import java.net.*;
import java.io.*;

public class IOManager
{
	public static final int OkResult=220;
	public static final int ErrorResult=500;
	private final int MaxNetworkPacket=1024;
	private final int InvalidPort=-1;
	private SocketControl mTCPSocket=null;
  private boolean mIsLoggedIn=false;
	private StringArray mAckResponseStrings;

  public IOManager()
  {
    mAckResponseStrings=new StringArray();
    mAckResponseStrings.insert("220");
  }
	public void shutdown()
	{
	  if(!mTCPSocket.isConnected())return;
	  if(isLoggedIn())quit();
	  try{mTCPSocket.closeSocket();}
	  catch(IOException exception){return;}
	}
	public boolean isConnected()
	{
	  if(mTCPSocket==null||!mTCPSocket.isConnected())return false;
	  return true;
	}
	private void isLoggedIn(boolean isLoggedIn)
	{
	  mIsLoggedIn=isLoggedIn;
	}
	public boolean isLoggedIn()
	{
	  return mIsLoggedIn;
	}
  public boolean connect(String strHost,int port)
  {  
	  int bytesRead;
	  byte streamBytes[];
	  int clientPort;
	  String strLine=new String();

		if(isConnected())return false;
		streamBytes=new byte[MaxNetworkPacket];
		InetAddress inetAddress=null;
		SocketControl socket=null;
		if(0!=strHost.length())
		{
		  try{inetAddress=InetAddress.getByName(strHost);}
		  catch(UnknownHostException exception){return false;}
		  try{socket=new SocketControl(inetAddress,port);}
		  catch(IOException exception){return false;}
		  catch(SecurityException exception){return false;}
		}
		else
		{
		  try{socket=new SocketControl("",port);}
		  catch(IOException exception){return false;}
		  catch(SecurityException exception){return false;}
		}
		if(!socket.isConnected())return false;
    strLine=socket.readLine();
		if(0==strLine.length())return false;
		clientPort=getPort(strLine);
		if(InvalidPort==clientPort)return false;
		socket.writeLine("OK");
		try{socket.closeSocket();}
		catch(IOException exception){return false;}
		if(0!=strHost.length())
		{
		  try{inetAddress=InetAddress.getByName(strHost);}
		  catch(UnknownHostException exception){return false;}
		  try{mTCPSocket=new SocketControl(inetAddress,clientPort);}
		  catch(IOException exception){return false;}
		}
		else
		{
		  try{mTCPSocket=new SocketControl("",clientPort);}
		  catch(IOException exception){return false;}
		}
    strLine=mTCPSocket.readLine();
		return isConnected();
	}
	public boolean advise(String strAddress,int port)
	{
	  String strRequest=null;
	  if(!isConnected())return false;
	  strRequest=new String("ADVISE(")+new String(strAddress)+new String(",")+String.valueOf(port)+new String(")");
	  mTCPSocket.writeLine(strRequest);
	  strRequest=mTCPSocket.readLine();
	  return true;
	}
  private String readLine(InputStream inputStream)
	{
	  byte streamByte[];
	  String strLine=new String();

    strLine=new String();
    while(true)
	  {
		  streamByte=new byte[1];
		  try{inputStream.read(streamByte);}
		  catch(IOException exception){break;}
		  if(13==streamByte[0])continue;
		  else if(10==streamByte[0])break;
		  strLine+=new String(streamByte);
	  }
	  return strLine;
	}
	private boolean writeLine(String strLine,OutputStream outputStream)
	{
	  if(0==strLine.length())return false;
	  strLine+=new String("\r\n");
	  byte streamData[]=strLine.getBytes();
	  try{outputStream.write(streamData);}
	  catch(IOException exception){return false;}
	  return true;
	}
	private int getPort(String strLine)
	{
	  String strPort;
	  int strIndex;
	  int port;
    
    strIndex=strLine.length()-1;
		port=InvalidPort;
		strPort=new String();
		if(strIndex<0)return -1;
		while(true)
		{
		  if(strIndex<0)break;
			if(' '==strLine.charAt(strIndex))break;
		  strIndex--;
		}
		strIndex++;
		if(strIndex<0)return port;
		strPort=strLine.substring(strIndex);
		return Integer.parseInt(strPort);
	}
	private boolean isInResponse(String responseString,StringArray responseStrings)
	{
	  if(0==responseString.length())return false;
	  for(int index=0;index<responseStrings.size();index++)
	  {
	    if(responseString.equals(responseStrings.getAt(index)))return true;
	  }
	  return false;
	}
	public boolean user(String strUserName,StringArray receiveStrings)
	{
	  receiveStrings.clear();
	  if(!isConnected())return false;
	  String strLine=new String("USER(")+strUserName+new String(")");
	  mTCPSocket.writeLine(strLine);
	  if(!mTCPSocket.receive(receiveStrings,mAckResponseStrings))return false;
	  isLoggedIn(true);
	  return isLoggedIn();
	}
	public boolean who(StringArray userList)
	{
	  StringArray responseLines=new StringArray();
	  userList.clear();
	  if(!isConnected())return false;
	  String strLine=new String("WHO");
	  mTCPSocket.writeLine(strLine);
	  if(!mTCPSocket.receive(responseLines,mAckResponseStrings))return false;
	  for(int index=1;index<responseLines.size()-1;index++)
	    userList.insert(responseLines.getAt(index).substring(4,responseLines.getAt(index).length()));
	  return true;
	}
	public boolean quit()
	{
	  if(!isConnected()||!isLoggedIn())return false;
	  String strLine=new String("QUIT");
	  mTCPSocket.writeLine(strLine);
	  strLine=mTCPSocket.readLine();
	  return true;
	}
	public boolean talk(String strLine)
	{
	  if(!isConnected()||0==strLine.length())return false;
	  String strString=new String("TALK(")+strLine+new String(")");
	  mTCPSocket.writeLine(strString);
	  strLine=mTCPSocket.readLine();
	  return true;
	}
	public String version()
	{
	  String strVersion=new String();
	  String strLine=new String();
	  
	  if(!isConnected())return strVersion;
	  mTCPSocket.writeLine("VERSION");
	  strLine=mTCPSocket.readLine();
	  if(mTCPSocket.OkResult!=mTCPSocket.getResultCode(strLine))return strVersion;
	  strVersion=mTCPSocket.getResult(strLine);
	  return strVersion;
	}
		
};