/*
 * 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 2015 ForgeRock AS.
 */
package com.forgerock.opendj.ldap.controls;

import static com.forgerock.opendj.ldap.CoreMessages.*;

import org.forgerock.opendj.ldap.ByteString;
import org.forgerock.opendj.ldap.DecodeException;
import org.forgerock.opendj.ldap.DecodeOptions;
import org.forgerock.opendj.ldap.controls.Control;
import org.forgerock.opendj.ldap.controls.ControlDecoder;
import org.forgerock.util.Reject;

/**
 * Control to provide a transaction ID.
 * <p>
 * The transaction ID is related to Common Audit : it is used for tracking the processing of a user-interaction as it
 * passes through the Forgerock stack
 * <p>
 * The control's value is the UTF-8 encoding of the transaction ID.
 */
public final class TransactionIdControl implements Control {

    /** OID for this control. */
    public static final String OID = "1.3.6.1.4.1.36733.2.1.5.1";

    /** A decoder which can be used for decoding the simple paged results control. */
    public static final ControlDecoder<TransactionIdControl> DECODER = new ControlDecoder<TransactionIdControl>() {

        @Override
        public TransactionIdControl decodeControl(final Control control, final DecodeOptions options)
                throws DecodeException {
            Reject.ifNull(control);

            if (control instanceof TransactionIdControl) {
                return (TransactionIdControl) control;
            }

            if (!control.getOID().equals(OID)) {
                throw DecodeException.error(ERR_TRANSACTION_ID_CONTROL_BAD_OID.get(control.getOID(), OID));
            }

            if (!control.hasValue()) {
                // The control must always have a value.
                throw DecodeException.error(ERR_TRANSACTION_ID_CONTROL_DECODE_NULL.get());
            }

            return new TransactionIdControl(control.getValue().toString());
        }

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

    /**
     * Creates a new transactionId control.
     *
     * @param transactionId
     *            The transaction id to provide through this control.
     * @return The new control.
     * @throws NullPointerException
     *             If {@code transactionId} was {@code null}.
     */
    public static TransactionIdControl newControl(final String transactionId) {
        Reject.ifNull(transactionId);
        return new TransactionIdControl(transactionId);
    }

    /** The control value transactionId element. */
    private final String transactionId;

    private TransactionIdControl(final String transactionId) {
        this.transactionId = transactionId;
    }

    /**
     * Returns the transaction id.
     *
     * @return The transaction id.
     */
    public String getTransactionId() {
        return transactionId;
    }

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

    @Override
    public ByteString getValue() {
        return ByteString.valueOfUtf8(transactionId);
    }

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

    @Override
    public boolean isCritical() {
        // This control is never critical.
        return false;
    }

    @Override
    public String toString() {
        final StringBuilder builder = new StringBuilder();
        builder.append("TransactionIdControl(oid=");
        builder.append(getOID());
        builder.append(", transactionId=");
        builder.append(transactionId);
        builder.append(")");
        return builder.toString();
    }
}