/*
    * Copyright 2001-2008 The Apache Software Foundation.
    * 
    * 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.apache.juddi.query;
  
  import java.util.List;
  import javax.persistence.EntityManager;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.juddi.query.util.DynamicQuery;
  import org.apache.juddi.query.util.FindQualifiers;
  import org.uddi.api_v3.DiscoveryURLs;
  import org.uddi.api_v3.DiscoveryURL;
  
  /**
   * 
   * Returns the list of business keys possessing the DiscoveryUrls in the passed DiscoveryUrl list.
   * Output is restricted by list of business keys passed in.  If null, all businesses are searched.
   * Output is produced by building the appropriate JPA query based on input and find qualifiers.
   * 
   * From specification:
   * "This is a list of discoveryURL structures to be matched against the discoveryURL data associated with registered businessEntity 
   * information.  To search for URL without regard to useType attribute values, omit the useType attribute or pass it as an empty 
   * attribute.  If useType values are included, the match occurs only on registered information that matches both the useType and 
   * URL value.  The returned businessList contains businessInfo structures matching any of the URL's passed (logical OR)."
   * 
   * @author <a href="mailto:jfaath@apache.org">Jeff Faath</a>
   */
  public class FindBusinessByDiscoveryURLQuery extends BusinessEntityQuery {
  
  	@SuppressWarnings("unused")
  	private static Log log = LogFactory.getLog(FindBusinessByDiscoveryURLQuery.class);
  
  	private static final String ENTITY_NAME_CHILD = "DiscoveryUrl";
  
  	private static final String entityAliasChild;;
  	
  	static {
  		entityAliasChild = buildAlias(ENTITY_NAME_CHILD);
  	}
  
  	public static List<Object> select(EntityManager em, FindQualifiers fq, DiscoveryURLs discURLs, 
  			List<Object> keysIn, DynamicQuery.Parameter... restrictions) {
  		// If keysIn is not null and empty, then search is over.
  		if ((keysIn != null) && (keysIn.size() == 0))
  			return keysIn;
  		
  		if (discURLs == null)
  			return keysIn;
  		
  		List<DiscoveryURL> discURLlist = discURLs.getDiscoveryURL();
  		if (discURLlist == null || discURLlist.size() == 0)
  			return keysIn;
  		
  		DynamicQuery dynamicQry = new DynamicQuery(selectSQL);
  		appendConditions(dynamicQry, fq, discURLlist);
  		if (restrictions != null && restrictions.length > 0)
  			dynamicQry.AND().pad().appendGroupedAnd(restrictions);
  
  		return getQueryResult(em, dynamicQry, keysIn, ENTITY_ALIAS + "." + KEY_NAME);
  	}
  	
  	/*
  	 * Appends the conditions to the query based on the discovery url list.  By default, the urls are OR'd and this cannot be changed. 
  	 *	 
  	 */
  	public static void appendConditions(DynamicQuery qry, FindQualifiers fq, List<DiscoveryURL> discURLs) {
  		
  		// Append the necessary tables (one will always be added connecting the entity to its discovery url table).
  		appendJoinTables(qry, fq, discURLs);
  		qry.AND().pad().openParen().pad();
  
  		int count = 0;
  		for(DiscoveryURL discURL : discURLs) {
  			String urlTerm = entityAliasChild + ".url";
  			String urlValue = discURL.getValue();
  			
  			if (discURL.getUseType() == null || discURL.getUseType().length() == 0 ) {
  				qry.appendGroupedAnd(new DynamicQuery.Parameter(urlTerm, urlValue, DynamicQuery.PREDICATE_LIKE));
  			}
  			else {
  				qry.appendGroupedAnd(new DynamicQuery.Parameter(urlTerm, urlValue, DynamicQuery.PREDICATE_LIKE), 
  									 new DynamicQuery.Parameter(entityAliasChild + ".useType", discURL.getUseType(), DynamicQuery.PREDICATE_EQUALS));
  			}
 			
 			if (count + 1 < discURLs.size())
 				qry.OR().pad();
 			
 			count++;
 		}
 		qry.closeParen().pad();
 		
 	}
 	
 	/*
 	 * Appends the necessary join table for the child entity 
 	 */
 	public static void appendJoinTables(DynamicQuery qry, FindQualifiers fq, List<DiscoveryURL> discURLs) {
 		qry.comma().pad().append(ENTITY_NAME_CHILD + " " + entityAliasChild).pad();
 		qry.WHERE().pad().openParen().pad();
 		qry.append(ENTITY_ALIAS + "." + KEY_NAME + " = " + entityAliasChild + "." + ENTITY_FIELD + "." + KEY_NAME + " ");
 		qry.closeParen().pad();
 	}
 	
 }