///////    CgiSocket.java    ///////
import java.io.*;
import java.net.*;

// The msg to send is assumed to be correctly encoded
// and formatted already

public class CgiSocket implements CgiClient
{  public CgiSocket(String server, int port, String cg)
   {  try
      {  host = server; cgi = cg;
         sin = new Socket(host, port);
         if ( sin == null ) System.err.println("socket failed");
         out = new PrintWriter(sin.getOutputStream());
         ins = sin.getInputStream();
      } catch (UnknownHostException e) { JavaSystem.error(e); }
        catch (IOException e) { JavaSystem.error(e); }
   }

   protected CgiSocket() {}

   /* posts the query msg, sets up input streams */
   /* This method can be called only once */
   public void postQuery(String msg)
   {  if (out != null)
      {  postHeader(msg);                  // header
         out.println(msg); out.flush();    // msg body
      }
   }

   public TextLines textResponse()
   {  if ( ins != null )
      {  TextLines from = new TextLines();
         int len = from.input(ins);
         close();
         if ( len > -1 ) return from;
      }
      return null;
   }

   public void close()
   {  try
      { if ( sin != null ) sin.close();
      } catch (IOException e) { JavaSystem.error(e); }
   }

   public String readNextLine()
   {  try
      {  if ( in == null )
              in = new BufferedReader (new InputStreamReader(ins));
          return in.readLine();
      } catch (IOException e) { JavaSystem.error(e); }
      return null;
   }

   public InputStream getInputStream()
   {   return ins;  }

   protected void postHeader(String msg)
   {  out.print("POST " + cgi + " HTTP/1.1\r\n");    // request
      out.print("HOST: " + host + "\r\n");           // host
      out.print("User-Agent: JavaCgiSocket\r\n");    // agent
      out.print("Content-Type: application/x-www-form-urlencoded\r\n");
      out.print("Content-Length: " + msg.length() + "\r\n");
      out.print("\r\n");                             // empty line
   }

   protected Socket sin;
   protected BufferedReader in;
   protected InputStream ins;
   protected PrintWriter out;
   protected String host;
   protected String cgi;
}