/*
    * Copyright 2012-2013 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.properties.reports;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  import javax.annotation.concurrent.NotThreadSafe;
  
  import com.google.common.collect.ArrayListMultimap;
  
  import de.smartics.properties.api.core.context.alias.AliasException;
  import de.smartics.properties.api.core.context.alias.AliasTraverser;
  import de.smartics.properties.api.core.context.alias.PropertyAliasMapping;
  import de.smartics.properties.api.core.domain.SourceInfo;
  import de.smartics.properties.report.app.ReportException;
  import de.smartics.properties.report.data.PropertyReport;
  import de.smartics.properties.report.data.PropertyReportItem;
  import de.smartics.properties.report.data.ReportProblem;
  
  /**
   * Writes each report to a file.
   */
  @NotThreadSafe
  public abstract class AbstractPropertyReport implements PropertyReport
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    // --- members --------------------------------------------------------------
  
    /**
     * The list of problems encountered while parsing sources and fetching report
     * information.
     */
    private final List<ReportProblem> problems = new ArrayList<ReportProblem>();
  
    /**
     * The map of aliases to property resources.
     */
    private final PropertyAliasMapping aliasMapping = new PropertyAliasMapping();
  
    /**
     * Map to recognize unique key constraint violations.
     */
    private final ArrayListMultimap<String, PropertyReportItem> keyUniquenessMap =
        ArrayListMultimap.create();
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Default constructor.
     */
    protected AbstractPropertyReport()
    {
    }
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    // --- get&set --------------------------------------------------------------
  
    /**
     * {@inheritDoc}
     *
     * @see de.smartics.properties.report.data.PropertyReport#getProblems()
     */
    public final List<ReportProblem> getProblems()
    {
      return Collections.unmodifiableList(problems);
    }
  
    // --- business -------------------------------------------------------------
  
    /**
     * {@inheritDoc}
     *
     * @see de.smartics.properties.report.data.PropertyReport#addProblem(de.smartics.properties.report.data.ReportProblem)
     */
   @Override
   public final void addProblem(final ReportProblem problem)
   {
     problems.add(problem);
   }
 
   /**
    * {@inheritDoc}
    *
    * @see de.smartics.properties.report.data.PropertyReport#hasProblems()
    */
   public final boolean hasProblems()
   {
     return !problems.isEmpty();
   }
 
   /**
    * {@inheritDoc}
    *
    * @see de.smartics.properties.report.data.PropertyReport#traverseAliases(de.smartics.properties.api.core.context.alias.AliasTraverser)
    */
   @Override
   public final void traverseAliases(final AliasTraverser traverser)
   {
     aliasMapping.traverse(traverser);
   }
 
   /**
    * {@inheritDoc}
    * <p>
    * Registers a report item to manage the alias mapping and check for
    * uniqueness constraint violations.
    * </p>
    *
    * @see de.smartics.properties.report.data.PropertyReport#handle(de.smartics.properties.report.data.PropertyReportItem)
    */
   // CHECKSTYLE:OFF Method can be overridden by sub classes.
   @Override
   public void handle(final PropertyReportItem item) throws ReportException
   // CHECKSTYLE:ON
   {
     register(item);
   }
 
   /**
    * Registers a report item to manage the alias mapping and check for
    * uniqueness constraint violations.
    *
    * @param item the report item to manage.
    */
   protected final void register(final PropertyReportItem item)
   {
     final String name = item.getName();
 
     checkForUniqueness(item, name);
 
     registerAlias(item, name);
   }
 
   private void checkForUniqueness(final PropertyReportItem item,
       final String name)
   {
     keyUniquenessMap.put(name, item);
     final List<PropertyReportItem> items = keyUniquenessMap.get(name);
     if (items.size() > 1)
     {
       final StringBuilder buffer = new StringBuilder(1024);
       buffer.append("Duplicate key '" + name + "' found:");
       for (final PropertyReportItem duplicate : items)
       {
         buffer.append("\n -> ")
             .append(duplicate.getSourceInfo().getElementId()).append('/')
             .append(duplicate.getDescriptor().getKey());
       }
       final String message = buffer.toString();
       final ReportProblem problem = new ReportProblem(message);
       addProblem(problem);
     }
   }
 
   private void registerAlias(final PropertyReportItem item, final String name)
   {
     // The element ID is easily accessible if the class or source code is
     // parsed.
     final SourceInfo sourceInfo = item.getSourceInfo();
     if (sourceInfo != null)
     {
       final String elementId = sourceInfo.getElementId();
       try
       {
         aliasMapping.add(elementId, name);
       }
       catch (final AliasException e)
       {
         addProblem(new ReportProblem("Cannot register alias '" + elementId
                                      + "'.", e));
       }
     }
   }
 
   // --- object basics --------------------------------------------------------
 
 }