/*
 * 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.streaming.connectors.kinesis.testutils;

import org.apache.commons.lang3.RandomStringUtils;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.source.SourceFunction;
import org.apache.flink.streaming.connectors.kinesis.FlinkKinesisProducer;
import org.apache.flink.streaming.connectors.kinesis.config.AWSConfigConstants;
import org.apache.flink.streaming.util.serialization.SimpleStringSchema;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Properties;
import java.util.concurrent.atomic.AtomicReference;

/**
 * A thread that runs a topology with a manual data generator as source, and the FlinkKinesisProducer as sink.
 */
public class KinesisEventsGeneratorProducerThread {

	private static final Logger LOG = LoggerFactory.getLogger(KinesisEventsGeneratorProducerThread.class);

	public static Thread create(final int totalEventCount,
								final int parallelism,
								final String awsAccessKey,
								final String awsSecretKey,
								final String awsRegion,
								final String kinesisStreamName,
								final AtomicReference<Throwable> errorHandler,
								final int flinkPort,
								final Configuration flinkConfig) {
		Runnable kinesisEventsGeneratorProducer = new Runnable() {
			@Override
			public void run() {
				try {
					StreamExecutionEnvironment see = StreamExecutionEnvironment.createRemoteEnvironment("localhost", flinkPort, flinkConfig);
					see.setParallelism(parallelism);

					// start data generator
					DataStream<String> simpleStringStream = see.addSource(new KinesisEventsGeneratorProducerThread.EventsGenerator(totalEventCount)).setParallelism(1);

					Properties producerProps = new Properties();
					producerProps.setProperty(AWSConfigConstants.AWS_ACCESS_KEY_ID, awsAccessKey);
					producerProps.setProperty(AWSConfigConstants.AWS_SECRET_ACCESS_KEY, awsSecretKey);
					producerProps.setProperty(AWSConfigConstants.AWS_REGION, awsRegion);

					FlinkKinesisProducer<String> kinesis = new FlinkKinesisProducer<>(new SimpleStringSchema(),
						producerProps);

					kinesis.setFailOnError(true);
					kinesis.setDefaultStream(kinesisStreamName);
					kinesis.setDefaultPartition("0");
					simpleStringStream.addSink(kinesis);

					LOG.info("Starting producing topology");
					see.execute("Producing topology");
					LOG.info("Producing topo finished");
				} catch (Exception e) {
					LOG.warn("Error while running producing topology", e);
					errorHandler.set(e);
				}
			}
		};

		return new Thread(kinesisEventsGeneratorProducer);
	}

	private static class EventsGenerator implements SourceFunction<String> {

		private static final Logger LOG = LoggerFactory.getLogger(EventsGenerator.class);

		private boolean running = true;
		private final long limit;

		public EventsGenerator(long limit) {
			this.limit = limit;
		}

		@Override
		public void run(SourceContext<String> ctx) throws Exception {
			long seq = 0;
			while(running) {
				Thread.sleep(10);
				String evt = (seq++) + "-" + RandomStringUtils.randomAlphabetic(12);
				ctx.collect(evt);
				LOG.info("Emitting event {}", evt);
				if(seq >= limit) {
					break;
				}
			}
			ctx.close();
			LOG.info("Stopping events generator");
		}

		@Override
		public void cancel() {
			running = false;
		}
	}
}