/* Copyright (c) 2008 Google Inc.
 *
 * 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 com.google.gdata.model.atompub;

import com.google.gdata.model.Element;
import com.google.gdata.model.ElementCreator;
import com.google.gdata.model.ElementKey;
import com.google.gdata.model.MetadataRegistry;
import com.google.gdata.model.QName;
import com.google.gdata.util.Namespaces;

/**
 * Describes an Atom publication control status.
 *
 * 
 */
public class Control extends Element {

  /**
   * The key for this element.
   */
  public static final ElementKey<Void,
      Control> KEY = ElementKey.of(new QName(Namespaces.atomPubStandardNs,
      "control"), Void.class, Control.class);

  /**
   * Registers the metadata for this element.
   */
  public static void registerMetadata(MetadataRegistry registry) {
    if (registry.isRegistered(KEY)) {
      return;
    }

    // The builder for this element
    ElementCreator builder = registry.build(KEY);

    // Local properties
    builder.addElement(Draft.KEY);
  }

  /**
   * Constructs an instance using the default key.
   */
  public Control() {
    super(KEY);
  }

  /**
   * Subclass constructor, allows subclasses to supply their own element key.
   */
  protected Control(ElementKey<?, ? extends Control> key) {
    super(key);
  }

  /**
   * Constructs a new instance by doing a shallow copy of data from an existing
   * {@link Element} instance. Will use the given {@link ElementKey} as the key
   * for the element. This constructor is used when adapting from one element
   * key to another. You cannot call this constructor directly, instead use
   * {@link Element#createElement(ElementKey, Element)}.
   *
   * @param key The key to use for this element.
   * @param source source element
   */
  protected Control(ElementKey<?, ? extends Control> key, Element source) {
    super(key, source);
  }

   @Override
   public Control lock() {
     return (Control) super.lock();
   }

  /**
   * Returns the draft tag.
   *
   * @return draft tag
   */
  public Draft getDraft() {
    return super.getElement(Draft.KEY);
  }

  /**
   * Sets the draft tag.
   *
   * @param draft draft tag or {@code null} to reset
   * @return this to enable chaining setters
   */
  public Control setDraft(Draft draft) {
    super.setElement(Draft.KEY, draft);
    return this;
  }

  /**
   * Returns whether it has the draft tag.
   *
   * @return whether it has the draft tag
   */
  public boolean hasDraft() {
    return super.hasElement(Draft.KEY);
  }



  /**
   * Checks the value of the app:draft tag.
   *
   * @return true if the entry is a draft (false by default as per RFC5023)
   */
  public boolean isDraft() {
    return hasDraft() && Draft.Value.YES.equals(getElementValue(Draft.KEY));
  }

  /**
   * Sets the value of the app:draft tag.
   *
   * @param value sets the draft status to the specified value, false to clear.
   */
  public void setDraft(boolean value) {
    if (value) {
      setDraft(new Draft(Draft.Value.YES));
    } else {
      removeElement(Draft.KEY);
    }
  }
}