/*
 * 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.test.classloading.jar;

import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.common.io.InputFormat;
import org.apache.flink.api.common.io.statistics.BaseStatistics;
import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.api.java.typeutils.ResultTypeQueryable;
import org.apache.flink.configuration.AkkaOptions;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.core.io.InputSplit;
import org.apache.flink.core.io.InputSplitAssigner;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.sink.SinkFunction;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * Test class used by the {@link org.apache.flink.test.classloading.ClassLoaderITCase}.
 */
@SuppressWarnings("serial")
public class StreamingCustomInputSplitProgram {

	public static void main(String[] args) throws Exception {
				Configuration config = new Configuration();

		config.setString(AkkaOptions.ASK_TIMEOUT, "5 s");

		StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

		env.getConfig().disableSysoutLogging();

		DataStream<Integer> data = env.createInput(new CustomInputFormat());

		data.map(new MapFunction<Integer, Tuple2<Integer, Double>>() {
			@Override
			public Tuple2<Integer, Double> map(Integer value) throws Exception {
				return new Tuple2<Integer, Double>(value, value * 0.5);
			}
		}).addSink(new NoOpSink());

		env.execute();
	}
	// --------------------------------------------------------------------------------------------

	private static final class CustomInputFormat implements InputFormat<Integer, CustomInputSplit>, ResultTypeQueryable<Integer> {

		private static final long serialVersionUID = 1L;

		private Integer value;

		CustomInputSplit split = new CustomInputSplit(0);

		@Override
		public void configure(Configuration parameters) {}

		@Override
		public BaseStatistics getStatistics(BaseStatistics cachedStatistics) {
			return null;
		}

		@Override
		public CustomInputSplit[] createInputSplits(int minNumSplits) {
			CustomInputSplit[] splits = new CustomInputSplit[minNumSplits];
			for (int i = 0; i < minNumSplits; i++) {
				splits[i] = new CustomInputSplit(i);
			}
			return splits;
		}

		@Override
		public InputSplitAssigner getInputSplitAssigner(CustomInputSplit[] inputSplits) {
			return new CustomSplitAssigner(inputSplits);
		}

		@Override
		public void open(CustomInputSplit split) {
			this.value = split.getSplitNumber();
		}

		@Override
		public boolean reachedEnd() {
			return this.value == null;
		}

		@Override
		public Integer nextRecord(Integer reuse) {
			Integer val = this.value;
			this.value = null;
			return val;
		}

		@Override
		public void close() {}

		@Override
		public TypeInformation<Integer> getProducedType() {
			return BasicTypeInfo.INT_TYPE_INFO;
		}
	}

	private static final class CustomInputSplit implements InputSplit {

		private static final long serialVersionUID = 1L;

		private final int splitNumber;

		public CustomInputSplit(int splitNumber) {
			this.splitNumber = splitNumber;
		}

		@Override
		public int getSplitNumber() {
			return this.splitNumber;
		}
	}

	private static final class CustomSplitAssigner implements InputSplitAssigner, Serializable {

		private final List<CustomInputSplit> remainingSplits;

		public CustomSplitAssigner(CustomInputSplit[] splits) {
			this.remainingSplits = new ArrayList<CustomInputSplit>(Arrays.asList(splits));
		}

		@Override
		public InputSplit getNextInputSplit(String host, int taskId) {
			synchronized (this) {
				int size = remainingSplits.size();
				if (size > 0) {
					return remainingSplits.remove(size - 1);
				} else {
					return null;
				}
			}
		}

		@Override
		public void returnInputSplit(List<InputSplit> splits, int taskId) {
			synchronized (this) {
				for (InputSplit split : splits) {
					remainingSplits.add((CustomInputSplit) split);
				}
			}
		}
	}

	private static class NoOpSink implements SinkFunction<Tuple2<Integer, Double>> {
		@Override
		public void invoke(Tuple2<Integer, Double> value) throws Exception {
		}
	}
}
