/*
 * 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.udf

import java.math.{BigDecimal, RoundingMode}

import org.apache.spark.sql.types.Decimal

object TruncateImpl {

  @inline
  def evaluate(value: Long, scale: Int): Long = {
    value
  }

  @inline
  def evaluate(value: Int, scale: Int): Int = {
    value
  }

  def evaluate(value: Double, scale: Int): Double = {
    evaluate(BigDecimal.valueOf(value), scale).doubleValue()
  }

  def evaluate(value: Float, scale: Int): Float = {
    evaluate(BigDecimal.valueOf(value), scale).floatValue()
  }

  def evaluate(value: Short, scale: Int): Short = {
    evaluate(BigDecimal.valueOf(value), scale).shortValue()
  }

  def evaluate(value: Byte, scale: Int): Byte = {
    evaluate(BigDecimal.valueOf(value), scale).byteValue()
  }

  def evaluate(value: Decimal, scale: Int): Decimal = {
    Decimal.apply(evaluate(value.toJavaBigDecimal, scale))
  }

  private def evaluate(value: BigDecimal, scale: Int): BigDecimal = {
    value.setScale(scale, RoundingMode.DOWN)
  }
}
