/*
 * 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.io;

import org.apache.flink.api.common.JobExecutionResult;
import org.apache.flink.api.common.accumulators.LongCounter;
import org.apache.flink.api.common.io.RichOutputFormat;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.io.TextInputFormat;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.core.fs.FileInputSplit;
import org.apache.flink.core.fs.Path;
import org.apache.flink.test.util.JavaProgramTestBase;

import java.io.IOException;
import java.util.concurrent.ConcurrentLinkedQueue;

import static org.junit.Assert.assertEquals;

/**
 * Tests for rich DataSource and DataSink input output formats accessing RuntimeContext by checking
 * accumulator values.
 */
public class RichInputOutputITCase extends JavaProgramTestBase {

    private String inputPath;
    private static ConcurrentLinkedQueue<Integer> readCalls;
    private static ConcurrentLinkedQueue<Integer> writeCalls;

    @Override
    protected void preSubmit() throws Exception {
        inputPath = createTempFile("input", "ab\n" + "cd\n" + "ef\n");
    }

    @Override
    protected void testProgram() throws Exception {
        // test verifying the number of records read and written vs the accumulator counts

        readCalls = new ConcurrentLinkedQueue<Integer>();
        writeCalls = new ConcurrentLinkedQueue<Integer>();
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
        env.createInput(new TestInputFormat(new Path(inputPath))).output(new TestOutputFormat());

        JobExecutionResult result = env.execute();
        Object a = result.getAllAccumulatorResults().get("DATA_SOURCE_ACCUMULATOR");
        Object b = result.getAllAccumulatorResults().get("DATA_SINK_ACCUMULATOR");
        long recordsRead = (Long) a;
        long recordsWritten = (Long) b;
        assertEquals(recordsRead, readCalls.size());
        assertEquals(recordsWritten, writeCalls.size());
    }

    private static final class TestInputFormat extends TextInputFormat {
        private static final long serialVersionUID = 1L;

        private LongCounter counter = new LongCounter();

        public TestInputFormat(Path filePath) {
            super(filePath);
        }

        @Override
        public void initializeSplit(FileInputSplit split, Long offset) throws IOException {
            try {
                getRuntimeContext().addAccumulator("DATA_SOURCE_ACCUMULATOR", counter);
            } catch (UnsupportedOperationException e) {
                // the accumulator is already added
            }
            super.initializeSplit(split, offset);
        }

        @Override
        public String nextRecord(String reuse) throws IOException {
            readCalls.add(1);
            counter.add(1);
            return super.nextRecord(reuse);
        }
    }

    private static final class TestOutputFormat extends RichOutputFormat<String> {

        private LongCounter counter = new LongCounter();

        @Override
        public void configure(Configuration parameters) {}

        @Override
        public void open(int a, int b) {
            try {
                getRuntimeContext().addAccumulator("DATA_SINK_ACCUMULATOR", counter);
            } catch (UnsupportedOperationException e) {
                // the accumulator is already added
            }
        }

        @Override
        public void close() throws IOException {}

        @Override
        public void writeRecord(String record) {
            writeCalls.add(1);
            counter.add(1);
        }
    }
}