PropertyMetaDataDefaults

/*
 * 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;

import java.lang.reflect.Method;

import org.apache.commons.lang.StringUtils;

import de.smartics.projectdoc.annotations.Document;
import de.smartics.properties.api.core.annotations.PropertyKeyName;
import de.smartics.properties.api.core.annotations.PropertySet;
import de.smartics.properties.spi.core.metadata.projectdoc.ProjectdocAnnotationCollector.Defaults;
import de.smartics.util.lang.Arg;

/**
 * Implementation to provide defaults from the project set annotation.
 */
public final class PropertyMetaDataDefaults implements Defaults
{
  // ******************************** Fields ********************************

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

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

  /**
   * The default title.
   */
  private final String title;

  /**
   * The default name.
   */
  private final String name;

  /**
   * The default space.
   */
  private final String space;

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

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

  /**
   * Default constructor using the declaring type. The default lack the method
   * name specifics.
   *
   * @param type the type to extract default values for title, name and space.
   * @throws NullPointerException if {@code type} is <code>null</code>.
   */
  public PropertyMetaDataDefaults(final Class<?> type)
    throws NullPointerException
  {
    this.space = createSpace(type);
    final PropertySet annotation = type.getAnnotation(PropertySet.class);
    this.title = annotation != null ? annotation.value() : type.getSimpleName();
    this.name = this.title;
  }

  /**
   * Default constructor using the declaring and method type.
   *
   * @param type the type to extract default values for title, name and space.
   * @param propertyMethod the method to check for a property set annotation
   *          that overrides the one of the type.
   * @throws NullPointerException if {@code type} is <code>null</code>.
   */
  public PropertyMetaDataDefaults(final Class<?> type,
      final Method propertyMethod) throws NullPointerException
  {
    this.space = createSpace(type);
    this.title = determineTitle(type, propertyMethod);
    this.name = determineName(type, propertyMethod);
  }

  /**
   * Default constructor using the method and adding the name of the method.
   *
   * @param propertyMethod the method to derive default values.
   */
  public PropertyMetaDataDefaults(final Method propertyMethod)
  {
    final Class<?> type = propertyMethod.getDeclaringClass();
    this.space = createSpace(type);
    this.title = determinePropertyTitle(type, propertyMethod);
    this.name = determinePropertyName(type, propertyMethod);
  }

  private PropertyMetaDataDefaults(final String space, final String name,
      final String title) throws NullPointerException
  {
    this.space = Arg.checkNotBlank("space", space);
    this.name = name;
    this.title = title;
  }

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

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

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

  private static String createSpace(final Class<?> type)
  {
    return "property:" + type.getName();
  }

  private static String determineTitle(final Class<?> type,
      final Method propertyMethod)
  {
    final Document document =
        determineDocumentTitleAnnotation(type, propertyMethod);
    final String title;
    if (document != null && document.title() != null)
    {
      title = document.title();
    }
    else
    {
      final PropertySet annotation =
          determinePropertySetAnnotation(type, propertyMethod);
      title = annotation != null ? annotation.value() : type.getSimpleName();
    }
    return title;
  }

  private static String determinePropertyTitle(final Class<?> type,
      final Method propertyMethod)
  {
    final Document document =
        determineDocumentTitleAnnotation(type, propertyMethod);
    final String prefix;
    if (document != null && document.title() != null)
    {
      prefix = document.title();
    }
    else
    {
      final PropertySet annotation =
          determinePropertySetAnnotation(type, propertyMethod);
      prefix = annotation != null ? annotation.value() : null;
    }

    final String property;
    final PropertyKeyName keyAnnotation =
        propertyMethod.getAnnotation(PropertyKeyName.class);
    if (keyAnnotation != null && keyAnnotation.value() != null)
    {
      property = keyAnnotation.value();
    }
    else
    {
      property = propertyMethod.getName();
    }

