//
// ReadTextFile.java
//

/*
This source file is part of the edu.wisc.ssec.mcidas package and is
Copyright (C) 1998 - 2017 by Tom Whittaker, Tommy Jasmin, Tom Rink,
Don Murray, James Kelly, Bill Hibbard, Dave Glowacki, Curtis Rueden
and others.
 
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

This library 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA
*/

package edu.wisc.ssec.mcidas.adde;

import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.lang.*;
import java.util.*;

/** 
 * ReadTextFile interface for McIDAS ADDE data sets.  
 *
 * <pre>
 * URLs must all have the following format   
 *   adde://host/text?file=filename.ext
 *
 * there can be any valid combination of the following supported keywords:
 *
 *   file - name of text file on ADDE server
 *
 * the following keywords are required:
 *
 *   file
 *
 * an example URL might look like:
 *   adde://viper/text?file=filename.ext
 * </pre>
 *
 * @author Tom Whittaker (derived from DataSetInfo by Don Murray)
 * 
 */
public class ReadTextFile 
{

    // load protocol for ADDE URLs
    // See java.net.URL for explanation of URL handling
    static 
    {
        try 
        {
            String handlers = System.getProperty("java.protocol.handler.pkgs");
            String newProperty = null;
            if (handlers == null)
                newProperty = "edu.wisc.ssec.mcidas";
            else if (handlers.indexOf("edu.wisc.ssec.mcidas") < 0)
                newProperty = "edu.wisc.ssec.mcidas | " + handlers;
            if (newProperty != null)  // was set above
                System.setProperty("java.protocol.handler.pkgs", newProperty);
        }
        catch (Exception e)
        {
            System.out.println(
                "Unable to set System Property: java.protocol.handler.pkgs"); 
        }
    }

    private int status=0;                 // read status
    private String statusString = null;
    private boolean debug = false;        // debug
    private Vector linesOfText = null;
    private URLConnection urlc;           
    private DataInputStream dis;
    
    /**
     * creates a ReadTextFile object that allows reading an ADDE
     * text file or TEXT dataset
     *
     * @param request ADDE URL to read from.  See class javadoc.
     *
     * <pre>
     * an example URL might look like:
     *   adde://viper/datasetinfo?group=gvar&descr=FILE=RESOLV.SRV
     * </pre>
     *
     * @exception AddeURLException if there are no datasets of the particular
     *            type or there is an error reading data
     *
     */
    public ReadTextFile(String request) {
   
      status = 0;
      statusString = "OK";
      try {
          URL url = new URL(request);
          if (debug) System.out.println("Request: "+request);
          urlc = url.openConnection();
          InputStream is = urlc.getInputStream();
          dis = new DataInputStream(is);
      }
      catch (AddeURLException ae) 
      {
          status = -1;
          statusString = "No file found";
          String aes = ae.toString();
          if (aes.indexOf(" Accounting ") != -1) {
            statusString = "No accounting data";
            status = -3;
          }
          if (debug) System.out.println("ReadText AF Exception:"+aes);
      }
      catch (Exception e) 
      {
          status = -2;
          if (debug) System.out.println("ReadText Exception:"+e);
          statusString = "Error opening connection: "+e;
      }

     int numBytes;
     linesOfText = new Vector();

     if (status == 0) {

       try {
         numBytes = ((AddeURLConnection) urlc).getInitialRecordSize();
         if (debug) 
          System.out.println("ReadTextFile: initial numBytes = " + numBytes);

         numBytes = dis.readInt();
          while ((numBytes = dis.readInt()) != 0) {

            if (debug) 
               System.out.println("ReadTextFile: numBytes = " + numBytes);

              byte[] data = new byte[numBytes];
              dis.readFully(data,0,numBytes);
              String s = new String(data);
              if (debug) System.out.println(s);
              linesOfText.addElement(s);
         } 

       } catch (Exception iox) {
         statusString = " "+iox;
         System.out.println(" "+iox);
       }
       
       if (linesOfText.size() < 1) statusString = "No data read";
       status = linesOfText.size();
     }
    }

    public String getStatus() {
      return statusString;
    }
    public int getStatusCode() {
      return status;
    }

    public Vector getText() {
      return linesOfText;
    }
 



    /** test by running 'java edu.wisc.ssec.mcidas.adde.ReadTextFile' */
    public static void main (String[] args)
        throws Exception
    {
        String request = (args.length == 0)
          ? "adde://adde.ucar.edu/text?file=PUBLIC.SRV"
          : args[0];

        ReadTextFile rtf = new ReadTextFile(request);
        String status = rtf.getStatus();
        System.out.println("Status = "+status);
        if (status.equals("OK")) {
          Vector l = rtf.getText();
          for (int i=0; i<l.size(); i++) {
            System.out.println( (String)l.elementAt(i));
          }
        }
    }
}