/**
 * ================================================================================
 * SiPro SocketArena™ - Assignment: Networked Tic-Tac-Toe TCP Client
 * ================================================================================
 * COURSE       : Distributed Computing & Systems Programming
 * ASSIGNMENT   : Networked Two-Player Tic-Tac-Toe Client Application
 * LANGUAGE     : Java (SE 11+)
 * OBJECTIVE    : Connect to the concurrent TCP game server, send the JOIN command,
 *                parse incoming board states and turn directives, prompt the user
 *                for grid coordinates, and transmit MOVE commands.
 * PROTOCOL     : RFC-SIPRO-TTT (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 TicTacToeClient.java
 *   java TicTacToeClient [YourName]
 * ================================================================================
 */

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

public class TicTacToeClient {

    public static final String DEFAULT_HOST = "127.0.0.1";
    public static final int PORT = 9099;

    /**
     * Renders a 9-character string as a standard 3x3 Tic-Tac-Toe grid.
     */
    public static void renderBoard(String boardStr) {
        if (boardStr == null || boardStr.length() != 9) {
            return;
        }
        char[] b = new char[9];
        for (int i = 0; i < 9; i++) {
            char c = boardStr.charAt(i);
            b[i] = (c != ' ') ? c : '.';
        }

        System.out.println("\n   0   1   2  (Cols)");
        System.out.println("0  " + b[0] + " | " + b[1] + " | " + b[2]);
        System.out.println("  ---+---+---");
        System.out.println("1  " + b[3] + " | " + b[4] + " | " + b[5]);
        System.out.println("  ---+---+---");
        System.out.println("2  " + b[6] + " | " + b[7] + " | " + b[8]);
        System.out.println();
    }

    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;
            }

            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            PrintWriter out = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()), true);

            // >>> FILL IN THE BLANK [3]: Frame and send the initial JOIN message ("JOIN <playerName>") <<<
            // out.println("JOIN " + playerName);
            // REPLACE THIS LINE

            System.out.println("[REGISTERED] Sent join request as '" + playerName + "'. Waiting for matchmaking...");

            String mySymbol = null;
            String opponentName = null;

            while (true) {
                // >>> FILL IN THE BLANK [4]: Read incoming newline-delimited line from server stream <<<
                // String line = in.readLine();
                String line = null; // REPLACE THIS LINE

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

                line = line.trim();
                if (line.isEmpty()) continue;

                String[] tokens = line.split("\\s+");
                String msgType = tokens[0].toUpperCase();

                // >>> FILL IN THE BLANK [5]: Handle server protocol directives <<<
                switch (msgType) {
                    case "WAIT":
                        System.out.println("[MATCHMAKING] " + (line.length() > 5 ? line.substring(5) : "Waiting..."));
                        break;

                    case "START":
                        // Syntax: START <X|O> <opponent_name>
                        mySymbol = tokens[1];
                        opponentName = tokens.length > 2 ? tokens[2] : "Opponent";
                        System.out.println("\n=======================================================");
                        System.out.println("  GAME STARTED! You are playing as: [" + mySymbol + "]");
                        System.out.println("  Your Opponent: " + opponentName);
                        System.out.println("=======================================================");
                        break;

                    case "BOARD":
                        // Syntax: BOARD <9-char-string>
                        if (tokens.length > 1) {
                            // >>> FILL IN THE BLANK [7]: Call renderBoard() with board string (tokens[1]) <<<
                            // renderBoard(tokens[1]);
                        }
                        break;

                    case "YOUR_TURN":
                        System.out.println("👉 YOUR TURN (" + mySymbol + ")! Enter row and col coordinates (0, 1, or 2):");
                        boolean validInput = false;
                        while (!validInput) {
                            System.out.print("Enter 'row col' (or 'quit'): ");
                            String userIn = scanner.nextLine().trim();
                            if (userIn.equalsIgnoreCase("quit")) {
                                out.println("QUIT");
                                return;
                            }
                            String[] parts = userIn.split("\\s+");
                            if (parts.length == 2) {
                                try {
                                    int r = Integer.parseInt(parts[0]);
                                    int c = Integer.parseInt(parts[1]);
                                    if (r >= 0 && r <= 2 && c >= 0 && c <= 2) {
                                        // >>> FILL IN THE BLANK [6]: Format and transmit MOVE command ("MOVE <r> <c>") <<<
                                        // out.println("MOVE " + r + " " + c);
                                        validInput = true;
                                    } else {
                                        System.out.println("Row and column indices must be 0, 1, or 2.");
                                    }
                                } catch (NumberFormatException e) {
                                    System.out.println("Coordinates must be numeric integers (e.g. '1 1').");
                                }
                            } else {
                                System.out.println("Invalid format. Enter two numbers separated by a space (e.g. '0 2').");
                            }
                        }
                        break;

                    case "OPPONENT_TURN":
                        System.out.println("⏳ Waiting for opponent (" + opponentName + ") to make a move...");
                        break;

                    case "INVALID_MOVE":
                        String reason = line.length() > 13 ? line.substring(13) : "Invalid move attempt.";
                        System.out.println("⚠️ [INVALID MOVE]: " + reason);
                        break;

                    case "MATCH_OVER":
                        // Syntax: MATCH_OVER <VICTORY|DEFEAT|DRAW|OPPONENT_QUIT> <explanation...>
                        String status = tokens.length > 1 ? tokens[1] : "COMPLETED";
                        StringBuilder explanation = new StringBuilder();
                        for (int i = 2; i < tokens.length; i++) {
                            explanation.append(tokens[i]).append(" ");
                        }

                        System.out.println("\n*******************************************************");
                        if ("VICTORY".equals(status)) {
                            System.out.println("🏆 VICTORY! " + explanation);
                        } else if ("DEFEAT".equals(status)) {
                            System.out.println("💀 DEFEAT! " + explanation);
                        } else if ("DRAW".equals(status)) {
                            System.out.println("🤝 DRAW! " + explanation);
                        } else {
                            System.out.println("ℹ️ GAME OVER: " + status + " - " + explanation);
                        }
                        System.out.println("*******************************************************\n");
                        return;

                    case "ERROR":
                        System.out.println("❌ [SERVER ERROR]: " + line);
                        return;
                }
            }

        } catch (ConnectException e) {
            System.err.println("[ERROR] Could not connect to " + host + ":" + port + ". Ensure TicTacToeServer is running!");
        } catch (IOException e) {
            System.err.println("[CLIENT EXCEPTION] " + e.getMessage());
        } finally {
            // >>> FILL IN THE BLANK [8]: Close client socket cleanly <<<
            // if (socket != null && !socket.isClosed()) {
            //     try { socket.close(); } catch (IOException ignored) {}
            // }
            System.out.println("[CLIENT] 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);
    }
}