/*
 * The contents of this file are subject to the terms of the Common Development and
 * Distribution License (the License). You may not use this file except in compliance with the
 * License.
 *
 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
 * specific language governing permission and limitations under the License.
 *
 * When distributing Covered Software, include this CDDL Header Notice in each file and include
 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
 * Header, with the fields enclosed by brackets [] replaced by your own identifying
 * information: "Portions Copyright [year] [name of copyright owner]".
 *
 * Copyright 2010 Sun Microsystems, Inc.
 * Portions copyright 2013-2016 ForgeRock AS.
 */
package com.forgerock.opendj.ldap.extensions;

import java.io.IOException;

import org.forgerock.i18n.LocalizableMessage;
import org.forgerock.opendj.io.ASN1;
import org.forgerock.opendj.io.ASN1Reader;
import org.forgerock.opendj.ldap.ByteString;
import org.forgerock.opendj.ldap.DecodeException;
import org.forgerock.opendj.ldap.DecodeOptions;
import org.forgerock.opendj.ldap.ResultCode;
import org.forgerock.opendj.ldap.controls.Control;
import org.forgerock.opendj.ldap.requests.AbstractExtendedRequest;
import org.forgerock.opendj.ldap.requests.ExtendedRequest;
import org.forgerock.opendj.ldap.requests.ExtendedRequestDecoder;
import org.forgerock.opendj.ldap.responses.AbstractExtendedResultDecoder;
import org.forgerock.opendj.ldap.responses.ExtendedResult;
import org.forgerock.opendj.ldap.responses.ExtendedResultDecoder;

/**
 * Get connection ID extended request. This operation can be used to retrieve
 * the client connection ID.
 *
 * @see GetConnectionIDExtendedResult
 */
public final class GetConnectionIDExtendedRequest extends
        AbstractExtendedRequest<GetConnectionIDExtendedRequest, GetConnectionIDExtendedResult> {
    private static final class RequestDecoder implements
            ExtendedRequestDecoder<GetConnectionIDExtendedRequest, GetConnectionIDExtendedResult> {

        @Override
        public GetConnectionIDExtendedRequest decodeExtendedRequest(
                final ExtendedRequest<?> request, final DecodeOptions options)
                throws DecodeException {
            // TODO: Check the OID and that the value is not present.
            final GetConnectionIDExtendedRequest newRequest = new GetConnectionIDExtendedRequest();
            for (final Control control : request.getControls()) {
                newRequest.addControl(control);
            }
            return newRequest;

        }
    }

    private static final class ResultDecoder extends
            AbstractExtendedResultDecoder<GetConnectionIDExtendedResult> {
        @Override
        public GetConnectionIDExtendedResult newExtendedErrorResult(final ResultCode resultCode,
                final String matchedDN, final String diagnosticMessage) {
            if (!resultCode.isExceptional()) {
                // A successful response must contain a response name and
                // value.
                throw new IllegalArgumentException("No response name and value for result code "
                        + resultCode.intValue());
            }
            return GetConnectionIDExtendedResult.newResult(resultCode).setMatchedDN(matchedDN)
                    .setDiagnosticMessage(diagnosticMessage);
        }

        @Override
        public GetConnectionIDExtendedResult decodeExtendedResult(final ExtendedResult result,
                final DecodeOptions options) throws DecodeException {
            if (result instanceof GetConnectionIDExtendedResult) {
                return (GetConnectionIDExtendedResult) result;
            }

            final ResultCode resultCode = result.getResultCode();
            final GetConnectionIDExtendedResult newResult =
                    GetConnectionIDExtendedResult.newResult(resultCode)
                        .setMatchedDN(result.getMatchedDN())
                        .setDiagnosticMessage(result.getDiagnosticMessage());

            final ByteString responseValue = result.getValue();
            if (!resultCode.isExceptional() && responseValue == null) {
                throw DecodeException.error(LocalizableMessage.raw("Empty response value"));
            }
            if (responseValue != null) {
                try {
                    final ASN1Reader reader = ASN1.getReader(responseValue);
                    newResult.setConnectionID((int) reader.readInteger());
                } catch (final IOException e) {
                    throw DecodeException.error(LocalizableMessage
                            .raw("Error decoding response value"), e);
                }
            }
            for (final Control control : result.getControls()) {
                newResult.addControl(control);
            }
            return newResult;
        }
    }

    /**
     * The OID for the extended operation that can be used to get the client
     * connection ID. It will be both the request and response OID.
     */
    public static final String OID = "1.3.6.1.4.1.26027.1.6.2";

    /** Singleton. */
    private static final GetConnectionIDExtendedRequest INSTANCE =
            new GetConnectionIDExtendedRequest();

    /** A decoder which can be used to decode get connection ID extended operation requests. */
    public static final RequestDecoder REQUEST_DECODER = new RequestDecoder();

    /** No need to expose this. */
    private static final ResultDecoder RESULT_DECODER = new ResultDecoder();

    /**
     * Creates a new get connection ID extended request.
     *
     * @return The new get connection ID extended request.
     */
    public static GetConnectionIDExtendedRequest newRequest() {
        return INSTANCE;
    }

    /** Prevent instantiation. */
    private GetConnectionIDExtendedRequest() {
        // Nothing to do.
    }

    @Override
    public String getOID() {
        return OID;
    }

    @Override
    public ExtendedResultDecoder<GetConnectionIDExtendedResult> getResultDecoder() {
        return RESULT_DECODER;
    }

    @Override
    public ByteString getValue() {
        return null;
    }

    @Override
    public boolean hasValue() {
        return false;
    }

    @Override
    public String toString() {
        final StringBuilder builder = new StringBuilder();
        builder.append("GetConnectionIDExtendedRequest(requestName=");
        builder.append(getOID());
        builder.append(", controls=");
        builder.append(getControls());
        builder.append(")");
        return builder.toString();
    }
}