/*
 *
 * Copyright (c) 2013 - 2017 Lijun Liao
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3
 * as published by the Free Software Foundation with the addition of the
 * following permission added to Section 15 as permitted in Section 7(a):
 *
 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
 * THE AUTHOR LIJUN LIAO. LIJUN LIAO DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
 * OF THIRD PARTY RIGHTS.
 *
 * 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License.
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial activities involving the XiPKI software without
 * disclosing the source code of your own applications.
 *
 * For more information, please contact Lijun Liao at this
 * address: lijun.liao@gmail.com
 */

package org.xipki.pki.scep.client;

import java.security.cert.CertificateEncodingException;
import java.security.cert.X509Certificate;
import java.util.concurrent.ConcurrentHashMap;

import org.xipki.commons.common.util.ParamUtil;
import org.xipki.pki.scep.crypto.ScepHashAlgoType;

/**
 * @author Lijun Liao
 * @since 2.0.0
 */

public final class CachingCertificateValidator implements CaCertValidator {

    private final ConcurrentHashMap<String, Boolean> cachedAnswers;

    private final CaCertValidator delegate;

    public CachingCertificateValidator(final CaCertValidator delegate) {
        this.delegate = ParamUtil.requireNonNull("delegate", delegate);
        this.cachedAnswers = new ConcurrentHashMap<String, Boolean>();
    }

    @Override
    public boolean isTrusted(final X509Certificate cert) {
        ParamUtil.requireNonNull("cert", cert);
        String hexFp;
        try {
            hexFp = ScepHashAlgoType.SHA256.hexDigest(cert.getEncoded());
        } catch (CertificateEncodingException ex) {
            return false;
        }

        Boolean bo = cachedAnswers.get(hexFp);

        if (bo != null) {
            return bo.booleanValue();
        } else {
            boolean answer = delegate.isTrusted(cert);
            cachedAnswers.put(hexFp, answer);
            return answer;
        }
    }

}