/**
    * Copyright 2005-2012 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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 org.kuali.rice.kew.framework.document.search;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.core.api.CoreConstants;
  import org.kuali.rice.core.api.mo.AbstractDataTransferObject;
  import org.kuali.rice.core.api.uif.RemotableAttributeField;
  import org.w3c.dom.Element;
  
  import javax.xml.bind.annotation.XmlAccessType;
  import javax.xml.bind.annotation.XmlAccessorType;
  import javax.xml.bind.annotation.XmlAnyElement;
  import javax.xml.bind.annotation.XmlElement;
  import javax.xml.bind.annotation.XmlElementWrapper;
  import javax.xml.bind.annotation.XmlRootElement;
  import javax.xml.bind.annotation.XmlType;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  
  /**
   * An immutable data transfer object used to hold a list of {@link RemotableAttributeField} objects and the name of the
   * {@link org.kuali.rice.kew.framework.document.attribute.SearchableAttribute} from which the fields are derived.  This
   * is essentially used as a grouping mechanism in order to identify which fields are sourced from which attributes.
   *
   * <p>Since this class serves primarily as a simple wrapper for use by {@link DocumentSearchCriteriaConfiguration},
   * it does not have a builder, only a single static create method that is used for constructing instances of it.</p>
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  @XmlRootElement(name = AttributeFields.Constants.ROOT_ELEMENT_NAME)
  @XmlAccessorType(XmlAccessType.NONE)
  @XmlType(name = AttributeFields.Constants.TYPE_NAME, propOrder = {
      AttributeFields.Elements.ATTRIBUTE_NAME,
      AttributeFields.Elements.REMOTABLE_ATTRIBUTE_FIELDS,
      CoreConstants.CommonElements.FUTURE_ELEMENTS
  })
  public final class AttributeFields extends AbstractDataTransferObject {
  
  	@XmlElement(name = Elements.ATTRIBUTE_NAME, required = true)
      private final String attributeName;
  
      @XmlElementWrapper(name = Elements.REMOTABLE_ATTRIBUTE_FIELDS, required = true)
      @XmlElement(name = Elements.REMOTABLE_ATTRIBUTE_FIELD, required = false)
      private final List<RemotableAttributeField> remotableAttributeFields;
  
      @SuppressWarnings("unused")
      @XmlAnyElement
      private final Collection<Element> _futureElements = null;
  
      /**
       * Private constructor used only by JAXB.
       */
      @SuppressWarnings("unused")
      private AttributeFields() {
          this.attributeName = null;
          this.remotableAttributeFields = null;
      }
  
      private AttributeFields(String attributeName, List<RemotableAttributeField> remotableAttributeFields) {
          if (StringUtils.isBlank(attributeName)) {
              throw new IllegalArgumentException("attributeName was blank or null");
          }
          if (remotableAttributeFields == null) {
              throw new IllegalArgumentException("attributeFields was blank or null");
          }
          this.attributeName = attributeName;
          this.remotableAttributeFields = Collections.unmodifiableList(new ArrayList<RemotableAttributeField>(remotableAttributeFields));
      }
  
      /**
       * Constract a new instance of {@code AttributeFields} with the given attribute name and list of remotable attribute
       * fields.
       *
       * @param attributeName the name of the attribute, must not be a null or blank value
       * @param attributeFields the remotable attribute fields to associate with the given attribute name
       *
       * @return a new AttributeFields instance containing the given values
       * @throws IllegalArgumentException if the given attributeName is blank or null
       */
      public static AttributeFields create(String attributeName, List<RemotableAttributeField> attributeFields) {
          if (attributeFields == null) {
              attributeFields = Collections.emptyList();
          }
         return new AttributeFields(attributeName, attributeFields);
     }
 
     /**
      * Returns the name of the searchable attribute associated with this attribute fields instance.  Should never return
      * a null or blank value.
      *
      * @return the searchable attribute name of this instance
      */
     public String getAttributeName() {
         return attributeName;
     }
 
     /**
      * Returns a list of remotable attribute fields associated with the searchable attribute name of this instance.
      * This should never return a null reference, though the list returned can be empty.
      *
      * @return a list of remotable attribute fields associated with this instance
      */
     public List<RemotableAttributeField> getRemotableAttributeFields() {
         return remotableAttributeFields;
     }
 
     /**
      * Defines some internal constants used on this class.
      */
     static class Constants {
         final static String ROOT_ELEMENT_NAME = "attributeFields";
         final static String TYPE_NAME = "AttributeFieldsType";
     }
 
     /**
      * A private class which exposes constants which define the XML element names to use when this object is marshalled to XML.
      */
     static class Elements {
         final static String ATTRIBUTE_NAME = "attributeName";
         final static String REMOTABLE_ATTRIBUTE_FIELDS = "remotableAttributeFields";
         final static String REMOTABLE_ATTRIBUTE_FIELD = "remotableAttributeField";
     }
 
 }