/*
 * 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.storm.sql;

import java.util.List;

import org.apache.calcite.DataContext;
import org.apache.storm.generated.StormTopology;
import org.apache.storm.sql.javac.CompilingClassLoader;
import org.apache.storm.streams.Stream;
import org.apache.storm.tuple.Values;

public abstract class AbstractStreamsProcessor {
    protected Stream<Values> outputStream;
    protected DataContext dataContext;
    protected List<CompilingClassLoader> classLoaders;

    /**
     * Return final output stream of SQL topology structure.
     *
     * @return the output stream of the SQL
     */
    public Stream<Values> outputStream() {
        return outputStream;
    }

    /**
     * Construct the Storm topology based on the SQL.
     */
    public abstract StormTopology build();

    /**
     * Return DataContext instance which is used with execution of query.
     *
     * @return DataContext instance which is used with execution of query
     */
    public DataContext getDataContext() {
        return dataContext;
    }

    /**
     * Return the list of Classloaders which need to be compiled and included to the jar.
     * They're all chaining so the last classloader can access all classes.
     *
     * @return Classloaders to compile.
     */
    public List<CompilingClassLoader> getClassLoaders() {
        return classLoaders;
    }
}