FindServiceByTModelKeyQuery

/*
 * 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 service keys with bindings that possess the tModels in the passed tModelBag.
 * Output is restricted by list of service keys passed in.  If null, all services are searched.
 * Output is produced by building the appropriate JPA query based on input and find qualifiers.
 *
 * From specification:
 * "Every Web service instance is represented in UDDI by a bindingTemplate contained within some businessService. A
 * bindingTemplate contains a collection of  tModel references called its "technical fingerprint" that specifies its type.
 * The tModelBag argument is a collection of tModelKey values specifying that the search results are to be limited to
 * businessServices containing bindingTemplates with technical fingerprints that match.
 *
 * If a find_tModel argument is specified (see below), 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 contain all of the tModelKeys in the technical fingerprint match (logical AND). Specifying
 * appropriate findQualifiers can override this behavior so that bindingTemplates containing any of the specified tModelKeys
 * match (logical OR)."
 *
 * @author <a href="mailto:jfaath@apache.org">Jeff Faath</a>
 * @author <a href="mailto:tcunning@apache.org">Tom Cunningham</a>
 */
public class FindServiceByTModelKeyQuery extends BusinessServiceQuery {

	@SuppressWarnings("unused")
	private static Log log = LogFactory.getLog(FindServiceByTModelKeyQuery.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.isEmpty()))
			return keysIn;

		if (tModels == null)
			return keysIn;

		List<String> tmodelKeys = tModels.getTModelKey();
		if (tmodelKeys == null || tmodelKeys.isEmpty())
			return keysIn;

		DynamicQuery dynamicQry = new DynamicQuery(selectSQL);
		appendConditions(dynamicQry, fq, tmodelKeys);
		if (parentKey != null && parentKey.length() > 0)
			dynamicQry.AND().pad().appendGroupedAnd(new DynamicQuery.Parameter(BusinessServiceQuery.ENTITY_ALIAS + "." + BusinessServiceQuery.KEY_NAME_PARENT, parentKey, DynamicQuery.PREDICATE_EQUALS));
			//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) {
			qry.comma().pad().append(BindingTemplateQuery.ENTITY_NAME + " " + BindingTemplateQuery.ENTITY_ALIAS).pad();

			StringBuilder thetaJoins = new StringBuilder(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).append(tblCount - 1).append("." + BindingTemplateQuery.ENTITY_FIELD + "." + BindingTemplateQuery.KEY_NAME + " = ").append(entityAliasChild).append(tblCount).append("." + BindingTemplateQuery.ENTITY_FIELD + "." + BindingTemplateQuery.KEY_NAME + " ");
						thetaJoins.append(DynamicQuery.OPERATOR_AND + " ");
					}
				}
				else {
					qry.comma().pad().append(ENTITY_NAME_CHILD + " " + entityAliasChild + tblCount).pad();
					thetaJoins.append(BindingTemplateQuery.ENTITY_ALIAS + "." + BindingTemplateQuery.KEY_NAME + " = ").append(entityAliasChild).append(tblCount).append("." + BindingTemplateQuery.ENTITY_FIELD + "." + BindingTemplateQuery.KEY_NAME + " ");
					thetaJoins.append(DynamicQuery.OPERATOR_AND + " ");
				}
			}

			qry.WHERE().pad().openParen().pad();

			qry.append(ENTITY_ALIAS + "." + KEY_NAME + " = " + BindingTemplateQuery.ENTITY_ALIAS + "." + ENTITY_FIELD + "." + KEY_NAME).pad();
			qry.AND().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(BusinessServiceQuery.SIGNATURE_PRESENT).pad().closeParen().pad();
			}
		}
	}

}