/**
 * Copyright (C) 2010-2017 Gordon Fraser, Andrea Arcuri and EvoSuite
 * contributors
 *
 * This file is part of EvoSuite.
 *
 * EvoSuite is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3.0 of the License, or
 * (at your option) any later version.
 *
 * EvoSuite is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with EvoSuite. If not, see <http://www.gnu.org/licenses/>.
 */
package org.evosuite.runtime.vnet;

import java.io.IOException;

import org.evosuite.runtime.mock.java.net.SocketIn;
import org.evosuite.runtime.mock.java.net.SocketOut;
import org.evosuite.runtime.vnet.VirtualNetwork.ConnectionType;

/**
 * Class used to represent a remote TCP server, listening to a specific port.
 * The simulated server will handle only one incoming connections.
 * To simulate the accepting of several connection on same port, different
 * instances of this class will be needed. 
 * It is possible to have more than one "server" on same port. 
 * 
 * @author arcuri
 *
 */
public class RemoteTcpServer {

	/**
	 * Connection (if any) toward the SUT
	 */
	private final NativeTcp connection;
	
	private final SocketOut out;
	
	private final SocketIn in;

    /**
     *
     * @param address of the remote server
     * @throws IllegalArgumentException
     */
	public RemoteTcpServer(EndPointInfo address) throws IllegalArgumentException{
		if(!address.getType().equals(ConnectionType.TCP)){
			throw new IllegalArgumentException("Invalid type: "+address.getType());
		}
		connection = new NativeTcp(null, address);	
		in = new SocketIn(connection, false);
		out = new SocketOut(connection, false);
	}

	public EndPointInfo getAddress() {
		return connection.getRemoteEndPoint();
	}
	
	/**
	 * This will be called by the virtual network when the
	 * system under test will try to connect to this server
	 * 
	 * @throws IOException
	 */
	public synchronized NativeTcp connect(EndPointInfo sutAddress) throws IOException{
		if(this.connection.isBound()){
			throw new IOException("Server is already connected");
		}
		
		if(sutAddress == null){
			throw new IOException("Null local SUT address");
		}
		
		connection.bind(sutAddress);
		return connection;
	}
	
	public boolean sendMessage(String msg){
		//note: we can send even if connection is not bound yet (msg will be on a buffer)
		
		try {
			out.write(msg.getBytes());
		} catch (IOException e) {
			return false;
		}
		return true;
	}
	
	public String getAllReceivedDataAsString(){
		if(!connection.isBound()){
			return null;
		}
		
		try {
			byte[] buffer = new byte[in.available()];
			in.read(buffer);
			return new String(buffer);
		} catch (IOException e) {
			return null;
		}
	}
}