package robot;

import sun.nio.ch.ThreadPool;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;

enum ServerResponse{
    LOGIN("200 LOGIN \r\n"),
    PASSWORD("201 PASSWORD \r\n"),
    OK("200 OK \r\n"),
    BADCHECKSUM("300 BAD CHECKSUM \r\n"),
    BADAUTHROZATION("500 LOGIN FAILED \r\n"),
    BADSYNTAX("501 SYNTAX ERROR \r\n"),
    TIMEOUT("502 TIMEOUT \r\n");


    private String value;
    ServerResponse(String value){
        this.value = value;
    }

    public String getValue() {
        return value;
    }
}

class InputValidator{
    static char[] robotSyntax = {'R','o','b','o','t'};
    public static boolean isRobot(char c, int position){
        return robotSyntax[position] == c;
    }
    public static int getLength(){
        return robotSyntax.length;
    }
}

class ThreadWorker implements Runnable{
    private Socket clientSocket;
    private BufferedReader bufferedReader;
    PrintWriter outputStream;
    public ThreadWorker(Socket clientSocket) throws SocketException {
        this.clientSocket = clientSocket;
        clientSocket.setSoTimeout(45/60);
        System.out.println("client accepted from: " + clientSocket.getInetAddress()
                + ":" + clientSocket.getPort());
    }

    @Override
    public void run() {
        try {
            outputStream = new PrintWriter(clientSocket.getOutputStream());
            outputStream.println(ServerResponse.LOGIN);
            outputStream.flush();
            int status = 1;
            char previouschar = 0;
            char input;
            int value;
            int readedchars = 0;
            StringBuilder stringBuilder = new StringBuilder();
            //Thread.sleep(30000);
            while (true){
                bufferedReader = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
                if (status == 1){
                    boolean isrobot= false;
                    int position = 0;
                    while ((value = bufferedReader.read()) != -1 && previouschar != 13 && value != 10){
                        input = (char)value;
                        if (InputValidator.isRobot(input,position)){
                            isrobot = true;
                            previouschar = input;
                            if (position != InputValidator.getLength() -1){
                                position+=1;
                            }
                        }
                        else if (isrobot && readedchars == 5){
                            if (input != ' '){
                                outputStream.println(ServerResponse.BADSYNTAX);
                                outputStream.flush();
                                outputStream.close();
                                clientSocket.close();
                            }
                        }
                        else if (isrobot && readedchars > 5){
                            stringBuilder.append(input);
                            previouschar = input;
                        }
                        else {
                            outputStream.println(ServerResponse.BADSYNTAX);
                            outputStream.flush();
                            outputStream.close();
                            clientSocket.close();
                        }
                        readedchars++;
                    }
                    status = 2;
                    outputStream.println(ServerResponse.PASSWORD);
                    outputStream.flush();
                    System.out.println(stringBuilder);
                }
                else if (status == 2){
                    StringBuilder passBuilder = new StringBuilder();
                    int checksum = 0;
                    while ((value = bufferedReader.read()) != -1 && previouschar != 13 && value != 10){
                        if (48 <value && value < 57){
                            previouschar = (char) value;
                            passBuilder.append((char) value);
                        }
                        else {
                            outputStream.println(ServerResponse.BADAUTHROZATION);
                            outputStream.flush();
                            outputStream.close();
                            clientSocket.close();
                            break;
                        }
                    }
                    for (int i = 0; i < stringBuilder.length(); i++) {
                        checksum += (int)stringBuilder.charAt(i);
                    }
                    if (passBuilder.length() > 0){
                        try{
                            if (checksum == Integer.parseInt(passBuilder.toString())){
                                outputStream.println(ServerResponse.OK);
                                outputStream.flush();
                            }
                            else {
                                outputStream.println(ServerResponse.BADAUTHROZATION);
                                outputStream.flush();
                                outputStream.close();
                                clientSocket.close();
                            }
                        } catch (NumberFormatException e){
                            outputStream.println(ServerResponse.BADAUTHROZATION);
                            outputStream.flush();
                            outputStream.close();
                            clientSocket.close();
                        }
                    }
                    status = 3;
                }
                else if (status == 3){
                    int position = 0;
                    while ((value = bufferedReader.read()) != -1 && previouschar != 13 && value != 10){
                        if ()
                    }
                }

            }
        } catch (IOException e) {
            System.err.println("Couldn't get I/O.");
            System.exit(1);
        }
    }
}


class TCPServer{
    private ServerSocket serverSocket;
    public void main(int port){
        try {
            serverSocket = new ServerSocket(port);
            System.out.println("Vytvoren server");

                ThreadWorker worker = new ThreadWorker(serverSocket.accept());
                worker.run();

        } catch (IOException e) {
            System.err.println("Could not listen on port: " + port);
            System.exit(1);
        }
    }
}

public class Robot {
    public static void main(String[] args) {
        Integer port = Integer.parseInt(args[0]);
        if (3000 <= port && port <= 3900){
            if (args.length != 0 ){
                TCPServer server = new TCPServer();
                server.main(port);
            }
            else {
                System.err.println("Server: java robot.Robot <port>");
            }
        }
        else {
            System.err.println("INVALID PORT");
        }

    }
}