/*

  * Copyright 2007-2013 smartics, Kronseder & Reiner GmbH

  *

  * Licensed 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.

  */

 package de.smartics.exceptions.i18n;

 import java.io.Serializable;

 import java.util.ArrayList;

 import java.util.Collections;

 import java.util.List;

 import java.util.Locale;

 import org.apache.commons.lang.StringUtils;

 import de.smartics.exceptions.i18n.message.MessageType;

 import de.smartics.exceptions.i18n.message.Messages;

 /**

  * Stores the message information of the causes. The exception whose cause trail

  * this instance is, is <strong>not</strong> part of the cause trail. This makes

  * it possible to render all messages without need to skip the first one that is

  * usually rendered otherwise.

  */

 public final class CauseTrailMessages implements Serializable

 {

   // ********************************* Fields *********************************

   // --- constants ------------------------------------------------------------

   /**

    * The class version identifier.

    */

   private static final long serialVersionUID = 1L;

   // --- members --------------------------------------------------------------

   /**

    * The trail of messages to the root.

    */

   private final List<Messages> trail = new ArrayList<Messages>();

   // ****************************** Initializer *******************************

   // ****************************** Constructors ******************************

   /**

    * Convenience constructor using the default locale.

    *

    * @param cause the cause to the exception this is the cause trail instance

    *          for.

    */

   public CauseTrailMessages(final Throwable cause)

   {

     this(Locale.getDefault(), cause);

   }

   /**

    * Default constructor.

    *

    * @param locale the locale for which the message is requested.

    * @param cause the cause to the exception this is the cause trail instance

    *          for.

    */

   public CauseTrailMessages(final Locale locale, final Throwable cause)

   {

     initCauseTrail(locale, cause);

   }

   // ****************************** Inner Classes *****************************

   // ********************************* Methods ********************************

   // --- init -----------------------------------------------------------------

   private void initCauseTrail(final Locale locale, final Throwable cause)

   {

     Throwable current = cause;

     while (current != null)

     {

       if (current instanceof LocalizedException)

       {

         final LocalizedException localizedException =

             (LocalizedException) current;

         final Messages messages = localizedException.createMessages(locale);

         trail.add(messages);

         final CauseTrailMessages causeTrail =

             localizedException.getCauseTrail(locale);

         trail.addAll(causeTrail.trail);

         current = null;

       }

       else

       {

         final Messages messages = createNonSmarticsExceptionsMessages(current);

         trail.add(messages);

         current = current.getCause();

       }

     }

   }

   private Messages createNonSmarticsExceptionsMessages(final Throwable current)

   {

     final String text = current.getLocalizedMessage();

     return new Messages.Builder()

         .put(MessageType.TITLE, current.getClass().getName())

         .put(MessageType.SUMMARY, text != null ? text : "n/a").build();

   }

   // --- get&set --------------------------------------------------------------

   /**

    * Returns the trail of messages to the root.

    *

    * @return the trail of messages to the root.

    */

   public List<Messages> getTrail()

   {

     return Collections.unmodifiableList(trail);

   }

   // --- business -------------------------------------------------------------

   // --- object basics --------------------------------------------------------

   @Override

   public String toString()

   {

     final StringBuilder buffer = new StringBuilder(trail.size() * 256);

     int i = 0;

     for (final Messages messages : trail)

     {

       final String prefix = StringUtils.repeat(" ", i++);

       for (final MessageType type : MessageType.values())

       {

         final String message = messages.getMessage(type);

         if (message != null)

         {

           buffer.append(prefix).append(type).append('=').append(message)

               .append('\n');

         }

       }

     }

     return StringUtils.chomp(buffer.toString());

   }

 }