/*
    * 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.requests;
  
  import org.openehealth.ipf.commons.ihe.xds.core.ebxml.EbXMLAdhocQueryRequest;
  import org.openehealth.ipf.commons.ihe.xds.core.ebxml.EbXMLFactory;
  import org.openehealth.ipf.commons.ihe.xds.core.ebxml.ebxml30.EbXMLFactory30;
  import org.openehealth.ipf.commons.ihe.xds.core.requests.QueryRegistry;
  import org.openehealth.ipf.commons.ihe.xds.core.requests.query.Query;
  import org.openehealth.ipf.commons.ihe.xds.core.requests.query.QueryReturnType;
  import org.openehealth.ipf.commons.ihe.xds.core.requests.query.QueryType;
  
  /**
   * Transforms between a {@link QueryRegistry} and an {@link EbXMLAdhocQueryRequest}. 
   * @author Jens Riemschneider
   */
  public class QueryRegistryTransformer {
      private final EbXMLFactory factory30 = new EbXMLFactory30();
      
      /**
       * Transforms the request into its ebXML representation.
       * @param request
       *          the request. Can be <code>null</code>.
       * @return the ebXML representation. <code>null</code> if the input was <code>null</code>.
       */
      public EbXMLAdhocQueryRequest toEbXML(QueryRegistry request) {
          if (request == null) {
              return null;
          }
          
          Query query = request.getQuery();
          EbXMLAdhocQueryRequest ebXML = createAdhocQueryRequest();
          query.accept(new ToEbXMLVisitor(ebXML));        
  
          ebXML.setReturnType(request.getReturnType().getCode());
  
          return ebXML;        
      }
  
      /**
       * Transforms the ebXML representation into a request.
       * @param ebXML
       *          the ebXML representation. Can be <code>null</code>.
       * @return the request. <code>null</code> if the input was <code>null</code>.
       */
      public QueryRegistry fromEbXML(EbXMLAdhocQueryRequest ebXML) {
          if (ebXML == null) {
              return null;
          }
          
          String id = ebXML.getId();
          QueryType queryType = QueryType.valueOfId(id);
          if (queryType == null) {
              return null;
          }
          
          Query query = createQuery(queryType);        
          query.accept(new FromEbXMLVisitor(ebXML));
          
          QueryRegistry queryRegistry = new QueryRegistry(query);
          queryRegistry.setReturnType(QueryReturnType.valueOfCode(ebXML.getReturnType()));
  
          return queryRegistry;
      }
  
      private Query createQuery(QueryType queryType) {
          try {
              return queryType.getType().newInstance();
          } catch (InstantiationException | IllegalAccessException e) {
              throw new IllegalStateException("Invalid query class for type: " + queryType, e);
          }
      }
  
      private EbXMLAdhocQueryRequest createAdhocQueryRequest() {
          return factory30.createAdhocQueryRequest();
      }
  }