/*
 * 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.beam.sdk.io.hadoop.inputformat;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapreduce.InputFormat;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.JobContext;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;

/**
 * This is a dummy input format to test reading using HadoopInputFormatIO if InputFormat implements
 * Configurable. This validates if setConf() method is called before getSplits(). Known InputFormats
 * which implement Configurable are DBInputFormat, TableInputFormat etc.
 */
public class ConfigurableEmployeeInputFormat extends InputFormat<Text, Employee> implements
    Configurable {
  public boolean isConfSet = false;

  public ConfigurableEmployeeInputFormat() {}

  @Override
  public Configuration getConf() {
    return null;
  }

  /**
   * Set configuration properties such as number of splits and number of records in each split.
   */
  @Override
  public void setConf(Configuration conf) {
    isConfSet = true;
  }

  @Override
  public RecordReader<Text, Employee> createRecordReader(InputSplit split,
      TaskAttemptContext context) throws IOException, InterruptedException {
    return new ConfigurableEmployeeRecordReader();
  }

  /**
   * Returns InputSPlit list of {@link ConfigurableEmployeeInputSplit}. Throws exception if
   * {@link #setConf()} is not called.
   */
  @Override
  public List<InputSplit> getSplits(JobContext context) throws IOException, InterruptedException {
    if (!isConfSet) {
      throw new IOException("Configuration is not set.");
    }
    List<InputSplit> splits = new ArrayList<InputSplit>();
    splits.add(new ConfigurableEmployeeInputSplit());
    return splits;
  }

  /**
   * InputSplit implementation for ConfigurableEmployeeInputFormat.
   */
  public class ConfigurableEmployeeInputSplit extends InputSplit implements Writable {

    @Override
    public void readFields(DataInput arg0) throws IOException {}

    @Override
    public void write(DataOutput arg0) throws IOException {}

    @Override
    public long getLength() throws IOException, InterruptedException {
      return 0;
    }

    @Override
    public String[] getLocations() throws IOException, InterruptedException {
      return null;
    }
  }

  /**
   * RecordReader for ConfigurableEmployeeInputFormat.
   */
  public class ConfigurableEmployeeRecordReader extends RecordReader<Text, Employee> {

    @Override
    public void initialize(InputSplit paramInputSplit, TaskAttemptContext paramTaskAttemptContext)
        throws IOException, InterruptedException {}

    @Override
    public boolean nextKeyValue() throws IOException, InterruptedException {
      return false;
    }

    @Override
    public Text getCurrentKey() throws IOException, InterruptedException {
      return null;
    }

    @Override
    public Employee getCurrentValue() throws IOException, InterruptedException {
      return null;
    }

    @Override
    public float getProgress() throws IOException, InterruptedException {
      return 0;
    }

    @Override
    public void close() throws IOException {}
  }
}