/*
    * Copyright 2009 the original author or authors.
    * 
    * 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 org.openehealth.ipf.commons.ihe.xds.core.transform.ebxml;
  
  import static org.apache.commons.lang3.Validate.notNull;
  
  import ca.uhn.hl7v2.model.Composite;
  import org.openehealth.ipf.commons.ihe.xds.core.ebxml.EbXMLClassification;
  import org.openehealth.ipf.commons.ihe.xds.core.ebxml.EbXMLFactory;
  import org.openehealth.ipf.commons.ihe.xds.core.ebxml.EbXMLObjectLibrary;
  import org.openehealth.ipf.commons.ihe.xds.core.metadata.*;
  
  import static org.openehealth.ipf.commons.ihe.xds.core.metadata.Vocabulary.*;
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Transforms between an {@link Author} instance and its representation in ebXML.
   * @author Jens Riemschneider
   */
  public class AuthorTransformer {
      private final EbXMLFactory factory;
      
      /**
       * Constructs the transformer
       * @param ebXMLFactory
       *          factory for version independent ebXML objects. 
       */
      public AuthorTransformer(EbXMLFactory ebXMLFactory) {
          notNull(ebXMLFactory, "ebXMLFactory cannot be null");
          factory = ebXMLFactory;
      }
  
      /**
       * Transforms an {@link Author} to a {@link EbXMLClassification}.
       * @param author
       *          the author. Can be <code>null</code>.
       * @param objectLibrary
       *          the object library to use.
       * @return the classification. <code>null</code> if the input was <code>null</code>.
       */
      public EbXMLClassification toEbXML(Author author, EbXMLObjectLibrary objectLibrary) {
          notNull(objectLibrary, "objectLibrary cannot be null");
          
          if (author == null) {
              return null;
          }
          
          EbXMLClassification classification = factory.createClassification(objectLibrary);
          classification.setNodeRepresentation("");
  
          String hl7XCN = Hl7v2Based.render(author.getAuthorPerson());
          if (hl7XCN != null) {
              classification.addSlot(SLOT_NAME_AUTHOR_PERSON, hl7XCN);
          }
  
          transformToHl7Slots(author.getAuthorInstitution(), classification, SLOT_NAME_AUTHOR_INSTITUTION);
          transformToHl7Slots(author.getAuthorRole(),        classification, SLOT_NAME_AUTHOR_ROLE);
          transformToHl7Slots(author.getAuthorSpecialty(),   classification, SLOT_NAME_AUTHOR_SPECIALTY);
          transformToHl7Slots(author.getAuthorTelecom(),     classification, SLOT_NAME_AUTHOR_TELECOM);
  
          return classification;
      }
      
      /**
       * Transforms an a {@link EbXMLClassification} to {@link Author}. 
       * @param classification
       *          the classification. Can be <code>null</code>.
       * @return the author. <code>null</code> if the input was <code>null</code>.
       */
      public Author fromEbXML(EbXMLClassification classification) {
          if (classification == null) {
              return null;        
          }
          
          Author author = new Author();
  
          List<String> persons = classification.getSlotValues(SLOT_NAME_AUTHOR_PERSON);
          if (persons.size() > 0) {
              Person person = Hl7v2Based.parse(persons.get(0), Person.class);
              author.setAuthorPerson(person);
          }
  
          transformFromHl7Slots(classification, SLOT_NAME_AUTHOR_INSTITUTION, author.getAuthorInstitution(), Organization.class);
          transformFromHl7Slots(classification, SLOT_NAME_AUTHOR_ROLE,        author.getAuthorRole(),        Identifiable.class);
         transformFromHl7Slots(classification, SLOT_NAME_AUTHOR_SPECIALTY,   author.getAuthorSpecialty(),   Identifiable.class);
         transformFromHl7Slots(classification, SLOT_NAME_AUTHOR_TELECOM,     author.getAuthorTelecom(),     Telecom.class);
 
         return author;
     }
 
 
     /**
      * Extracts slots with the given name from the given classification,
      * transforms them into HL7-based XDS object model instances
      * of the given type and inserts into the given collection.
      *
      * @param sourceClassification
      *      source classification.
      * @param sourceSlotName
      *      slot name in the source classification.
      * @param targetCollection
      *      target collection of HL7-based object model instances.
      * @param targetClass
      *      target class of the HL7-based object model.
      * @param <T>
      *      target class of the HL7-based object model.
      * @param <C>
      *      composite HAPI type wrapped by {@link T}.
      */
     private static <C extends Composite, T extends Hl7v2Based<C>> void transformFromHl7Slots(
             EbXMLClassification sourceClassification,
             String sourceSlotName,
             List<T> targetCollection,
             Class<T> targetClass)
     {
         for (String source : sourceClassification.getSlotValues(sourceSlotName)) {
             T target = Hl7v2Based.parse(source, targetClass);
             if (target != null) {
                 targetCollection.add(target);
             }
         }
     }
 
 
     /**
      * Renders HL7-based XDS object model instances contained in the given
      * collection and stores them into the given classification
      * as slot values with the given name.
      *
      * @param sourceCollection
      *      source collection of HL7-based object model instances.
      * @param targetClassification
      *      target classification.
      * @param targetSlotName
      *      slot number in the target classification.
      * @param <T>
      *      source class of the HL7-based object model.
      */
     private static <T extends Hl7v2Based<?>> void transformToHl7Slots(
             List<T> sourceCollection,
             EbXMLClassification targetClassification,
             String targetSlotName)
     {
         List<String> targetCollection = new ArrayList<>();
         for (T source : sourceCollection) {
             String target = Hl7v2Based.render(source);
             if (source != null) {
                 targetCollection.add(target);
             }
         }
 
         String[] array = new String[targetCollection.size()];
         targetClassification.addSlot(targetSlotName, targetCollection.toArray(array));
     }
 
 }