/*************************************************************************
 * Ce programme cree un socket TCP associe au port argv[0], attend une
 * demande de connexion, pour chaque demande de connexion. Il attend
 * la reception d'un fichier. Les donnees recues sont les suivantes:
 * <ul>
 * <li>
 * taille du nom du fichier sur un entier,
 * </li>
 * <li>
 * taille du fichier sur un entier long,
 * </li>
 * <li>
 * tableau de bytes contenant le nom du fichier,
 * </li>
 * <li>successions de tableaux de bytes de taille maximum 4096 octets
 * correspondant aux donnees du fichier.
 * </li>
 * </ul>
 *
 * ex: java FileServerNioMain 2005
 ************************************************************************/

package fileClientReceiverSingleMsg;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.SocketException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;

import csc4509.HalfDuplexFTPWorker;

import csc4509.ReadMessageStatus;
import csc4509.MessageSequenceException;
public class FileServerSenderMsgMain {
	private static boolean debugState = true;

	public static void main(String[] argv) throws MessageSequenceException {
		ServerSocketChannel listenChannel;
		ServerSocket listenSocket;
		FileChannel fc;
		FileInputStream fis;
		File file;
		ByteBuffer readBuf = ByteBuffer.allocate(4096);
		SocketChannel rwChan;
		InetSocketAddress rcvAddress;
		int i = 1;
		if (argv.length != 1) {
			System.out.println("usage: java fileServer <port>");
			return;
		}
		// on cree le socket de connexion et lui associe un port
		// accept() est bloquant jusqu'a arrivee de demande de connexion
		try {
			listenChannel = ServerSocketChannel.open();
			listenSocket = listenChannel.socket();
			rcvAddress = new InetSocketAddress(Integer.parseInt(argv[0]));
			listenSocket.setReuseAddress(true);
			listenSocket.bind(rcvAddress);
			while (i > 0) {
				// accept one incoming connection
				System.out.println("Waiting for connection request...");
				rwChan = listenChannel.accept();
				System.out.println("Connection request accepted...");
				long fileSize;
				String fileName;
				try {
					HalfDuplexFTPWorker worker = new HalfDuplexFTPWorker(rwChan);
					ReadMessageStatus status;
					int messType;
					worker.clear();
					status = worker.readMessage();
					fileName = (String) worker.getData();
					if (status != ReadMessageStatus.ReadDataCompleted) {
						System.out
								.println("Connection closed in read message 1");
						break;
					}
					messType = worker.getMessType();
					if (messType == 1) {
						fileName = (String) worker.getData();
						file = new File(fileName);
						fis = new FileInputStream(file);
						fileSize = file.length();
						fc = fis.getChannel();
						if (debugState) {
							System.out.println("filename:" + fileName
									+ " filesize:" + fileSize);
						}
					} else
						throw new MessageSequenceException(
								"Awaiting MessageType 1 and receiving "
										+ messType);
					worker.sendMsg(2, fileSize);
					sendWithLoop(fc, readBuf, worker);
					fc.close();
					fis.close();
					rwChan.close();
					worker.close();
				} catch (IOException ie) {
					ie.printStackTrace();
					return;
				}
			}
			listenChannel.close();
			listenSocket.close();
		} catch (SocketException se) {
			se.printStackTrace();
			return;
		} catch (IOException ie) {
			ie.printStackTrace();
			return;
		}
	}

	static void sendWithLoop(FileChannel fc, ByteBuffer readBuf,
			HalfDuplexFTPWorker worker) throws IOException {
		// loop to send file content
		int readSize = 0;
		do {
			// lecture d'un bloc du fichier original
			readSize = fc.read(readBuf);
			if (debugState) {
				System.out.println("Read size : " + readSize);
			}
			if (readSize > 0) {
				worker.setHeader(3, readSize);
				readBuf.flip();
				worker.setDataByteBuffer(readBuf);
				worker.sendBuffers();
				readBuf.clear();
			}
		} while (readSize > 0);
	}
}