package org.orinprojects;

import org.orinprojects.encryption.EncryptionUtil;
import org.orinprojects.exceptions.ArgumentsException;

import javax.crypto.SecretKey;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.security.KeyPair;
import java.security.NoSuchAlgorithmException;
import java.security.PublicKey;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;

public class Server {

    static List<ClientHandler> clients = new ArrayList<>();

    static Map<String, PublicKey> clientKeys = new HashMap<>();

    static ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newFixedThreadPool(20);

    static KeyPair serverKeys;

    static SecretKey aesKey;

    static byte[] ivKey;

    public static void main(String[] args) throws ArgumentsException, NoSuchAlgorithmException, IOException {
        Server.serverKeys = EncryptionUtil.generateRSAKeys();
        Server.ivKey = EncryptionUtil.generateIV();
        Server.aesKey = EncryptionUtil.generateAESKey();

        int portNumber = getPortNumber(args);

        try (ServerSocket server = new ServerSocket(portNumber)) {
            while (!server.isClosed()) {
                Socket clientSocket = server.accept();

                ClientHandler clientHandler = new ClientHandler(clientSocket);
                clients.add(clientHandler);

                executor.execute(clientHandler);
            }
        }
    }

    private static int getPortNumber(String[] args) throws ArgumentsException {
        if (args.length != 2)
            throw new ArgumentsException("Not enough or too much arguments");

        if (!args[0].equals("-p"))
            throw new ArgumentsException("No port parameter. Use -p to specify port");

        int port;
        try {
            port = Integer.parseInt(args[1]);
        } catch (NumberFormatException numberFormatException) {
            throw new ArgumentsException("Wrong number format! Example: -p 6666");
        }

        return port;
    }

}