOSS> <clientNum> <serverNum> <sum> <actualParity> <msg>
                String[] parts = resultLine.split("\\s+");
                if (parts.length >= 6 && parts[0].equalsIgnoreCase("RESULT")) {
                    String outcome = parts[1];
                    String cNum = parts[2];
                    String sNum = parts[3];
                    String totalSum = parts[4];
                    String actualParity = parts[5];

                    StringBuilder message = new StringBuilder();
                    for (int i = 6; i < parts.length; i++) {
                        message.append(parts[i]).append(" ");
                    }

                    System.out.println("\n*******************************************************");
                    if ("WIN".equalsIgnoreCase(outcome)) {
                        System.out.println("🏆 RESULT: VICTORY!");
                    } else {
                        System.out.println("💀 RESULT: DEFEAT!");
                    }
                    System.out.println("Your Number   : " + cNum);
                    System.out.println("Server Number : " + sNum);
                    System.out.println("Total Sum     : " + totalSum + " (" + actualParity + ")");
                    System.out.println("Your Guess    : " + guessParity);
                    System.out.println("Details       : " + message);
                    System.out.println("*******************************************************");
                }

                System.out.print("\nPlay another round? (y/n): ");
                String again = scanner.nextLine().trim();
                if (!again.equalsIgnoreCase("y") && !again.equalsIgnoreCase("yes")) {
                    out.println("QUIT");
                    playAgain = false;
                }
            }

            String bye = in.readLine();
            if (bye != null) System.out.println("[SERVER]: " + bye);

        } catch (ConnectException e) {
            System.err.println("[ERROR] Could not connect to Even/Odd Server at " + host + ":" + port);
            System.err.println("Ensure EvenOddServer is running: java EvenOddServer");
        } catch (IOException e) {
            System.err.println("[CLIENT EXCEPTION] " + e.getMessage());
        } finally {
            // >>> FILL IN THE BLANK [8]: Gracefully close the client socket <<<
            // if (socket != null && !socket.isClosed()) {
            //     try { socket.close(); } catch (IOException ignored) {}
            // }
            System.out.println("[CLIENT] Socket closed. Session terminated.");
        }
    }

    public static void main(String[] args) {
        String name = (args.length > 0) ? args[0] : "Player_" + (int)(Math.random() * 1000);
        runClient(DEFAULT_HOST, PORT, name);
    }
}