package gnu.crypto.keyring;  // -*- c-basic-offset: 3 -*-

// ---------------------------------------------------------------------------
// $Id: EnvelopeEntry.java,v 1.9 2005/10/06 04:24:16 rsdio Exp $
//
// Copyright (C) 2003 Free Software Foundation, Inc.
//
// This file is part of GNU Crypto.
//
// GNU Crypto 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, or (at your option)
// any later version.
//
// GNU Crypto 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; see the file COPYING.  If not, write to the
//
//    Free Software Foundation Inc.,
//    51 Franklin Street, Fifth Floor,
//    Boston, MA 02110-1301
//    USA
//
// Linking this library statically or dynamically with other modules is
// making a combined work based on this library.  Thus, the terms and
// conditions of the GNU General Public License cover the whole
// combination.
//
// As a special exception, the copyright holders of this library give
// you permission to link this library with independent modules to
// produce an executable, regardless of the license terms of these
// independent modules, and to copy and distribute the resulting
// executable under terms of your choice, provided that you also meet,
// for each linked independent module, the terms and conditions of the
// license of that module.  An independent module is a module which is
// not derived from or based on this library.  If you modify this
// library, you may extend this exception to your version of the
// library, but you are not obligated to do so.  If you do not wish to
// do so, delete this exception statement from your version.
//
// ---------------------------------------------------------------------------

import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.StringTokenizer;

/**
 * An envelope entry is a generic container for some number of primitive
 * and other envelope entries.
 */
public abstract class EnvelopeEntry extends Entry {

   // Fields.
   // ------------------------------------------------------------------------

   /** The envelope that contains this one (if any). */
   protected EnvelopeEntry containingEnvelope;

   /** The contained entries. */
   protected List entries;

   // Constructor.
   // ------------------------------------------------------------------------

   public EnvelopeEntry(int type, Properties properties) {
      super(type, properties);
      entries = new LinkedList();
      if (this.properties.get("alias-list") != null) {
         this.properties.remove("alias-list");
      }
   }

   protected EnvelopeEntry(int type) {
      super (type);
      entries = new LinkedList();
   }

   // Instance methods.
   // ------------------------------------------------------------------------

   /**
    * Adds an entry to this envelope.
    *
    * @param entry The entry to add.
    */
   public void add(Entry entry) {
      if (!containsEntry(entry)) {
         if (entry instanceof EnvelopeEntry) {
            ((EnvelopeEntry) entry).setContainingEnvelope(this);
         }
         entries.add(entry);
         payload = null;
         makeAliasList();
      }
   }

   /**
    * Tests if this envelope contains a primitive entry with the
    * given alias.
    *
    * @param alias The alias to test.
    * @return True if this envelope (or one of the contained envelopes)
    *   contains a primitive entry with the given alias.
    */
   public boolean containsAlias(String alias) {
      String aliases = getAliasList();
      if (aliases == null) {
         return false;
      }
      StringTokenizer tok = new StringTokenizer(aliases, ";");
      while (tok.hasMoreTokens()) {
         if (tok.nextToken().equals(alias)) {
            return true;
         }
      }
      return false;
   }

   /**
    * Tests if this envelope contains the given entry.
    *
    * @param entry The entry to test.
    * @return True if this envelope contains the given entry.
    */
   public boolean containsEntry(Entry entry) {
      if (entry instanceof EnvelopeEntry) {
         return entries.contains(entry);
      } else if (entry instanceof PrimitiveEntry) {
         for (Iterator it = entries.iterator(); it.hasNext(); ) {
            Entry e = (Entry) it.next();
            if (e.equals(entry))
               return true;
            if ((e instanceof EnvelopeEntry) &&
                ((EnvelopeEntry) e).containsEntry(entry))
               return true;
         }
      }
      return false;
   }

   /**
    * Returns a copy of all entries this envelope contains.
    *
    * @return All contained entries.
    */
   public List getEntries() {
      return new ArrayList(entries);
   }

   /**
    * Gets all primitive entries that have the given alias. If there
    * are any masked entries that contain the given alias, they will
    * be returned as well.
    *
    * @param alias The alias of the entries to get.
    * @return A list of all primitive entries that have the given alias.
    */
   public List get(String alias) {
      List result = new LinkedList();
      for (Iterator it = entries.iterator(); it.hasNext(); ) {
         Entry e = (Entry) it.next();
         if (e instanceof EnvelopeEntry) {
            if (!((EnvelopeEntry) e).containsAlias(alias)) {
               continue;
            }
            if (e instanceof MaskableEnvelopeEntry) {
               if (((MaskableEnvelopeEntry) e).isMasked()) {
                  result.add(e);
                  continue;
               }
            }
            result.addAll(((EnvelopeEntry) e).get(alias));
         } else if (e instanceof PrimitiveEntry) {
            if (((PrimitiveEntry) e).getAlias().equals(alias)) {
               result.add(e);
            }
         }
      }
      return result;
   }

