package org.apache.onami.configuration.variables;

 /*

  * 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 static java.lang.String.format;

 import static java.util.logging.Level.FINEST;

 import static java.util.logging.Logger.getLogger;

 import java.util.Map;

 import java.util.logging.Logger;

 /**

  * Abstract Appender implementation handling resolving context management.

  *

  * @since 6.2

  */

 abstract class AbstractAppender

     implements Appender

 {

     /** Logger */

     private static final Logger logger = getLogger( AbstractAppender.class.getName() );

     /** Original chunk to process by this appender */

     protected final String chunk;

     /**

      * Default constructor

      *

      * @param chunk The chunk this appender has to process.

      */

     protected AbstractAppender( String chunk )

     {

         this.chunk = chunk;

     }

     /**

      * Move provided context to current appender and call {@link #doAppend(StringBuilder, Map, Tree, Parser)} if no recursion has been detected.

      *

      * @param buffer

      * @param configuration

      * @param context

      */

     public final void append( StringBuilder buffer, Map<String, String> configuration, Tree<Appender> context )

     {

         // Create context if needed

         Tree<Appender> currentContext = context == null ? new Tree<Appender>( this ) : context.addLeaf( this );

         // Check recursion

         if ( currentContext.inAncestors( this ) )

         {

             // For the moment just log a warning, and stop the resolving by appending original chunk

             buffer.append( chunk );

             logger.warning( format( "Recursion detected within variable resolving:%n%s", currentContext.getRoot() ) );

         }

         // Process real appending

         else

         {

             doAppend( buffer, configuration, currentContext );

             // Dump some info on resolution if this is a root appender

             if ( currentContext.isRoot() && logger.isLoggable( FINEST ) )

             {

                 logger.finest( format( "Resolving variables:%n%s", currentContext ) );

             }

         }

     }

     /**

      * Begin resolving process with this appender against the provided configuration.

      */

     public String resolve( Map<String, String> configuration )

     {

         StringBuilder buffer = new StringBuilder();

         append( buffer, configuration, null );

         return buffer.toString();

     }

     /**

      * Append something to the provided buffer for the given configuration.<br>

      *

      * @param buffer

      * @param configuration

      * @param passed Resolving context, current element is the appender itself.

      */

     protected abstract void doAppend( StringBuilder buffer, Map<String, String> configuration, Tree<Appender> context );

     /**

      * Abstract to force subclasses to re-implement.

      */

     @Override

     public abstract boolean equals( Object obj );

     /**

      * Abstract to force subclasses to re-implement.

      */

     @Override

     public abstract int hashCode();

     /**

      * @return original chunk

      */

     @Override

     public final String toString()

     {

         return chunk;

     }

 }