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 *   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.Collection;
import java.util.List;

import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.ObjectContext;
import org.apache.cayenne.ResultBatchIterator;
import org.apache.cayenne.ResultIterator;
import org.apache.cayenne.ResultIteratorCallback;
import org.apache.cayenne.exp.Expression;
import org.apache.cayenne.map.DbEntity;
import org.apache.cayenne.map.EntityResolver;
import org.apache.cayenne.map.ObjEntity;

/**
 * Base class for {@link ObjectSelect} and {@link ColumnSelect}
 *
 * @since 4.0
 */
public abstract class FluentSelect<T> extends IndirectQuery implements Select<T> {

    protected Class<?> entityType;
    protected String entityName;
    protected String dbEntityName;
    protected Expression where;
    protected Collection<Ordering> orderings;
    protected PrefetchTreeNode prefetches;
    protected int limit;
    protected int offset;
    protected int pageSize;
    protected int statementFetchSize;
    protected QueryCacheStrategy cacheStrategy;
    protected String cacheGroup;

    protected FluentSelect() {
    }

    /**
     * Translates self to a SelectQuery.
     */
    @SuppressWarnings({"deprecation", "unchecked"})
    @Override
    protected Query createReplacementQuery(EntityResolver resolver) {

        @SuppressWarnings("rawtypes")
        SelectQuery replacement = new SelectQuery();

        if (entityType != null) {
            replacement.setRoot(entityType);
        } else if (entityName != null) {

            ObjEntity entity = resolver.getObjEntity(entityName);
            if (entity == null) {
                throw new CayenneRuntimeException("Unrecognized ObjEntity name: %s", entityName);
            }

            replacement.setRoot(entity);
        } else if (dbEntityName != null) {

            DbEntity entity = resolver.getDbEntity(dbEntityName);
            if (entity == null) {
                throw new CayenneRuntimeException("Unrecognized DbEntity name: %s", dbEntityName);
            }

            replacement.setRoot(entity);
        } else {
            throw new CayenneRuntimeException("Undefined root entity of the query");
        }

        replacement.setName(name);
        replacement.setQualifier(where);
        replacement.addOrderings(orderings);
        replacement.setPrefetchTree(prefetches);
        replacement.setCacheStrategy(cacheStrategy);
        replacement.setCacheGroup(cacheGroup);
        replacement.setFetchLimit(limit);
        replacement.setFetchOffset(offset);
        replacement.setPageSize(pageSize);
        replacement.setStatementFetchSize(statementFetchSize);

        return replacement;
    }

    public String getCacheGroup() {
        return cacheGroup;
    }

    public QueryCacheStrategy getCacheStrategy() {
        return cacheStrategy;
    }

    public int getStatementFetchSize() {
        return statementFetchSize;
    }

    public int getPageSize() {
        return pageSize;
    }

    public int getLimit() {
        return limit;
    }

    public int getOffset() {
        return offset;
    }

    public Class<?> getEntityType() {
        return entityType;
    }

    public String getEntityName() {
        return entityName;
    }

    public String getDbEntityName() {
        return dbEntityName;
    }

    /**
     * Returns a WHERE clause Expression of this query.
     */
    public Expression getWhere() {
        return where;
    }

    public Collection<Ordering> getOrderings() {
        return orderings;
    }

    public PrefetchTreeNode getPrefetches() {
        return prefetches;
    }

    @Override
    public List<T> select(ObjectContext context) {
        return context.select(this);
    }

    @Override
    public T selectOne(ObjectContext context) {
        return context.selectOne(this);
    }

    @Override
    public void iterate(ObjectContext context, ResultIteratorCallback<T> callback) {
        context.iterate(this, callback);
    }

    @Override
    public ResultIterator<T> iterator(ObjectContext context) {
        return context.iterator(this);
    }

    @Override
    public ResultBatchIterator<T> batchIterator(ObjectContext context, int size) {
        return context.batchIterator(this, size);
    }
}