/**
 * 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.hadoop.mapreduce.lib.fieldsel;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.MapReduceTestUtil;
import org.junit.jupiter.api.Test;

import java.text.NumberFormat;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;

public class TestMRFieldSelection {

private static NumberFormat idFormat = NumberFormat.getInstance();
  static {
    idFormat.setMinimumIntegerDigits(4);
    idFormat.setGroupingUsed(false);
  }

  @Test
  public void testFieldSelection() throws Exception {
    launch();
  }
  private static Path testDir = new Path(
    System.getProperty("test.build.data", "/tmp"), "field");
  
  public static void launch() throws Exception {
    Configuration conf = new Configuration();
    FileSystem fs = FileSystem.get(conf);
    int numOfInputLines = 10;

    Path outDir = new Path(testDir, "output_for_field_selection_test");
    Path inDir = new Path(testDir, "input_for_field_selection_test");

    StringBuffer inputData = new StringBuffer();
    StringBuffer expectedOutput = new StringBuffer();
    constructInputOutputData(inputData, expectedOutput, numOfInputLines);
    
    conf.set(FieldSelectionHelper.DATA_FIELD_SEPARATOR, "-");
    conf.set(FieldSelectionHelper.MAP_OUTPUT_KEY_VALUE_SPEC, "6,5,1-3:0-");
    conf.set(
      FieldSelectionHelper.REDUCE_OUTPUT_KEY_VALUE_SPEC, ":4,3,2,1,0,0-");
    Job job = MapReduceTestUtil.createJob(conf, inDir, outDir,
      1, 1, inputData.toString());
    job.setMapperClass(FieldSelectionMapper.class);
    job.setReducerClass(FieldSelectionReducer.class);
    job.setOutputKeyClass(Text.class);
    job.setOutputValueClass(Text.class);
    job.setNumReduceTasks(1);

    job.waitForCompletion(true);
    assertTrue(job.isSuccessful(), "Job Failed!");

    //
    // Finally, we compare the reconstructed answer key with the
    // original one.  Remember, we need to ignore zero-count items
    // in the original key.
    //
    String outdata = MapReduceTestUtil.readOutput(outDir, conf);
    assertEquals(expectedOutput.toString(), outdata, "Outputs doesnt match.");
    fs.delete(outDir, true);
  }

  public static void constructInputOutputData(StringBuffer inputData,
      StringBuffer expectedOutput, int numOfInputLines) {
    for (int i = 0; i < numOfInputLines; i++) {
      inputData.append(idFormat.format(i));
      inputData.append("-").append(idFormat.format(i+1));
      inputData.append("-").append(idFormat.format(i+2));
      inputData.append("-").append(idFormat.format(i+3));
      inputData.append("-").append(idFormat.format(i+4));
      inputData.append("-").append(idFormat.format(i+5));
      inputData.append("-").append(idFormat.format(i+6));
      inputData.append("\n");

      expectedOutput.append(idFormat.format(i+3));
      expectedOutput.append("-" ).append (idFormat.format(i+2));
      expectedOutput.append("-" ).append (idFormat.format(i+1));
      expectedOutput.append("-" ).append (idFormat.format(i+5));
      expectedOutput.append("-" ).append (idFormat.format(i+6));

      expectedOutput.append("-" ).append (idFormat.format(i+6));
      expectedOutput.append("-" ).append (idFormat.format(i+5));
      expectedOutput.append("-" ).append (idFormat.format(i+1));
      expectedOutput.append("-" ).append (idFormat.format(i+2));
      expectedOutput.append("-" ).append (idFormat.format(i+3));
      expectedOutput.append("-" ).append (idFormat.format(i+0));
      expectedOutput.append("-" ).append (idFormat.format(i+1));
      expectedOutput.append("-" ).append (idFormat.format(i+2));
      expectedOutput.append("-" ).append (idFormat.format(i+3));
      expectedOutput.append("-" ).append (idFormat.format(i+4));
      expectedOutput.append("-" ).append (idFormat.format(i+5));
      expectedOutput.append("-" ).append (idFormat.format(i+6));
      expectedOutput.append("\n");
    }
    System.out.println("inputData:");
    System.out.println(inputData.toString());
    System.out.println("ExpectedData:");
    System.out.println(expectedOutput.toString());
  }
}
