/*******************************************************************************
*Copyright (c) 2009  Eucalyptus Systems, Inc.
* 
*  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, only version 3 of the License.
* 
* 
*  This file 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, see <http://www.gnu.org/licenses/>.
* 
*  Please contact Eucalyptus Systems, Inc., 130 Castilian
*  Dr., Goleta, CA 93101 USA or visit <http://www.eucalyptus.com/licenses/>
*  if you need additional information or have any questions.
* 
*  This file may incorporate work covered under the following copyright and
*  permission notice:
* 
*    Software License Agreement (BSD License)
* 
*    Copyright (c) 2008, Regents of the University of California
*    All rights reserved.
* 
*    Redistribution and use of this software in source and binary forms, with
*    or without modification, are permitted provided that the following
*    conditions are met:
* 
*      Redistributions of source code must retain the above copyright notice,
*      this list of conditions and the following disclaimer.
* 
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*      notice, this list of conditions and the following disclaimer in the
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*    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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*    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
*    PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
*    OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
*    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
*    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
*    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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*    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
*    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. USERS OF
*    THIS SOFTWARE ACKNOWLEDGE THE POSSIBLE PRESENCE OF OTHER OPEN SOURCE
*    LICENSED MATERIAL, COPYRIGHTED MATERIAL OR PATENTED MATERIAL IN THIS
*    SOFTWARE, AND IF ANY SUCH MATERIAL IS DISCOVERED THE PARTY DISCOVERING
*    IT MAY INFORM DR. RICH WOLSKI AT THE UNIVERSITY OF CALIFORNIA, SANTA
*    BARBARA WHO WILL THEN ASCERTAIN THE MOST APPROPRIATE REMEDY, WHICH IN
*    THE REGENTS’ DISCRETION MAY INCLUDE, WITHOUT LIMITATION, REPLACEMENT
*    OF THE CODE SO IDENTIFIED, LICENSING OF THE CODE SO IDENTIFIED, OR
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*******************************************************************************/
/*
 * Author: chris grzegorczyk <grze@eucalyptus.com>
 */
package com.eucalyptus.ws.util;

import java.util.ArrayList;
import java.util.List;

import org.apache.log4j.Logger;
import org.jboss.netty.handler.codec.http.HttpRequest;

import com.eucalyptus.records.EventType;
import com.eucalyptus.system.LogLevels;
import com.eucalyptus.ws.server.DuplicatePipelineException;
import com.eucalyptus.ws.server.FilteredPipeline;
import com.eucalyptus.ws.server.NoAcceptingPipelineException;

import com.eucalyptus.records.EventRecord;

public class PipelineRegistry {
  private static PipelineRegistry registry;
  private static Logger           LOG = Logger.getLogger( PipelineRegistry.class );

  public static PipelineRegistry getInstance( ) {
    synchronized ( PipelineRegistry.class ) {
      if ( PipelineRegistry.registry == null ) {
        PipelineRegistry.registry = new PipelineRegistry( );
      }
    }
    return PipelineRegistry.registry;
  }

  private final List<FilteredPipeline> pipelines = new ArrayList<FilteredPipeline>( );

  public void register( final FilteredPipeline pipeline ) {
    LOG.info( "-> Registering pipeline: " + pipeline.getPipelineName( ) );
    this.pipelines.add( pipeline );
  }

  public FilteredPipeline find( final HttpRequest request ) throws DuplicatePipelineException, NoAcceptingPipelineException {
    FilteredPipeline candidate = null;
    for ( FilteredPipeline f : this.pipelines) {
      if ( f.accepts( request ) ) {
        if( !LogLevels.DEBUG ) {
          return f;
        } else if ( candidate != null ) {
          EventRecord.here( this.getClass(), EventType.PIPELINE_DUPLICATE, f.getPipelineName( ), f.getClass( ).getSimpleName( ) ).trace( );
        } else {
          candidate = f;
        }
      }
    }
    if ( candidate == null ) { throw new NoAcceptingPipelineException( ); }
    return candidate;
  }


}