/*
    * 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.TModelBag;
  
  /**
   * Returns the list of binding keys possessing the tModels in the passed tModelBag.
   * Output is restricted by list of binding keys passed in.  If null, all bindings are searched.
   * Output is produced by building the appropriate JPA query based on input and find qualifiers.
   * 
   * From specification:
   * "This collection of tModelKey elements represent in part or in whole the technical fingerprint of the bindingTemplate 
   * structures for which the search is being performed. At least one of either a tModelBag or a find_tModel argument SHOULD be 
   * supplied, unless a categoryBag based search is being used.  
  
   * If a find_tModel argument is specified (see above), it is treated as an embedded inquiry.  The tModelKeys returned as a 
   * result of this embedded find_tModel argument are used as if they had been 
   * supplied in a tModelBag argument. Changing the order of the keys in the collection or specifying the same tModelKey more than 
   * once does not change the behavior of the find.  
   * 
   * By default, only bindingTemplates that have a technical fingerprint containing 
   * all of the supplied tModelKeys match (logical AND). Specifying appropriate findQualifiers can override this behavior so that 
   * bindingTemplates with a technical fingerprint containing any of the specified tModelKeys are returned (logical OR)." 
   *  
   * @author <a href="mailto:jfaath@apache.org">Jeff Faath</a>
   */
  public class FindBindingByTModelKeyQuery extends BindingTemplateQuery {
  	
  	@SuppressWarnings("unused")
  	private static Log log = LogFactory.getLog(FindBindingByTModelKeyQuery.class);
  
  	public static final String ENTITY_NAME_CHILD = "TmodelInstanceInfo";
  	
  	protected static final String entityAliasChild;
  	
  	static {
  		entityAliasChild = buildAlias(ENTITY_NAME_CHILD);
  	}
  
  	public static List<Object> select(EntityManager em, FindQualifiers fq, TModelBag tModels, String parentKey, 
  			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 (tModels == null)
  			return keysIn;
  		
  		List<String> tmodelKeys = tModels.getTModelKey();
  		if (tmodelKeys == null || tmodelKeys.size() == 0)
  			return keysIn;
  		
  		DynamicQuery dynamicQry = new DynamicQuery(selectSQL);
  		appendConditions(dynamicQry, fq, tmodelKeys);
  		if (parentKey != null && parentKey.length() > 0)
  			dynamicQry.AND().pad().appendGroupedAnd(new DynamicQuery.Parameter(BindingTemplateQuery.ENTITY_ALIAS + "." + BindingTemplateQuery.KEY_NAME_PARENT, parentKey, DynamicQuery.PREDICATE_EQUALS));
  		
  		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 tModelKey list.  With the default or when "orAllKeys" is passed, the keyedReferences are autonomous and are
  	 * all AND'd or OR'd respectively.  
  	 *	 
  	 */
  	public static void appendConditions(DynamicQuery qry, FindQualifiers fq, List<String> tmodelKeys) {
  		
  		// Append the necessary tables (one will always be added connecting the entity to its instanceinfo table).
  		appendJoinTables(qry, fq, tmodelKeys);
  		qry.AND().pad().openParen().pad();
  		
  		int count = 0;
 		int tblCount = -1;
 		for(String tmodelKey : tmodelKeys) {
 			
 			tblCount++;
 			String tmodelKeyTerm = (fq.isOrAllKeys()?entityAliasChild + "0":entityAliasChild + tblCount) + ".tmodelKey";
 			qry.appendGroupedAnd(new DynamicQuery.Parameter(tmodelKeyTerm, tmodelKey, DynamicQuery.PREDICATE_EQUALS));
 			
 			if (count + 1 < tmodelKeys.size()) {
 				if (fq.isOrAllKeys())
 					qry.OR().pad();
 				else
 					qry.AND().pad();
 			}
 			
 			count++;
 		}
 		qry.closeParen().pad();
 		
 	}
 	
 	/*
 	 * Appends the necessary join table for the child entity and additional tables for when keys are AND'd.  This is the default behavior 
 	 * so only need to add additional tables if "orAllKeys" has not been set.
 	 */
 	public static void appendJoinTables(DynamicQuery qry, FindQualifiers fq, List<String> tmodelKeys) {
 		
 		if (tmodelKeys != null && tmodelKeys.size() > 0) {
 
 			StringBuffer thetaJoins = new StringBuffer(200);
 			int tblCount = 0;
 			for(int count = 0; count < tmodelKeys.size(); count++) {
 				if (count != 0) {
 					if (!fq.isOrAllKeys()) {
 						tblCount++;
 						qry.comma().pad().append(ENTITY_NAME_CHILD + " " + entityAliasChild + tblCount).pad();
 						thetaJoins.append(entityAliasChild + (tblCount - 1) + "." + ENTITY_FIELD + "." + KEY_NAME + " = " + entityAliasChild + tblCount + "." + ENTITY_FIELD + "." + KEY_NAME + " ");
 						thetaJoins.append(DynamicQuery.OPERATOR_AND + " ");
 					}
 				}
 				else {
 					qry.comma().pad().append(ENTITY_NAME_CHILD + " " + entityAliasChild + tblCount).pad();
 					thetaJoins.append(ENTITY_ALIAS + "." + KEY_NAME + " = " + entityAliasChild + tblCount + "." + ENTITY_FIELD + "." + KEY_NAME + " ");
 					thetaJoins.append(DynamicQuery.OPERATOR_AND + " ");
 				}
 			}
 			
 			qry.WHERE().pad().openParen().pad();
 
 			String thetaJoinsStr = thetaJoins.toString();
 			if (thetaJoinsStr.endsWith(DynamicQuery.OPERATOR_AND + " "))
 				thetaJoinsStr = thetaJoinsStr.substring(0, thetaJoinsStr.length() - (DynamicQuery.OPERATOR_AND + " ").length());
 			qry.append(thetaJoinsStr);
 
 			qry.closeParen().pad();
 			if (fq!=null && fq.isSignaturePresent()) {
 				qry.AND().pad().openParen().pad().append(BindingTemplateQuery.SIGNATURE_PRESENT).pad().closeParen().pad();
 			}
 		}
 	}
 	
 }