// --- BEGIN COPYRIGHT BLOCK ---
// 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; version 2 of the License.
//
// 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.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
// (C) 2007 Red Hat, Inc.
// All rights reserved.
// --- END COPYRIGHT BLOCK ---
package com.netscape.cmsutil.ocsp;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.mozilla.jss.asn1.ANY;
import org.mozilla.jss.asn1.ASN1Template;
import org.mozilla.jss.asn1.ASN1Value;
import org.mozilla.jss.asn1.EXPLICIT;
import org.mozilla.jss.asn1.GeneralizedTime;
import org.mozilla.jss.asn1.INTEGER;
import org.mozilla.jss.asn1.InvalidBERException;
import org.mozilla.jss.asn1.SEQUENCE;
import org.mozilla.jss.asn1.Tag;
import org.mozilla.jss.pkix.cert.Extension;

/**
 * RFC 2560:
 *
 * <pre>
 * ResponseData ::= SEQUENCE {
 *    version              [0] EXPLICIT Version DEFAULT v1,
 *    responderID              ResponderID,
 *    producedAt               GeneralizedTime,
 *    responses                SEQUENCE OF SingleResponse,
 *    responseExtensions   [1] EXPLICIT Extensions OPTIONAL }
 * </pre>
 *
 * @version $Revision$ $Date$
 */
public class ResponseData implements ASN1Value {
    private static final INTEGER v1 = new INTEGER(0);
    private INTEGER mVer;
    private ResponderID mRID = null;
    private GeneralizedTime mProduced = null;
    private SingleResponse mSR[] = null;
    private Extension mExts[] = null;

    private static final Tag TAG = SEQUENCE.TAG;

    public ResponseData(INTEGER ver, ResponderID rid, GeneralizedTime produced,
            SingleResponse sr[], Extension exts[]) {
        mVer = (ver != null) ? ver : v1;
        mRID = rid;
        mProduced = produced;
        mSR = sr;
        mExts = exts;
    }

    public ResponseData(ResponderID rid, GeneralizedTime produced,
            SingleResponse sr[]) {
        this(v1, rid, produced, sr, null);
    }

    public ResponseData(ResponderID rid, GeneralizedTime produced,
            SingleResponse sr[], Extension exts[]) {
        this(v1, rid, produced, sr, exts);
    }

    public Tag getTag() {
        return TAG;
    }

    public void encode(OutputStream os) throws IOException {
        encode(null, os);
    }

    public void encode(Tag t, OutputStream os) throws IOException {
        SEQUENCE seq = new SEQUENCE();

        if (mVer != v1) {
            seq.addElement(new EXPLICIT(Tag.get(0), new INTEGER(mVer)));
        }

        seq.addElement(new EXPLICIT(mRID.getTag(), mRID));
        seq.addElement(mProduced);
        SEQUENCE responses = new SEQUENCE();
        for (int i = 0; i < mSR.length; i++) {
            responses.addElement(mSR[i]);
        }
        seq.addElement(responses);
        if (mExts != null) {
            SEQUENCE exts = new SEQUENCE();
            for (int i = 0; i < mExts.length; i++) {
                exts.addElement(mExts[i]);
            }
            seq.addElement(new EXPLICIT(Tag.get(1), exts));
        }
        if (t == null) {
            seq.encode(os);
        } else {
            seq.encode(t, os);
        }
    }

    public ResponderID getResponderID() {
        return mRID;
    }

    public GeneralizedTime getProducedAt() {
        return mProduced;
    }

    public int getResponseCount() {
        return (mSR != null) ? mSR.length : 0;
    }

    public SingleResponse getResponseAt(int pos) {
        return (mSR != null) ? mSR[pos] : null;
    }

    public int getResponseExtensionCount() {
        return (mExts != null) ? mExts.length : 0;
    }

    public Extension getResponseExtensionAt(int pos) {
        return (mExts != null) ? mExts[pos] : null;
    }

    private static final Template templateInstance = new Template();

    public static Template getTemplate() {
        return templateInstance;
    }

    /**
     * A Template for decoding <code>ResponseBytes</code>.
     */
    public static class Template implements ASN1Template {

        private SEQUENCE.Template seqt;

        public Template() {
            seqt = new SEQUENCE.Template();
            seqt.addOptionalElement(new EXPLICIT.Template(
                    new Tag(0), new INTEGER.Template()));
            seqt.addElement(new ANY.Template());
            seqt.addElement(new GeneralizedTime.Template());
            seqt.addElement(new SEQUENCE.OF_Template(
                    SingleResponse.getTemplate()));
            seqt.addOptionalElement(new EXPLICIT.Template(
                    new Tag(1), new SEQUENCE.OF_Template(
                            Extension.getTemplate())));
        }

        public boolean tagMatch(Tag tag) {
            return TAG.equals(tag);
        }

        public ASN1Value decode(InputStream istream)
                throws InvalidBERException, IOException {
            return decode(TAG, istream);
        }

        public ASN1Value decode(Tag implicitTag, InputStream istream)
                throws InvalidBERException, IOException {
            SEQUENCE seq = (SEQUENCE) seqt.decode(implicitTag,
                    istream);

            INTEGER ver = v1;
            EXPLICIT e_ver = (EXPLICIT) seq.elementAt(0);
            if (e_ver != null && e_ver.getTag().getNum() == 0) {
                ver = (INTEGER) e_ver.getContent();
            }
            ResponderID rid = null;
            ANY e_rid = (ANY) seq.elementAt(1);
            if (e_rid.getTag().getNum() == 1) {
                // name id
                rid = (NameID)
                        NameID.getTemplate().decode(e_rid.getTag(),
                                new ByteArrayInputStream(e_rid.getEncoded()));
            } else if (e_rid.getTag().getNum() == 2) {
                // key hash id
                rid = (KeyHashID)
                        KeyHashID.getTemplate().decode(e_rid.getTag(),
                                new ByteArrayInputStream(e_rid.getEncoded()));
            }
            GeneralizedTime producedAt = (GeneralizedTime) seq.elementAt(2);
            SEQUENCE responses = (SEQUENCE) seq.elementAt(3);
            SingleResponse sr[] = null;
            if ((responses != null) && (responses.size() > 0)) {
                sr = new SingleResponse[responses.size()];
                for (int i = 0; i < responses.size(); i++) {
                    sr[i] = (SingleResponse) responses.elementAt(i);
                }
            }

            //decode response extension sequence
            EXPLICIT extns_exp = (EXPLICIT) seq.elementAt(4);
            SEQUENCE extns_seq;
            Extension[] extns_array = null;
            if (extns_exp != null) {
                extns_seq = (SEQUENCE) extns_exp.getContent();
                extns_array = new Extension[extns_seq.size()];
                for (int x = 0; x < extns_array.length; x++) {
                    extns_array[x] = (Extension) extns_seq.elementAt(x);
                }
            }

            return new ResponseData(ver, rid, producedAt, sr, extns_array);
        }
    }
}