   /**
    * Returns the list of all aliases contained by this envelope,
    * separated by a semicolon (';').
    *
    * @return The list of aliases.
    */
   public String getAliasList() {
      String list = properties.get("alias-list");
      if (list == null) {
         return "";
      } else {
         return list;
      }
   }

   /**
    * Removes the specified entry.
    *
    * @param entry The entry.
    * @return True if an entry was removed.
    */
   public boolean remove(Entry entry) {
      boolean ret = false;
      for (Iterator it = entries.iterator(); it.hasNext(); ) {
         Entry e = (Entry) it.next();
         if (e instanceof EnvelopeEntry) {
            if (e == entry) {
               it.remove();
               ret = true;
               break;
            }
            if (((EnvelopeEntry) e).remove(entry)) {
               ret = true;
               break;
            }
         } else if (e instanceof PrimitiveEntry) {
            if (((PrimitiveEntry) e).equals(entry)) {
               it.remove();
               ret = true;
               break;
            }
         }
      }
      if (ret) {
         payload = null;
         makeAliasList();
      }
      return ret;
   }

   /**
    * Removes all primitive entries that have the specified alias.
    *
    * @param alias The alias of the entries to remove.
    */
   public void remove(String alias) {
      for (Iterator it = entries.iterator(); it.hasNext(); ) {
         Entry e = (Entry) it.next();
         if (e instanceof EnvelopeEntry) {
            ((EnvelopeEntry) e).remove(alias);
         } else if (e instanceof PrimitiveEntry) {
            if (((PrimitiveEntry) e).getAlias().equals(alias)) {
               it.remove();
            }
         }
      }
      payload = null;
      makeAliasList();
   }

   // Protected methods.
   // ------------------------------------------------------------------------

   protected void encodePayload() throws IOException {
      ByteArrayOutputStream bout = new ByteArrayOutputStream(1024);
      DataOutputStream out = new DataOutputStream(bout);
      for (Iterator it = entries.iterator(); it.hasNext(); ) {
         ((Entry) it.next()).encode(out);
      }
   }

   protected void setContainingEnvelope(EnvelopeEntry e) {
      if (containingEnvelope != null) {
         throw new IllegalArgumentException("envelopes may not be shared");
      }
      containingEnvelope = e;
   }

   protected void decodeEnvelope(DataInputStream in) throws IOException {
      while (true) {
         int type = in.read();
         switch (type) {
            case EncryptedEntry.TYPE:
               add(EncryptedEntry.decode(in));
               break;
            case PasswordEncryptedEntry.TYPE:
               add(PasswordEncryptedEntry.decode(in));
               break;
            case PasswordAuthenticatedEntry.TYPE:
               add(PasswordAuthenticatedEntry.decode(in));
               break;
            case AuthenticatedEntry.TYPE:
               add(AuthenticatedEntry.decode(in));
               break;
            case CompressedEntry.TYPE:
               add(CompressedEntry.decode(in));
               break;
            case CertificateEntry.TYPE:
               add(CertificateEntry.decode(in));
               break;
            case PublicKeyEntry.TYPE:
               add(PublicKeyEntry.decode(in));
               break;
            case PrivateKeyEntry.TYPE:
               add(PrivateKeyEntry.decode(in));
               break;
            case CertPathEntry.TYPE:
               add(CertPathEntry.decode(in));
               break;
            case BinaryDataEntry.TYPE:
               add(BinaryDataEntry.decode(in));
               break;
            case -1:
               return;
            default:
               throw new MalformedKeyringException("unknown type " + type);
         }
      }
   }

   // Own methods.
   // ------------------------------------------------------------------------

   private void makeAliasList() {
      if (entries.isEmpty())
         return;
      StringBuffer buf = new StringBuffer();
      for (Iterator it = entries.iterator(); it.hasNext(); ) {
         Entry entry = (Entry) it.next();
         if (entry instanceof EnvelopeEntry) {
            buf.append(((EnvelopeEntry) entry).getAliasList());
         } else if (entry instanceof PrimitiveEntry) {
            buf.append(((PrimitiveEntry) entry).getAlias());
         }
         if (it.hasNext())
            buf.append(';');
      }
      properties.put("alias-list", buf.toString());
      if (containingEnvelope != null) {
         containingEnvelope.makeAliasList();
      }
   }
}
