/*
 * 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.flink.api.common.functions.util;

import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.functions.Function;
import org.apache.flink.api.common.functions.RichFunction;
import org.apache.flink.api.common.functions.RuntimeContext;
import org.apache.flink.configuration.Configuration;

/**
 * Utility class that contains helper methods to work with Flink {@link Function} class.
 */
@Internal
public final class FunctionUtils {

	public static void openFunction(Function function, Configuration parameters) throws Exception{
		if (function instanceof RichFunction) {
			RichFunction richFunction = (RichFunction) function;
			richFunction.open(parameters);
		}
	}

	public static void closeFunction(Function function) throws Exception{
		if (function instanceof RichFunction) {
			RichFunction richFunction = (RichFunction) function;
			richFunction.close();
		}
	}

	public static void setFunctionRuntimeContext(Function function, RuntimeContext context){
		if (function instanceof RichFunction) {
			RichFunction richFunction = (RichFunction) function;
			richFunction.setRuntimeContext(context);
		}
	}

	public static RuntimeContext getFunctionRuntimeContext(Function function, RuntimeContext defaultContext){
		if (function instanceof RichFunction) {
			RichFunction richFunction = (RichFunction) function;
			return richFunction.getRuntimeContext();
		}
		else {
			return defaultContext;
		}
	}

	/**
	 * Private constructor to prevent instantiation.
	 */
	private FunctionUtils() {
		throw new RuntimeException();
	}
}