/*

  * 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.spi.core.metadata.projectdoc;

 import static de.smartics.util.lang.StaticAnalysis.UNCHECKED;

 import java.io.BufferedInputStream;

 import java.io.IOException;

 import java.io.InputStream;

 import java.util.List;

 import java.util.Locale;

 import org.apache.commons.io.IOUtils;

 import org.jdom.Document;

 import org.jdom.Element;

 import org.jdom.JDOMException;

 import org.jdom.Namespace;

 import org.jdom.input.SAXBuilder;

 import org.jdom.output.XMLOutputter;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 import de.smartics.properties.api.core.domain.DocumentMetaData;

 import de.smartics.properties.api.core.domain.PropertiesContext;

 import de.smartics.properties.api.core.domain.PropertyDescriptor;

 import de.smartics.properties.spi.core.metadata.projectdoc.ProjectdocAnnotationCollector.Defaults;

 import de.smartics.util.lang.Arguments;

 import de.smartics.util.lang.NullArgumentException;

 /**

  * Parses projectdoc information from property XML descriptors.

  */

 public final class ProjectdocMetaDataParser

 {

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

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

   /**

    * Reference to the logger for this class.

    */

   private static final Logger LOG = LoggerFactory

       .getLogger(ProjectdocMetaDataParser.class);

   /**

    * The namespace of the XML files this parser can parse.

    */

   private static final Namespace PROPERTY_NS =

       Namespace

           .getNamespace("http://www.smartics.de/schema/projectdoc/doctype/property/1");

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

   /**

    * The properties context to fetch information from the META-INF folder.

    */

   private final PropertiesContext context;

   /**

    * The metadata defaults to use.

    */

   private final Defaults defaults;

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

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

   /**

    * Default constructor without defaults.

    *

    * @param context the properties context to fetch information from the

    *          META-INF folder.

    * @throws NullArgumentException if {@code context} is <code>null</code>.

    */

   public ProjectdocMetaDataParser(final PropertiesContext context)

     throws NullArgumentException

   {

     this(context, null);

   }

   /**

    * Default constructor.

    *

    * @param context the properties context to fetch information from the

    *          META-INF folder.

    * @param defaults the metadata defaults to use.

    * @throws NullArgumentException if {@code context} is <code>null</code>.

    */

   public ProjectdocMetaDataParser(final PropertiesContext context,

       final Defaults defaults) throws NullArgumentException

   {

     Arguments.checkNotNull("context", context);

     this.context = context;

     this.defaults = defaults;

   }

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

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

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

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

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

   /**

    * Parses the comments for the given descriptor.

    *

    * @param descriptor the descriptor whose comments are requested to be parsed.

    * @param locale the locale to select the comments.

    * @return the comments for the given locale or the default comments, if the

    *         locale is not supported.

    */

   public DocumentMetaData parse(final PropertyDescriptor descriptor,

       final Locale locale)

   {

     final String path = context.createMetaInfPath(descriptor, locale);

     final ClassLoader loader = descriptor.getClass().getClassLoader(); // NOPMD

     InputStream input = null;

     try

     {

       final InputStream resource = loader.getResourceAsStream(path);

       if (resource != null)

       {

         input = new BufferedInputStream(resource);

         final DocumentMetaData metaData = parse(path, input);

         return metaData;

       }

       else

       {

         LOG.warn("No meta data for property descriptor '{}' found: {}",

             descriptor, path);

       }

     }

     catch (final MetaDataException e)

     {

       LOG.warn("Cannot parse meta data for property descriptor '{}': {}",

           descriptor, e);

     }

     finally

     {

       IOUtils.closeQuietly(input);

     }

     return null;

   }

   private DocumentMetaData parse(final String systemId, final InputStream input)

     throws MetaDataException

   {

     try

     {

       final SAXBuilder parser = new SAXBuilder();

       final Document document = parser.build(input, systemId);

       final ProjectdocMetaData metaData = new ProjectdocMetaData();

       final Element rootNode = document.getRootElement();

       addIdInfo(metaData, rootNode);

       addFiling(metaData, rootNode);

       addDescription(metaData, rootNode);

       return metaData;

     }

     catch (final JDOMException e)

     {

       throw new MetaDataException(systemId, e);

     }

     catch (final IOException e)

