/*

  * Copyright 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.config.transfer.filesystem;

 import java.io.BufferedOutputStream;

 import java.io.File;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.io.OutputStream;

 import java.util.Properties;

 import org.apache.commons.io.FileUtils;

 import org.apache.commons.io.IOUtils;

 import de.smartics.properties.api.config.domain.Property;

 import de.smartics.properties.api.config.domain.PropertyLocation;

 import de.smartics.properties.api.config.domain.PropertyProvider;

 import de.smartics.properties.api.config.domain.key.ConfigurationKey;

 import de.smartics.properties.api.config.transfer.PropertySink;

 import de.smartics.properties.api.config.transfer.TransferException;

 import de.smartics.properties.spi.config.domain.key.ConfigurationKeyContextManager;

 import de.smartics.util.io.FileFunction;

 import de.smartics.util.lang.Arg;

 /**

  * Writes properties to a folder.

  */

 public final class FileSystemPropertySink implements PropertySink

 {

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

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

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

   /**

    * The name of the folder the properties definitions are written to.

    */

   private final File targetFolder;

   /**

    * The format the property definition files will be written to.

    */

   private final PropertiesFormat outputFormat;

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

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

   /**

    * Convenience constructor to create native properties files.

    *

    * @param targetFolder the name of the folder the properties definitions are

    *          written to.

    */

   public FileSystemPropertySink(final File targetFolder)

   {

     this(targetFolder, PropertiesFormat.NATIVE);

   }

   /**

    * Default constructor.

    *

    * @param targetFolder the name of the folder the properties definitions are

    *          written to.

    * @param outputFormat the format the property definition files will be

    *          written to.

    * @throws NullPointerException if {@code targetFolder} or

    *           {@code outputFormat} is <code>null</code>.

    */

   public FileSystemPropertySink(final File targetFolder,

       final PropertiesFormat outputFormat) throws NullPointerException

   {

     this.targetFolder = Arg.checkNotNull("targetFolder", targetFolder);

     this.outputFormat = Arg.checkNotNull("outputFormat", outputFormat);

   }

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

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

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

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

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

   @Override

   public void clear() throws TransferException

   {

     try

     {

       FileUtils.cleanDirectory(targetFolder);

     }

     catch (final IOException e)

     {

       final ConfigurationKey<?> key =

           ConfigurationKeyContextManager.INSTANCE.context()

               .configurationKeyFactory().createDefaultKey();

       throw new TransferException(new TransferMessageBean(

           TransferFileCode.FAILED_TO_CLEAN, e, key, targetFolder));

     }

   }

   // TODO: Not yet transactional ...

   @Override

   public void write(final PropertyProvider provider) throws TransferException

   {

     final PropertyLocation location = provider.getSourceId();

     final ConfigurationKey<?> key = provider.getConfigurationKey();

     final Properties properties = createProperties(provider);

     writeProperties(key, location, properties);

   }

   private Properties createProperties(final PropertyProvider provider)

   {

     final Properties properties = new Properties();

     for (final Property property : provider.getProperties())

     {

       final String name = property.getName();

       final String value = property.getValue();

       properties.setProperty(name, value);

     }

     return properties;

   }

   private void writeProperties(final ConfigurationKey<?> key,

       final PropertyLocation location, final Properties properties)

   {

     // FIXME: translate location to a valid filename path

     final String path = location.getPath();

     final File propertiesFile = createFile(path);

     OutputStream out = null;

     try

     {

       final File parentDir = propertiesFile.getParentFile();

       FileFunction.provideDirectory(parentDir);

       out = new BufferedOutputStream(new FileOutputStream(propertiesFile));

       final String comments = key.toString();

       if (outputFormat == PropertiesFormat.XML)

       {

         properties.storeToXML(out, comments);

       }

       else

       {

         properties.store(out, comments);

       }

     }

     catch (final IOException e)

     {

       throw new TransferException(new TransferMessageBean(

           TransferFileCode.FAILED_TO_TRANSFER, e, key, targetFolder));

     }

     finally

     {

       IOUtils.closeQuietly(out);

     }

   }

   private File createFile(final String path)

   {

     final String adjustedPath = outputFormat.adjustPath(path);

     return new File(targetFolder, adjustedPath);

   }

   // TODO: Not yet transactional ...

   @Override

   public void write(final Iterable<PropertyProvider> providers)

     throws TransferException

   {

     for (final PropertyProvider provider : providers)

     {

       write(provider);

     }

   }

   /**

    * {@inheritDoc}

    * <p>

    * This is a no-op.

    * </p>

    */

   @Override

   public void close() throws TransferException

   {

   }

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

 }