/*
 * 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.hive.ql.io.avro;

import static org.apache.avro.file.DataFileConstants.DEFLATE_CODEC;
import static org.apache.avro.mapred.AvroJob.OUTPUT_CODEC;
import static org.apache.avro.file.CodecFactory.DEFAULT_DEFLATE_LEVEL;
import static org.apache.avro.mapred.AvroOutputFormat.DEFLATE_LEVEL_KEY;

import java.io.IOException;
import java.util.Properties;

import org.apache.avro.Schema;
import org.apache.avro.file.CodecFactory;
import org.apache.avro.file.DataFileWriter;
import org.apache.avro.generic.GenericDatumWriter;
import org.apache.avro.generic.GenericRecord;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.ql.exec.FileSinkOperator;
import org.apache.hadoop.hive.ql.io.HiveOutputFormat;
import org.apache.hadoop.hive.serde2.avro.AvroGenericRecordWritable;
import org.apache.hadoop.hive.serde2.avro.AvroSerdeException;
import org.apache.hadoop.hive.serde2.avro.AvroSerdeUtils;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.RecordWriter;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.util.Progressable;

/**
 * Write to an Avro file from a Hive process.
 */
public class AvroContainerOutputFormat
        implements HiveOutputFormat<WritableComparable, AvroGenericRecordWritable> {

  public static final Logger LOG = LoggerFactory.getLogger(AvroContainerOutputFormat.class);

  @Override
  public org.apache.hadoop.hive.ql.exec.FileSinkOperator.RecordWriter getHiveRecordWriter(JobConf jobConf,
         Path path, Class<? extends Writable> valueClass, boolean isCompressed,
         Properties properties, Progressable progressable) throws IOException {
    Schema schema;
    try {
      schema = AvroSerdeUtils.determineSchemaOrThrowException(jobConf, properties);
    } catch (AvroSerdeException e) {
      throw new IOException(e);
    }
    GenericDatumWriter<GenericRecord> gdw = new GenericDatumWriter<GenericRecord>(schema);
    DataFileWriter<GenericRecord> dfw = new DataFileWriter<GenericRecord>(gdw);

    if (isCompressed) {
      int level = jobConf.getInt(DEFLATE_LEVEL_KEY, DEFAULT_DEFLATE_LEVEL);
      String codecName = jobConf.get(OUTPUT_CODEC, DEFLATE_CODEC);
      CodecFactory factory = codecName.equals(DEFLATE_CODEC)
          ? CodecFactory.deflateCodec(level)
          : CodecFactory.fromString(codecName);
      dfw.setCodec(factory);
    }

    dfw.create(schema, path.getFileSystem(jobConf).create(path));
    return new AvroGenericRecordWriter(dfw);
  }

  class WrapperRecordWriter<K extends Writable,V extends Writable> implements RecordWriter<K, V> {
    FileSinkOperator.RecordWriter hiveWriter = null;
    JobConf jobConf;
    Progressable progressable;
    String fileName;

    public WrapperRecordWriter(JobConf jobConf, Progressable progressable, String fileName){
      this.progressable = progressable;
      this.jobConf = jobConf;
      this.fileName = fileName;
    }

    private FileSinkOperator.RecordWriter getHiveWriter() throws IOException {
      if (this.hiveWriter == null){
        Properties properties = new Properties();
        for (AvroSerdeUtils.AvroTableProperties tableProperty : AvroSerdeUtils.AvroTableProperties.values()){
          String propVal;
          if((propVal = jobConf.get(tableProperty.getPropName())) != null){
            properties.put(tableProperty.getPropName(),propVal);
          }
        }

        Boolean isCompressed = jobConf.getBoolean("mapreduce.output.fileoutputformat.compress", false);
        Path path = new Path(this.fileName);
        if(path.getFileSystem(jobConf).isDirectory(path)){
          // This path is only potentially encountered during setup
          // Otherwise, a specific part_xxxx file name is generated and passed in.
          path = new Path(path,"_dummy");
        }

        this.hiveWriter = getHiveRecordWriter(jobConf,path,null,isCompressed, properties, progressable);
      }
      return this.hiveWriter;
    }

    @Override
    public void write(K key, V value) throws IOException {
      getHiveWriter().write(value);
    }

    @Override
    public void close(Reporter reporter) throws IOException {
      // Normally, I'd worry about the blanket false being passed in here, and that
      // it'd need to be integrated into an abort call for an OutputCommitter, but the
      // underlying recordwriter ignores it and throws it away, so it's irrelevant.
      getHiveWriter().close(false);
    }

  }

    //no records will be emitted from Hive
  @Override
  public RecordWriter<WritableComparable, AvroGenericRecordWritable>
  getRecordWriter(FileSystem ignored, JobConf job, String fileName,
      Progressable progress) throws IOException {
    return new WrapperRecordWriter<WritableComparable, AvroGenericRecordWritable>(job,progress,fileName);
  }

  @Override
  public void checkOutputSpecs(FileSystem ignored, JobConf job) throws IOException {
    return; // Not doing any check
  }
}