     {

       throw new MetaDataException(systemId, e);

     }

   }

   private void addIdInfo(final ProjectdocMetaData metaData,

       final Element rootNode)

   {

     if (defaults != null)

     {

       metaData.setName(defaults.getName());

       metaData.setSpace(defaults.getSpace());

       metaData.setTitle(defaults.getTitle());

     }

     final Element identification =

         rootNode.getChild("identification", PROPERTY_NS);

     if (identification != null)

     {

       final String space =

           identification.getChildTextNormalize("space", PROPERTY_NS);

       metaData.setSpace(space);

       final String title =

           identification.getChildTextNormalize("title", PROPERTY_NS);

       metaData.setTitle(title);

     }

     final String name = rootNode.getChildTextNormalize("name", PROPERTY_NS);

     metaData.setName(name);

   }

   private void addFiling(final ProjectdocMetaData metaData,

       final Element rootNode)

   {

     final Element filing = rootNode.getChild("filing", PROPERTY_NS);

     if (filing != null)

     {

       addParents(metaData, filing);

       addCategories(metaData, filing);

       addTags(metaData, filing);

       setSortKey(metaData, filing);

     }

   }

   @SuppressWarnings(UNCHECKED)

   private void addParents(final ProjectdocMetaData metaData,

       final Element filing)

   {

     final Element parentsElement = filing.getChild("parents", PROPERTY_NS);

     if (parentsElement != null)

     {

       final List<Element> parents =

           parentsElement.getChildren("parent", PROPERTY_NS);

       for (final Element parent : parents)

       {

         final String parentName = parent.getTextNormalize();

         metaData.addParent(parentName);

       }

     }

   }

   @SuppressWarnings(UNCHECKED)

   private void addCategories(final ProjectdocMetaData metaData,

       final Element filing)

   {

     final Element categoriesElement =

         filing.getChild("categories", PROPERTY_NS);

     if (categoriesElement != null)

     {

       final List<Element> categories =

           categoriesElement.getChildren("category", PROPERTY_NS);

       for (final Element category : categories)

       {

         final String categoryName = category.getTextNormalize();

         metaData.addCategory(categoryName);

       }

     }

   }

   @SuppressWarnings(UNCHECKED)

   private void addTags(final ProjectdocMetaData metaData, final Element filing)

   {

     final Element tagsElement = filing.getChild("tags", PROPERTY_NS);

     if (tagsElement != null)

     {

       final List<Element> tags = tagsElement.getChildren("tag", PROPERTY_NS);

       for (final Element tag : tags)

       {

         final String tagName = tag.getTextNormalize();

         metaData.addTag(tagName);

       }

     }

   }

   private void setSortKey(final ProjectdocMetaData metaData,

       final Element filing)

   {

     final String sortKey = filing.getChildTextNormalize("sortKey", PROPERTY_NS);

     metaData.setSortKey(sortKey);

   }

   @SuppressWarnings(UNCHECKED)

   private void addDescription(final ProjectdocMetaData metaData,

       final Element rootNode)

   {

     final Element description = rootNode.getChild("description", PROPERTY_NS);

     if (description != null)

     {

       final Element audienceElement =

           description.getChild("audience", PROPERTY_NS);

       if (audienceElement != null)

       {

         final List<Element> members =

             audienceElement.getChildren("member", PROPERTY_NS);

         for (final Element member : members)

         {

           final String memberName = member.getTextNormalize();

           metaData.addAudience(memberName);

         }

       }

       final Element shortDescriptionElement =

           description.getChild("shortDescription", PROPERTY_NS);

       final String shortDescription = toString(shortDescriptionElement);

       metaData.setShortDescription(shortDescription);

       final Element summaryElement =

           description.getChild("summary", PROPERTY_NS);

       final String summary = toString(summaryElement);

       metaData.setSummary(summary);

       final Element notesElement = description.getChild("notes", PROPERTY_NS);

       final String notes = toString(notesElement);

       metaData.addNote(notes);

     }

   }

   private static String toString(final Element element)

   {

     final XMLOutputter outp = new XMLOutputter();

     final StringBuilder buffer = new StringBuilder(1024);

     final List<?> children = element.getContent();

     final String string = outp.outputString(children);

     buffer.append(string);

     return buffer.toString().trim();

   }

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

 }