package upem.net.tcp.nonblocking;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.util.Set;

public class ServerNonBlocking {

    private final ServerSocketChannel serverSocketChannel;
    private final Selector selector;
    private final Set<SelectionKey> selectedKeys;

    public ServerNonBlocking(int port) throws IOException {
        serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.bind(new InetSocketAddress(port));
        selector = Selector.open();
        selectedKeys = selector.selectedKeys();
    }

    public void launch() throws IOException {
        serverSocketChannel.configureBlocking(false);
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
        Set<SelectionKey> selectedKeys = selector.selectedKeys();
        while (!Thread.interrupted()) {
            selector.select();
            processSelectedKeys();
            selectedKeys.clear();
        }
    }

    private void processSelectedKeys() {
        for (SelectionKey key : selectedKeys) {
            if (key.isValid() && key.isAcceptable()) {
                doAccept(key);
            }
            if (key.isValid() && key.isWritable()) {
                doWrite(key);
            }
            if (key.isValid() && key.isReadable()) {
                doRead(key);
            }
        }
    }

    private void doAccept(SelectionKey key) {
        // TODO

    }

    private void doRead(SelectionKey key) {
        // TODO

    }

    private void doWrite(SelectionKey key) {
        // TODO

    }



    public static void main(String[] args) throws NumberFormatException, IOException {
        new ServerNonBlocking(Integer.parseInt(args[0])).launch();

    }
}