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

// ---------------------------------------------------------------------------
// $Id: BaseKeyring.java,v 1.4 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.InputStream;
import java.io.IOException;
import java.io.OutputStream;

import java.util.Enumeration;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;

import gnu.crypto.Registry;

public abstract class BaseKeyring implements IKeyring {

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

   private static final IllegalStateException NOT_LOADED
      = new IllegalStateException("keyring not loaded");

   /**
    * The top-level keyring data.
    */
   protected PasswordAuthenticatedEntry keyring;

   protected CompressedEntry keyring2;

   // Constructors.
   // ------------------------------------------------------------------------

   public BaseKeyring() {
   }

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

   public void load(Map attributes) throws IOException {
      InputStream in = (InputStream) attributes.get(KEYRING_DATA_IN);
      if (in == null) {
         throw new IllegalArgumentException("no input stream");
      }
      char[] password = (char[]) attributes.get(KEYRING_PASSWORD);
      if (password == null) {
         password = new char[0];
      }

      if (in.read() != Registry.GKR_MAGIC[0] ||
          in.read() != Registry.GKR_MAGIC[1] ||
          in.read() != Registry.GKR_MAGIC[2] ||
          in.read() != Registry.GKR_MAGIC[3]) {
         throw new MalformedKeyringException("magic");
      }

      load(in, password);

      List l = keyring.getEntries();
      if (l.size() == 1 && (l.get(0) instanceof CompressedEntry)) {
         keyring2 = (CompressedEntry) l.get(0);
      }
   }

   public void store(Map attributes) throws IOException {
      OutputStream out = (OutputStream) attributes.get(KEYRING_DATA_OUT);
      if (out == null) {
         throw new IllegalArgumentException("no output stream");
      }
      char[] password = (char[]) attributes.get(KEYRING_PASSWORD);
      if (password == null) {
         password = new char[0];
      }
      if (keyring == null) {
         throw new IllegalStateException("empty keyring");
      }

      out.write(Registry.GKR_MAGIC);
      store(out, password);
   }

   public void reset() {
      keyring = null;
   }

   public int size() {
      if (keyring == null) {
         throw NOT_LOADED;
      }
      return ((StringTokenizer) aliases()).countTokens();
   }

   public Enumeration aliases() {
      if (keyring == null) {
         throw NOT_LOADED;
      }
      return new StringTokenizer(keyring.getAliasList(), ";");
   }

   public boolean containsAlias(String alias) {
      if (keyring == null) {
         throw new IllegalStateException("keyring not loaded");
      }
      return keyring.containsAlias(alias);
   }

   public List get(String alias) {
      if (keyring == null) {
         throw new IllegalStateException("keyring not loaded");
      }
      return keyring.get(alias);
   }

   public void add(Entry entry) {
      if (keyring == null) {
         throw new IllegalStateException("keyring not loaded");
      }
      if (keyring2 != null)
         keyring2.add(entry);
      else
         keyring.add(entry);
   }

   public void remove(String alias) {
      if (keyring == null) {
         throw new IllegalStateException("keyring not loaded");
      }
      keyring.remove(alias);
   }

   protected String fixAlias(String alias) {
      return alias.replace(';', '_');
   }

   protected abstract void load(InputStream in, char[] password) throws IOException;
   protected abstract void store(OutputStream out, char[] password) throws IOException;
}
