/*****************************************************************
 *   Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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.cayenne.query;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;

import org.apache.cayenne.ejbql.EJBQLCompiledExpression;
import org.apache.cayenne.map.EntityResolver;
import org.apache.cayenne.map.ObjEntity;

/**
 * A metadata object for the {@link EJBQLQuery}.
 * 
 * @since 3.0
 */
class EJBQLQueryMetadata extends BaseQueryMetadata {

    boolean resolve(EntityResolver resolver, EJBQLQuery query) {
        EJBQLCompiledExpression expression = query.getExpression(resolver);

        resultSetMapping = expression.getResult() != null ? expression
                .getResult()
                .getResolvedComponents(resolver) : null;

        ObjEntity root = expression.getRootDescriptor().getEntity();

        if (super.resolve(root, resolver, null)) {

            if (QueryCacheStrategy.NO_CACHE == getCacheStrategy()) {

            }
            else {

                // create a unique key based on entity, EJBQL, and parameters
                StringBuilder key = new StringBuilder();

                if (query.getEjbqlStatement() != null) {
                    key.append('/').append(query.getEjbqlStatement());
                }

                if (query.getFetchLimit() > 0) {
                    key.append('/').append(query.getFetchLimit());
                }

                Map<String, Object> namedParameters = query.getNamedParameters();
                if (!namedParameters.isEmpty()) {

                    List<String> keys = new ArrayList<String>(namedParameters.keySet());
                    Collections.sort(keys);
                    for (String parameterKey : keys) {
                        key.append('/').append(parameterKey).append('=').append(
                                namedParameters.get(parameterKey));
                    }
                }

                Map<Integer, Object> positionalParameters = query
                        .getPositionalParameters();
                if (!positionalParameters.isEmpty()) {

                    List<Integer> keys = new ArrayList<Integer>(positionalParameters
                            .keySet());
                    Collections.sort(keys);
                    for (Integer parameterKey : keys) {
                        key.append('/').append(parameterKey).append('=').append(
                                positionalParameters.get(parameterKey));
                    }
                }

                this.cacheKey = key.toString();
            }

            return true;
        }

        return false;
    }
}
