package sendandreceive;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;

import java.nio.channels.ClosedChannelException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;

import csc4509.MessageSequenceException;

public class SelectorFileServerMain {

	public static void main(String [] argv) {
		Selector selector;
		ServerSocketChannel listenChannel;
		ServerSocket listenSocket;

		boolean debugState = true;

		InetSocketAddress rcvAddress;

		HashMap<SelectionKey, NbFileTxter> theTxters = new HashMap<SelectionKey,NbFileTxter>();

		if (argv.length != 1) {
			System.out.println("usage: java SelectorFileServer <port>");
			return;
		}
		// creates the selector and the listener
		try {
			selector = Selector.open();

			listenChannel = ServerSocketChannel.open();
			listenSocket = listenChannel.socket();
			rcvAddress = new InetSocketAddress(Integer.parseInt(argv[0]));
			listenSocket.setReuseAddress(true);
			listenSocket.bind(rcvAddress);
			listenChannel.configureBlocking(false);
			selector = Selector.open();
			listenChannel.register(selector, SelectionKey.OP_ACCEPT);

			while(true){
				selector.select();
				Set<SelectionKey> readyKeys = selector.selectedKeys();
				if(debugState){
					System.out.println("Nb Ready keys:"+readyKeys.size());
				}
				Iterator<SelectionKey> iterator = readyKeys.iterator();
				while (iterator.hasNext()) {
					SelectionKey key = (SelectionKey) iterator.next();
					iterator.remove();
					if (key.isAcceptable()) {
						NbFileTxter txter;
						SelectionKey txterKey;
						SocketChannel chan = listenChannel.accept();
						chan.configureBlocking(false);
						txter = new NbFileTxter(chan);
						txterKey = chan.register(selector, SelectionKey.OP_READ);
						theTxters.put(txterKey,txter);
					} else if (key.isReadable()) {
						int messType;
						NbFileTxter txter = theTxters.get(key);
						try{
							messType = txter.nbrcvFile();
						}catch(MessageSequenceException me){
							me.printStackTrace();
							continue;
						}
						if(messType == -1){
							txter.close();
							theTxters.remove(key);
						}
					}
				}
			}		
		} catch (ClosedChannelException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}

	}
}