/*************************************************************************
 * 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:
 * - taille du nom du fichier sur un entier,
 * - taille du fichier sur un entier long,
 * - tableau de bytes contenant le nom du fichier,
 * - successions de tableaux de bytes de taille maximum 4096 octets
 * 	 correspondant aux donnees du fichier.
 *
 * ex: java FileServerNioMain 2005
 ************************************************************************/

package fileClientSenderSingle;


import java.io.FileOutputStream;
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.HeaderFTP;
import csc4509.HeaderFTPStatus;

public class FileServerReceiverMain {

	public static void main(String[] argv) {
		ServerSocketChannel listenChannel;
		ServerSocket listenSocket;
		boolean debugState = true;
		SocketChannel rwChan;
		InetSocketAddress rcvAddress;
		HeaderFTP head = null;
		ByteBuffer readBuf;
		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...");
				FileChannel fc;
				long readSize, receivedSize = 0L;
				String fileName;
				try {
					readBuf = ByteBuffer.allocate(2048);
					do {
						readSize = rwChan.read(readBuf);
						if (debugState) {
							System.out.println("	Received       : " + readSize);
						}
						receivedSize += readSize;
						readBuf.flip();
						if(head == null){
							head = new HeaderFTP(readBuf);
						}else{
							head.completeHeader(readBuf);
						}
					}while(head.getHeadStatus() != HeaderFTPStatus.HeaderCompleted);
				
					// creates a new name by appending copy
					fileName = head.getFileName();
					FileOutputStream fos = new FileOutputStream(fileName+ ".copy");
					fc = fos.getChannel();
					if (debugState) {
						System.out.println("filename:" + fileName + " filesize:" + head.getFileSize());
					}
					receivedSize = readBuf.limit() -readBuf.position() ;
					if(receivedSize > 0){
						fc.write(readBuf);
					}
					// loop to receive file content
					while (receivedSize < head.getFileSize()) {
						readBuf.clear();
						readSize = rwChan.read(readBuf);
						if (debugState) {
							System.out.println("filename:" + head.getFileName() + " filesize:"
									+ head.getFileSize()+ " receivedSize "+ receivedSize+ " readSize " + readSize);
						}
						receivedSize += readSize;
						readBuf.flip();
						fc.write(readBuf);
					}
					fos.close();
					rwChan.close();
				} catch (IOException ie) {
					ie.printStackTrace();
					return;
				}
			}
			listenChannel.close();
			listenSocket.close();
		} catch (SocketException se) {
			se.printStackTrace();
			return;
		} catch (IOException ie) {
			ie.printStackTrace();
			return;
		}
	}
}