package org.apache.maven.usability.diagnostics;

 /*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you under the Apache License, Version 2.0 (the

  * "License"); you may not use this file except in compliance

  * with the License.  You may obtain a copy of the License at

  *

  *  http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an

  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

  * KIND, either express or implied.  See the License for the

  * specific language governing permissions and limitations

  * under the License.

  */

 import org.codehaus.plexus.PlexusConstants;

 import org.codehaus.plexus.PlexusContainer;

 import org.codehaus.plexus.component.repository.exception.ComponentLifecycleException;

 import org.codehaus.plexus.component.repository.exception.ComponentLookupException;

 import org.codehaus.plexus.context.Context;

 import org.codehaus.plexus.context.ContextException;

 import org.codehaus.plexus.logging.AbstractLogEnabled;

 import org.codehaus.plexus.personality.plexus.lifecycle.phase.Contextualizable;

 import java.util.Iterator;

 import java.util.List;

 public class ErrorDiagnostics

     extends AbstractLogEnabled

     implements Contextualizable

 {

     public static final String ROLE = ErrorDiagnostics.class.getName();

     private PlexusContainer container;

     private List errorDiagnosers;

     public void setErrorDiagnosers( List errorDiagnosers )

     {

         this.errorDiagnosers = errorDiagnosers;

     }

     public String diagnose( Throwable error )

     {

         List diags = errorDiagnosers;

         boolean releaseDiags = false;

         boolean errorProcessed = false;

         String message = null;

         try

         {

             if ( diags == null )

             {

                 releaseDiags = true;

                 try

                 {

                     diags = container.lookupList( ErrorDiagnoser.ROLE );

                 }

                 catch ( ComponentLookupException e )

                 {

                     getLogger().error( "Failed to lookup the list of error diagnosers.", e );

                 }

             }

             if ( diags != null )

             {

                 for ( Iterator it = diags.iterator(); it.hasNext(); )

                 {

                     ErrorDiagnoser diagnoser = (ErrorDiagnoser) it.next();

                     if ( diagnoser.canDiagnose( error ) )

                     {

                         errorProcessed = true;

                         message = diagnoser.diagnose( error );

                         break;

                     }

                 }

             }

         }

         finally

         {

             if ( releaseDiags && diags != null )

             {

                 try

                 {

                     container.releaseAll( diags );

                 }

                 catch ( ComponentLifecycleException e )

                 {

                     getLogger().debug( "Failed to release error diagnoser list.", e );

                 }

             }

             if ( !errorProcessed )

             {

                 message = new PuntErrorDiagnoser().diagnose( error );

             }

         }

         return message;

     }

     public void contextualize( Context context )

         throws ContextException

     {

         this.container = (PlexusContainer) context.get( PlexusConstants.PLEXUS_KEY );

     }

     private static class PuntErrorDiagnoser

         implements ErrorDiagnoser

     {

         public boolean canDiagnose( Throwable error )

         {

             return true;

         }

         public String diagnose( Throwable error )

         {

             StringBuffer message = new StringBuffer();

             message.append( error.getMessage() );

             DiagnosisUtils.appendRootCauseIfPresentAndUnique( error, message, false );

             return message.toString();

         }

     }

 }