/*
    * 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.io.OutputStream;
  
  import org.apache.commons.configuration.ConfigurationException;
  import org.apache.commons.configuration.PropertiesConfiguration;
  
  import de.smartics.properties.api.core.domain.PropertyDescriptor;
  import de.smartics.properties.api.core.domain.PropertyExpression;
  import de.smartics.properties.report.app.ReportException;
  import de.smartics.properties.report.data.PropertyReportItem;
  import de.smartics.properties.report.data.PropertyReportSet;
  import de.smartics.util.lang.Arg;
  
  /**
   * Stores every report item in a property set.
   */
  public final class PropertiesPropertyReport extends AbstractPropertyReport
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    // --- members --------------------------------------------------------------
  
    /**
     * The current comment to prepend to the collected properties.
     */
    private String currentComment;
  
    /**
     * The currently collected properties.
     */
    private final PropertiesConfiguration currentProperties =
        new PropertiesConfiguration();
  
    /**
     * The stream to write to.
     */
    private final OutputStream output;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Constructor.
     *
     * @param output the stream to write to.
     * @see de.smartics.properties.reports.AbstractPropertyReport#AbstractPropertyReport()
     */
    public PropertiesPropertyReport(final OutputStream output)
    {
      this.output = Arg.checkNotNull("output", output);
    }
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    // --- get&set --------------------------------------------------------------
  
    // --- business -------------------------------------------------------------
  
    @Override
    public void handle(final PropertyReportSet reportSet) throws ReportException
    {
      flush(reportSet.getName());
  
      final StringBuilder buffer = new StringBuilder(256);
      buffer.append(reportSet.getName()).append('\n')
          .append(reportSet.getComment());
      currentComment = buffer.toString();
    }
  
    private void flush(final String name) throws ReportException
    {
      if (!currentProperties.isEmpty())
      {
        try
        {
          currentProperties.setHeader(currentComment);
         currentProperties.save(output, "ISO8859-1");
       }
       catch (final ConfigurationException e)
       {
         final String message =
             name != null ? "Cannot write report set '" + name + "'."
                 : "Cannot flush.";
         throw new ReportException(message, e);
       }
 
       currentProperties.clear();
     }
   }
 
   @Override
   public void handle(final PropertyReportItem item) throws ReportException
   {
     super.handle(item);
 
     final PropertyDescriptor descriptor = item.getDescriptor();
     final String key = descriptor.getKey().toString();
 
     final PropertyExpression expression = descriptor.getDefaultExpression();
     final String value =
         expression != null && expression.getExpression() != null ? expression
             .getExpression() : "";
 
     currentProperties.setProperty(key, value);
   }
 
   /**
    * Flushes the latest report set and items.
    */
   public void flush()
   {
     flush(null);
   }
 
   // --- object basics --------------------------------------------------------
 
 }