/*
    * Copyright 2006-2012 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.maven.plugin.buildmetadata.io;
  
  import java.io.BufferedInputStream;
  import java.io.BufferedOutputStream;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.Properties;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.logging.Log;
  import org.apache.maven.project.MavenProject;
  
  import de.smartics.maven.plugin.buildmetadata.common.MojoUtils;
  import de.smartics.maven.plugin.buildmetadata.common.SortedProperties;
  
  /**
   * Helper to handle the build meta data properties file.
   *
   * @author <a href="mailto:robert.reiner@smartics.de">Robert Reiner</a>
   * @version $Revision:591 $
   */
  public final class BuildPropertiesFileHelper
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    // --- members --------------------------------------------------------------
  
    /**
     * The logger to use.
     */
    private final Log log;
  
    /**
     * The file to write to.
     */
    private final File propertiesOutputFile;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Default constructor.
     *
     * @param log the logger to use.
     * @param propertiesOutputFile the file to write to.
     */
    public BuildPropertiesFileHelper(final Log log,
        final File propertiesOutputFile)
    {
      this.log = log;
      this.propertiesOutputFile = propertiesOutputFile;
    }
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    // --- get&set --------------------------------------------------------------
  
    // --- business -------------------------------------------------------------
  
    /**
     * Writes the build meta data properties to the target file.
     *
     * @param buildMetaDataProperties the properties to write.
     * @return the reference to the written file.
     * @throws MojoExecutionException on any problem encountered while writing the
     *           properties.
     */
    public File writePropertiesFile(final Properties buildMetaDataProperties)
      throws MojoExecutionException
    {
      final File buildMetaDataFile =
         createBuildMetaDataFile(propertiesOutputFile);
     if (log.isInfoEnabled())
     {
       log.info("Writing properties '" + buildMetaDataFile.getAbsolutePath()
                + "'...");
     }
 
     OutputStream out = null;
     try
     {
       out = new BufferedOutputStream(new FileOutputStream(buildMetaDataFile));
       final String comments = "Created by maven-buildmetadata-plugin.";
       final Properties sortedBuildMetaDataProperties =
           SortedProperties.createSorted(buildMetaDataProperties);
       sortedBuildMetaDataProperties.store(out, comments);
     }
     catch (final FileNotFoundException e)
     {
       final String message =
           "Cannot find file '" + buildMetaDataFile
               + "' to write properties to.";
       throw MojoUtils.createException(log, e, message);
     }
     catch (final IOException e)
     {
       final String message =
           "Cannot write properties to file '" + buildMetaDataFile + "'.";
       throw MojoUtils.createException(log, e, message);
     }
     finally
     {
       IOUtils.closeQuietly(out);
     }
 
     return buildMetaDataFile;
   }
 
   /**
    * Creates the properties file for the build meta data. If the directory to
    * place it in is not present, it will be created.
    *
    * @return the file to write the build properties to.
    * @throws MojoExecutionException if the output directory is not present and
    *           cannot be created.
    */
   private File createBuildMetaDataFile(final File propertiesOutputFile)
     throws MojoExecutionException
   {
     final File outputDirectory = propertiesOutputFile.getParentFile();
     if (!outputDirectory.exists())
     {
       final boolean created = outputDirectory.mkdirs();
       if (!created)
       {
         throw new MojoExecutionException("Cannot create output directory '"
                                          + outputDirectory + "'.");
       }
     }
     return propertiesOutputFile;
   }
 
   /**
    * Reads the build properties file from stream. The properties file is passed
    * to this instance via the {@link #BuildPropertiesFileHelper(Log, File)
    * constructor} {@code propertiesOutputFile}.
    *
    * @param buildMetaDataProperties the properties instance to append the read
    *          properties to.
    * @throws MojoExecutionException if the properties cannot be read.
    */
   public void readBuildPropertiesFile(final Properties buildMetaDataProperties)
     throws MojoExecutionException
   {
     InputStream inStream = null;
     try
     {
       inStream =
           new BufferedInputStream(new FileInputStream(propertiesOutputFile));
       buildMetaDataProperties.load(inStream);
     }
     catch (final IOException e)
     {
       throw new MojoExecutionException(
           "Cannot read provided properties file: "
               + propertiesOutputFile.getAbsolutePath(), e);
     }
     finally
     {
       IOUtils.closeQuietly(inStream);
     }
   }
 
   /**
    * Fetches the project properties and if <code>null</code> returns a new empty
    * properties instance that is associated with the project.
    *
    * @param project the project whose properties are requested.
    * @return the properties of the project.
    */
   public Properties getProjectProperties(final MavenProject project)
   {
     Properties projectProperties = project.getProperties();
     if (projectProperties == null)
     {
       projectProperties = new Properties();
       project.getModel().setProperties(projectProperties);
     }
 
     return projectProperties;
   }
 
   // --- object basics --------------------------------------------------------
 
 }