/*
 * 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.operators.base;

import java.util.List;

import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.ExecutionConfig;
import org.apache.flink.api.common.distributions.DataDistribution;
import org.apache.flink.api.common.functions.Partitioner;
import org.apache.flink.api.common.functions.RuntimeContext;
import org.apache.flink.api.common.functions.util.NoOpFunction;
import org.apache.flink.api.common.operators.Ordering;
import org.apache.flink.api.common.operators.SingleInputOperator;
import org.apache.flink.api.common.operators.SingleInputSemanticProperties;
import org.apache.flink.api.common.operators.UnaryOperatorInformation;
import org.apache.flink.api.common.operators.util.UserCodeObjectWrapper;

/**
 * @param <IN> The input and result type.
 */
@Internal
public class PartitionOperatorBase<IN> extends SingleInputOperator<IN, IN, NoOpFunction> {

	public static enum PartitionMethod {
		REBALANCE,
		HASH,
		RANGE,
		CUSTOM;
	}
	
	// --------------------------------------------------------------------------------------------
	
	private final PartitionMethod partitionMethod;
	
	private Partitioner<?> customPartitioner;
	
	private DataDistribution distribution;

	private Ordering ordering;
	
	
	public PartitionOperatorBase(UnaryOperatorInformation<IN, IN> operatorInfo, PartitionMethod pMethod, int[] keys, String name) {
		super(new UserCodeObjectWrapper<NoOpFunction>(new NoOpFunction()), operatorInfo, keys, name);
		this.partitionMethod = pMethod;
	}

	public PartitionOperatorBase(UnaryOperatorInformation<IN, IN> operatorInfo, PartitionMethod pMethod, String name) {
		super(new UserCodeObjectWrapper<NoOpFunction>(new NoOpFunction()), operatorInfo, name);
		this.partitionMethod = pMethod;
	}
	
	// --------------------------------------------------------------------------------------------
	
	public PartitionMethod getPartitionMethod() {
		return this.partitionMethod;
	}
	
	public Partitioner<?> getCustomPartitioner() {
		return customPartitioner;
	}
	
	public DataDistribution getDistribution() {
		return  this.distribution;
	}

	public void setOrdering(Ordering ordering) {
		this.ordering = ordering;
	}

	public Ordering getOrdering() {
		return ordering;
	}

	public void setDistribution(DataDistribution distribution) {
		this.distribution = distribution;
	}

	public void setCustomPartitioner(Partitioner<?> customPartitioner) {
		if (customPartitioner != null) {
			int[] keys = getKeyColumns(0);
			if (keys == null || keys.length == 0) {
				throw new IllegalArgumentException("Cannot use custom partitioner for a non-grouped GroupReduce (AllGroupReduce)");
			}
			if (keys.length > 1) {
				throw new IllegalArgumentException("Cannot use the key partitioner for composite keys (more than one key field)");
			}
		}
		this.customPartitioner = customPartitioner;
	}
	
	@Override
	public SingleInputSemanticProperties getSemanticProperties() {
		return new SingleInputSemanticProperties.AllFieldsForwardedProperties();
	}

	// --------------------------------------------------------------------------------------------
	
	@Override
	protected List<IN> executeOnCollections(List<IN> inputData, RuntimeContext runtimeContext, ExecutionConfig executionConfig) {
		return inputData;
	}
}