/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
 * or http://forgerock.org/license/CDDLv1.0.html.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at legal-notices/CDDLv1_0.txt.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information:
 *      Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 *
 *      Copyright 2015 ForgeRock AS
 */
package org.opends.server.protocols.http;

import org.forgerock.http.Filter;
import org.forgerock.http.Handler;
import org.forgerock.http.header.MalformedHeaderException;
import org.forgerock.http.header.TransactionIdHeader;
import org.forgerock.http.protocol.Headers;
import org.forgerock.http.protocol.Request;
import org.forgerock.http.protocol.Response;
import org.forgerock.i18n.slf4j.LocalizedLogger;
import org.forgerock.services.TransactionId;
import org.forgerock.services.context.Context;
import org.forgerock.services.context.TransactionIdContext;
import org.forgerock.util.promise.NeverThrowsException;
import org.forgerock.util.promise.Promise;
import org.opends.server.core.ServerContext;

/**
 * This filter is responsible for creating a {@link TransactionIdContext} in the
 * context's chain.
 * <p>
 * This class is a copy of org.forgerock.http.filter.TransactionIdInboundFilter
 * in CHF, modified to not use a system property to indicate if transaction id
 * is trusted. Instead, it relies on DJ configuration to allow for runtime
 * modification It would be better if TransactionIdInboundFilter class could be
 * modified to be more generic and then usable by DJ, but it remains to be done.
 */
class CommonAuditTransactionIdFilter implements Filter
{
  private static final LocalizedLogger logger = LocalizedLogger.getLoggerForThisClass();

  private final ServerContext serverContext;

  CommonAuditTransactionIdFilter(ServerContext serverContext)
  {
    this.serverContext = serverContext;
  }

  @Override
  public Promise<Response, NeverThrowsException> filter(Context context, Request request, Handler next)
  {
    final TransactionId transactionId = serverContext.getCommonAudit().shouldTrustTransactionIds() ?
        createTransactionId(request.getHeaders()) : new TransactionId();
    final Context newContext = new TransactionIdContext(context, transactionId);
    return next.handle(newContext, request);
  }

  private TransactionId createTransactionId(Headers headers)
  {
    try
    {
      TransactionIdHeader txHeader = headers.get(TransactionIdHeader.class);
      return txHeader == null ? new TransactionId() : txHeader.getTransactionId();
    }
    catch (MalformedHeaderException ex)
    {
      logger.trace("The TransactionId header is malformed.", ex);
      return new TransactionId();
    }
  }
}