/*
 * 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.spark.sql.catalyst.util

import org.apache.hadoop.conf.Configuration
import org.apache.hadoop.io.SequenceFile.CompressionType
import org.apache.hadoop.io.compress._

import org.apache.spark.util.Utils

object CompressionCodecs {
  private val shortCompressionCodecNames = Map(
    "none" -> null,
    "uncompressed" -> null,
    "bzip2" -> classOf[BZip2Codec].getName,
    "deflate" -> classOf[DeflateCodec].getName,
    "gzip" -> classOf[GzipCodec].getName,
    "lz4" -> classOf[Lz4Codec].getName,
    "snappy" -> classOf[SnappyCodec].getName)

  /**
   * Return the full version of the given codec class.
   * If it is already a class name, just return it.
   */
  def getCodecClassName(name: String): String = {
    val codecName = shortCompressionCodecNames.getOrElse(name.toLowerCase, name)
    try {
      // Validate the codec name
      if (codecName != null) {
        Utils.classForName(codecName)
      }
      codecName
    } catch {
      case e: ClassNotFoundException =>
        throw new IllegalArgumentException(s"Codec [$codecName] " +
          s"is not available. Known codecs are ${shortCompressionCodecNames.keys.mkString(", ")}.")
    }
  }

  /**
   * Set compression configurations to Hadoop `Configuration`.
   * `codec` should be a full class path
   */
  def setCodecConfiguration(conf: Configuration, codec: String): Unit = {
    if (codec != null) {
      conf.set("mapreduce.output.fileoutputformat.compress", "true")
      conf.set("mapreduce.output.fileoutputformat.compress.type", CompressionType.BLOCK.toString)
      conf.set("mapreduce.output.fileoutputformat.compress.codec", codec)
      conf.set("mapreduce.map.output.compress", "true")
      conf.set("mapreduce.map.output.compress.codec", codec)
    } else {
      // This infers the option `compression` is set to `uncompressed` or `none`.
      conf.set("mapreduce.output.fileoutputformat.compress", "false")
      conf.set("mapreduce.map.output.compress", "false")
    }
  }
}
