/*

  * Copyright 2007 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.krad.bo;

 import java.io.Serializable;

 import java.util.HashMap;

 import java.util.Map;

 /**

  * Represents a relationship to another class that exists within a given parent class

  *

  * <p>

  * In terms of relational db, this can be thought of as a foreign key relationship. That is one of the

  * properties (fields) of the parent class (parent table) has a relationship to another class (table)

  * </p>

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class DataObjectRelationship implements Serializable {

     private Class<?> relatedClass;

     private Class<?> parentClass;

     private String parentAttributeName;

     private String userVisibleIdentifierKey = null;

     private Map<String, String> parentToChildReferences = new HashMap<String, String>(4);

     public DataObjectRelationship() {

     }

     public DataObjectRelationship(Class<?> parentClass, String parentAttributeName, Class<?> relatedClass) {

         super();

         this.relatedClass = relatedClass;

         this.parentClass = parentClass;

         this.parentAttributeName = parentAttributeName;

     }

     /**

      * Returns the Class that contains the relationship (the parent)

      *

      * @return Class<?> parent class

      */

     public Class<?> getParentClass() {

         return parentClass;

     }

     /**

      * Returns the class the attribute within the parent class has a relationship to

      *

      * @return Class<?> related class

      */

     public Class<?> getRelatedClass() {

         return this.relatedClass;

     }

     /**

      * Returns the name of the attribute within the parent class that holds the related class object

      *

      * <p>

      * Note this attribute should be of type given by #getRelatedClass

      * </p>

      *

      * @return String attribute name within parent class

      */

     public String getParentAttributeName() {

         return parentAttributeName;

     }

     /**

      * Provides a Map of attribute pairs that make up the relationship, where the map key

      * is the attribute name on the parent class and the map value is the attribute name on

      * the related class

      *

      * @return Map<String, String> related attribute pairs

      */

     public Map<String, String> getParentToChildReferences() {

         return parentToChildReferences;

     }

     /**

      * Setter for the Map of attributes that participate in the relationship

      *

      * @param referenceAttributes

      */

     public void setParentToChildReferences(Map<String, String> referenceAttributes) {

         this.parentToChildReferences = referenceAttributes;

     }

     /**

      * Retrieves the attribute within the parent class that is related to the given attribute of

      * the related class by the relationship represented by this object

      *

      * @param childAttributeName - name of attribute within the related class to find parent attribute for

      * @return String attribute name within parent class

      */

     public String getParentAttributeForChildAttribute(String childAttributeName) {

         for (Map.Entry<String, String> entry : parentToChildReferences.entrySet()) {

             if (entry.getValue().equals(childAttributeName)) {

                 return entry.getKey();

             }

         }

         return null;

     }

     /**

      * Retrieves the attribute within the related class that is related to the given attribute of the

      * parent class by the relationship represented by this object

      *

      * @param parentAttributeName - name of attribute within the parent class to find related (child) attribute for

      * @return String attribute name within the related class

      */

     public String getChildAttributeForParentAttribute(String parentAttributeName) {

         return parentToChildReferences.get(parentAttributeName);

     }

     public String getUserVisibleIdentifierKey() {

         return userVisibleIdentifierKey;

     }

     public void setUserVisibleIdentifierKey(String userVisibleIdentifierKey) {

         this.userVisibleIdentifierKey = userVisibleIdentifierKey;

     }

     public String toString() {

         StringBuffer sb = new StringBuffer();

         sb.append("Relationship: ").append(parentClass.getName()).append(" -> ").append(relatedClass.getName());

         for (Map.Entry<String, String> refs : parentToChildReferences.entrySet()) {

             sb.append("\n   ").append(refs.getKey()).append(" -> ").append(refs.getValue());

         }

         return sb.toString();

     }

 }