/* Submit : A Course Project Submission Program
 *
 * Copyright (C) 1998 Alexander V. Konstantinou (akonstan@acm.org)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 *
 * $Id: ZipFileUtils.java,v 1.1 1998/11/19 19:50:16 akonstan Exp $
 */

package org.acm.akonstan.util;

import java.io.*;
import java.util.Stack;
import java.util.Vector;
import java.util.Enumeration;
import java.util.zip.*;

public class ZipFileUtils {
  /**
   * Zip archives appear to use the '/' character as a separator independent
   * of the host file system convention.
   * <P>
   * @version $Revision: 1.1 $ ; $Date: 1998/11/19 19:50:16 $
   * @author Alexander V. Konstantinou (akonstan@acm.org)        
   */
  public static final String zipSeparator = "/";
  
  /**
   * Zips recursively the contents of the source directory (srcDir) into
   * the OutputStream out.  If the verbose flag is set, the program
   * will output the files added to System.out.  The files are relative to
   * the parent of the srcDir parameter.
   */
  public static void CreateZipFile(File srcDir, OutputStream out,
				   boolean verbose) 
    throws IOException {
    
    Vector fileVector = listRecursive(srcDir);
    ZipOutputStream zout = new ZipOutputStream(out);
    
    zout.setLevel(9);
    zout.setComment("CreateZipFile Archive");
    
    for(Enumeration en = fileVector.elements(); en.hasMoreElements(); ) {
      String filename = (String) en.nextElement();
      File file = new File(srcDir.getParent(), filename);
      
      if (verbose) System.out.println("  adding: " + filename);

      String zipFilename = filename;
      // Convert filename to Zip separator format
      if (File.separator.charAt(0) != zipSeparator.charAt(0)) {
	zipFilename = filename.replace(File.separator.charAt(0), zipSeparator.charAt(0));
      }
      if (file.isFile()) {
	ZipEntry ze = new ZipEntry(zipFilename);
	
	zout.putNextEntry(ze);
	
	FileInputStream fin = new FileInputStream(file);
	BufferedInputStream bis = new BufferedInputStream(fin);
	byte[] buffer = new byte[4096];
	
	int n = 0;
	do {
	  n = bis.read(buffer, 0, 4096);
	  if (n != -1) zout.write(buffer, 0, n);
	} while (n != -1);
	
	fin.close();
      } else {
	/* ZipFile directory names must end in a zipSeparator */
	ZipEntry ze = new ZipEntry(zipFilename + zipSeparator);
	zout.putNextEntry(ze);
	}
    } // for (fileVector enumeration)

    zout.close();
  } // CreateZipFile

  /**
   * Returns a Vector of Strings containing a recursive listing of all
   * files in the source directory.  This list does not include the
   * current directory or the parent directory, and is always relative
   * to the parent directory.
   */
  public static Vector listRecursive(File directory) 
    throws SecurityException, IOException {
    
    Stack explore = new Stack();
    Vector result = new Vector();
    String root = directory.getParent();

    // Schedule the directory for exploration
    explore.push(directory.getName());

    // While there are directories left to explore
    while(!explore.empty()) {
      String current = (String) explore.pop();
      File curDir = new File(root, current);
      String[] fileList = curDir.list();

      if (fileList != null) {
	for(int i=0; i<fileList.length; i++) {
	  File f = new File(curDir, fileList[i]);
	  if (f.isFile()) {
	    if (f.canRead()) {
	      result.addElement(current + File.separator + fileList[i]);
	    } else {
	      // XXX - hack for .nfs files causing problems
	      if (f.getName().startsWith(".nfs", 0)) {
		System.err.println("Warning: ignoring temporary NFS file " +
				   f.getPath());
	      } else {
		System.err.println("File " + f.getPath() + " is unreadable !");
		throw new IOException("Permission denied");
	      }
	    }
	  } else if (f.isDirectory()) {
	    result.addElement(current + File.separator + fileList[i]);
	    explore.push(current + File.separator + f.getName());
	  } else {
	    throw new IOException("Unknown file type for file "+f.getPath());
	  }
	} // for (every file in directory)
      } // if (fileList != null)
    } // while (stack not empty)

    return result;
  }
} // ZipFileUtils