/**
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package org.apache.maven.mercury.crypto.pgp;

import java.io.InputStream;

import org.apache.maven.mercury.crypto.api.AbstractStreamVerifierFactory;
import org.apache.maven.mercury.crypto.api.StreamVerifier;
import org.apache.maven.mercury.crypto.api.StreamVerifierAttributes;
import org.apache.maven.mercury.crypto.api.StreamVerifierException;
import org.apache.maven.mercury.crypto.api.StreamVerifierFactory;
import org.bouncycastle.openpgp.PGPPrivateKey;
import org.bouncycastle.openpgp.PGPPublicKeyRingCollection;
import org.bouncycastle.openpgp.PGPSecretKey;
import org.bouncycastle.openpgp.PGPSecretKeyRing;
import org.bouncycastle.openpgp.PGPUtil;
import org.codehaus.plexus.lang.DefaultLanguage;
import org.codehaus.plexus.lang.Language;

/**
 * @author Oleg Gusakov
 * @version $Id$
 */
public class PgpStreamVerifierFactory
    extends AbstractStreamVerifierFactory
    implements StreamVerifierFactory
{

    public static final String DEFAULT_EXTENSION = PgpHelper.EXTENSION;

    private static final Language LANG = new DefaultLanguage( PgpStreamVerifierFactory.class );

    private PGPPublicKeyRingCollection trustedPublicKeyRing;

    private PGPPrivateKey privateKey;

    private int algorithm = 0;

    private int digestAlgorithm = PGPUtil.SHA512;

    // --------------------------------------------------------------------------------------------
    public PgpStreamVerifierFactory( StreamVerifierAttributes attributes, InputStream trustedPublicKeyRingStream )
        throws StreamVerifierException
    {
        super( attributes );
        init( trustedPublicKeyRingStream );

    }

    // --------------------------------------------------------------------------------------------
    public PgpStreamVerifierFactory( StreamVerifierAttributes attributes, PGPPublicKeyRingCollection publicKeyRing )
        throws StreamVerifierException
    {
        super( attributes );
        this.trustedPublicKeyRing = publicKeyRing;
    }

    // --------------------------------------------------------------------------------------------
    public PgpStreamVerifierFactory( StreamVerifierAttributes attributes, InputStream secretKeyRingStream,
                                     String secretKeyId, String secretKeyPass )
        throws StreamVerifierException
    {
        super( attributes );
        init( secretKeyRingStream, secretKeyId, secretKeyPass );
    }

    // --------------------------------------------------------------------------------------------
    public void init( InputStream trustedPublicKeyRingStream )
        throws StreamVerifierException
    {
        try
        {
            if ( trustedPublicKeyRingStream != null )
            {
                trustedPublicKeyRing =
                    new PGPPublicKeyRingCollection( PGPUtil.getDecoderStream( trustedPublicKeyRingStream ) );
                if ( trustedPublicKeyRing == null )
                    throw new StreamVerifierException( LANG.getMessage( "bad.factory.init.verify.empty" ) );
            }
            else
                throw new StreamVerifierException( LANG.getMessage( "bad.factory.init.verify" ) );
        }
        catch ( Exception e )
        {
            throw new StreamVerifierException( e );
        }
    }

    // --------------------------------------------------------------------------------------------
    public void init( InputStream secretKeyRingStream, String secretKeyId, String secretKeyPass )
        throws StreamVerifierException
    {
        try
        {
            if ( secretKeyRingStream != null && secretKeyId != null && secretKeyPass != null )
            {
                PGPSecretKeyRing secRing = PgpHelper.readKeyRing( secretKeyRingStream, secretKeyId );
                PGPSecretKey secKey = secRing.getSecretKey( PgpHelper.hexToId( secretKeyId ) );
                privateKey = secKey.extractPrivateKey( secretKeyPass.toCharArray(), PgpHelper.PROVIDER );
                algorithm = secKey.getPublicKey().getAlgorithm();
            }
            else
                throw new StreamVerifierException( LANG.getMessage( "bad.factory.init.generate" ) );
        }
        catch ( Exception e )
        {
            throw new StreamVerifierException( e );
        }
    }

    // --------------------------------------------------------------------------------------------
    public String getDefaultExtension()
    {
        return DEFAULT_EXTENSION;
    }

    // --------------------------------------------------------------------------------------------
    public StreamVerifier newInstance()
        throws StreamVerifierException
    {
        PgpStreamVerifier sv = new PgpStreamVerifier( attributes );

        if ( privateKey != null )
            sv.init( privateKey, algorithm, digestAlgorithm );

        if ( trustedPublicKeyRing != null )
            sv.init( trustedPublicKeyRing );

        return sv;
    }
    // --------------------------------------------------------------------------------------------
    // --------------------------------------------------------------------------------------------
}