/*
 * 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.execution.datasources.orc

import java.util.Locale

import org.apache.orc.OrcConf.COMPRESS

import org.apache.spark.sql.catalyst.{DataSourceOptions, FileSourceOptions}
import org.apache.spark.sql.catalyst.util.CaseInsensitiveMap
import org.apache.spark.sql.errors.QueryExecutionErrors
import org.apache.spark.sql.internal.SQLConf

/**
 * Options for the ORC data source.
 */
class OrcOptions(
    @transient private val parameters: CaseInsensitiveMap[String],
    @transient private val sqlConf: SQLConf)
  extends FileSourceOptions(parameters) {

  import OrcOptions._

  def this(parameters: Map[String, String], sqlConf: SQLConf) =
    this(CaseInsensitiveMap(parameters), sqlConf)

  /**
   * Compression codec to use.
   * Acceptable values are defined in [[shortOrcCompressionCodecNames]].
   */
  val compressionCodec: String = {
    // `compression`, `orc.compress`(i.e., OrcConf.COMPRESS), and `spark.sql.orc.compression.codec`
    // are in order of precedence from highest to lowest.
    val orcCompressionConf = parameters.get(ORC_COMPRESSION)
    val codecName = parameters
      .get(COMPRESSION)
      .orElse(orcCompressionConf)
      .getOrElse(sqlConf.orcCompressionCodec)
      .toLowerCase(Locale.ROOT)
    if (!shortOrcCompressionCodecNames.contains(codecName)) {
      val availableCodecs = shortOrcCompressionCodecNames.keys.map(_.toLowerCase(Locale.ROOT))
      throw QueryExecutionErrors.codecNotAvailableError(codecName, availableCodecs.mkString(", "))
    }
    shortOrcCompressionCodecNames(codecName)
  }

  /**
   * Whether it merges schemas or not. When the given Orc files have different schemas,
   * the schemas can be merged. By default use the value specified in SQLConf.
   */
  val mergeSchema: Boolean = parameters
    .get(MERGE_SCHEMA)
    .map(_.toBoolean)
    .getOrElse(sqlConf.isOrcSchemaMergingEnabled)
}

object OrcOptions extends DataSourceOptions {
  val MERGE_SCHEMA = newOption("mergeSchema")
  val ORC_COMPRESSION = newOption(COMPRESS.getAttribute)
  val COMPRESSION = newOption("compression")

  // The ORC compression short names
  private val shortOrcCompressionCodecNames = OrcCompressionCodec.values().map {
    mapper => mapper.lowerCaseName() -> mapper.getCompressionKind.name()
  }.toMap

  def getORCCompressionCodecName(name: String): String = shortOrcCompressionCodecNames(name)
}