    final String title = prefix != null ? prefix + '.' + property : property;
    return title;
  }

  private static String determineName(final Class<?> type,
      final Method propertyMethod)
  {
    final Document document =
        determineDocumentNameAnnotation(type, propertyMethod);
    final String title;
    if (document != null && document.name() != null)
    {
      title = document.title();
    }
    else
    {
      final PropertySet annotation =
          determinePropertySetAnnotation(type, propertyMethod);
      title = annotation != null ? annotation.value() : type.getSimpleName();
    }
    return title;
  }

  private static String determinePropertyName(final Class<?> type,
      final Method propertyMethod)
  {
    final Document document =
        determineDocumentNameAnnotation(type, propertyMethod);
    final String prefix;
    if (document != null && document.name() != null)
    {
      prefix = document.name();
    }
    else
    {
      final PropertySet annotation =
          determinePropertySetAnnotation(type, propertyMethod);
      prefix = annotation != null ? annotation.value() : null;
    }

    final String property = propertyMethod.getName();

    final String name =
        StringUtils.isNotBlank(prefix) ? prefix + '.' + property : property;
    return name;
  }

  private static PropertySet determinePropertySetAnnotation(
      final Class<?> type, final Method propertyMethod)
  {
    PropertySet annotation = propertyMethod.getAnnotation(PropertySet.class);
    if (annotation == null)
    {
      annotation = type.getAnnotation(PropertySet.class);
    }
    return annotation;
  }

  private static Document determineDocumentNameAnnotation(final Class<?> type,
      final Method propertyMethod)
  {
    Document annotation = propertyMethod.getAnnotation(Document.class);
    if (annotation == null || StringUtils.isBlank(annotation.name()))
    {
      annotation = type.getAnnotation(Document.class);
    }
    return annotation;
  }

  private static Document determineDocumentTitleAnnotation(final Class<?> type,
      final Method propertyMethod)
  {
    Document annotation = propertyMethod.getAnnotation(Document.class);
    if (annotation == null || StringUtils.isBlank(annotation.title()))
    {
      annotation = type.getAnnotation(Document.class);
    }
    return annotation;
  }

  // --- factory ------------------------------------------------------------

  /**
   * Retruns the property set metadata defaults.
   *
   * @param propertyMethod the method of the property whose set defaults are
   *          requested.
   * @return the defaults for the set referenced by the property identified by
   *         the given method.
   */
  public static PropertyMetaDataDefaults propertySet(final Method propertyMethod)
  {
    final Class<?> type = propertyMethod.getDeclaringClass();
    final String space = createSpace(type);

    final PropertySet annotation = getPropertySetAnnotation(propertyMethod);
    final String title =
        annotation != null ? x(type, annotation) : type.getSimpleName();
    final String name = title;

    final PropertyMetaDataDefaults defaults =
        new PropertyMetaDataDefaults(space, name, title);
    return defaults;
  }

  private static String x(final Class<?> type, final PropertySet annotation)
  {
    String name = annotation.value();
    if (name == null)
    {
      name = type.getSimpleName();
    }
    else if (" ".equals(name))
    {
      name = "";
    }
    return name;
  }

  private static PropertySet getPropertySetAnnotation(
      final Method propertyMethod)
  {
    PropertySet annotation = propertyMethod.getAnnotation(PropertySet.class);
    if (annotation == null)
    {
      final Class<?> type = propertyMethod.getDeclaringClass();
      annotation = type.getAnnotation(PropertySet.class);
    }
    return annotation;
  }

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

  @Override
  public String getTitle()
  {
    return title;
  }

  @Override
  public String getName()
  {
    return name;
  }

  @Override
  public String getSpace()
  {
    return space;
  }

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

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

  /**
   * Returns the string representation of the object.
   *
   * @return the string representation of the object.
   */
  @Override
  public String toString()
  {
    return space + '/' + title + '/' + name;
  }
}