/*
 * 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.runtime.taskexecutor.rpc;

import org.apache.flink.api.common.JobID;
import org.apache.flink.api.common.time.Time;
import org.apache.flink.core.io.InputSplit;
import org.apache.flink.runtime.concurrent.Future;
import org.apache.flink.runtime.executiongraph.ExecutionAttemptID;
import org.apache.flink.runtime.jobgraph.JobVertexID;
import org.apache.flink.runtime.jobgraph.tasks.InputSplitProvider;
import org.apache.flink.runtime.jobgraph.tasks.InputSplitProviderException;
import org.apache.flink.runtime.jobmaster.JobMasterGateway;
import org.apache.flink.runtime.jobmaster.SerializedInputSplit;
import org.apache.flink.util.InstantiationUtil;
import org.apache.flink.util.Preconditions;

import java.util.UUID;

public class RpcInputSplitProvider implements InputSplitProvider {
	private final UUID jobMasterLeaderId;
	private final JobMasterGateway jobMasterGateway;
	private final JobID jobID;
	private final JobVertexID jobVertexID;
	private final ExecutionAttemptID executionAttemptID;
	private final Time timeout;

	public RpcInputSplitProvider(
			UUID jobMasterLeaderId,
			JobMasterGateway jobMasterGateway,
			JobID jobID,
			JobVertexID jobVertexID,
			ExecutionAttemptID executionAttemptID,
			Time timeout) {
		this.jobMasterLeaderId = Preconditions.checkNotNull(jobMasterLeaderId);
		this.jobMasterGateway = Preconditions.checkNotNull(jobMasterGateway);
		this.jobID = Preconditions.checkNotNull(jobID);
		this.jobVertexID = Preconditions.checkNotNull(jobVertexID);
		this.executionAttemptID = Preconditions.checkNotNull(executionAttemptID);
		this.timeout = Preconditions.checkNotNull(timeout);
	}


	@Override
	public InputSplit getNextInputSplit(ClassLoader userCodeClassLoader) throws InputSplitProviderException {
		Preconditions.checkNotNull(userCodeClassLoader);

		Future<SerializedInputSplit> futureInputSplit = jobMasterGateway.requestNextInputSplit(
				jobMasterLeaderId, jobVertexID, executionAttemptID);

		try {
			SerializedInputSplit serializedInputSplit = futureInputSplit.get(timeout.getSize(), timeout.getUnit());

			if (serializedInputSplit.isEmpty()) {
				return null;
			} else {
				return InstantiationUtil.deserializeObject(serializedInputSplit.getInputSplitData(), userCodeClassLoader);
			}
		} catch (Exception e) {
			throw new InputSplitProviderException("Requesting the next input split failed.", e);
		}
	}
}