/*!
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 *
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

//https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/pow
@function pow($number, $power) {
  @if ($power != $power or ($power != 0 and $power == $power / 2)) {
    @return $power;
  }
  @if ($power == 1) {
    @return $number;
  }
  @if ($power == 0) {
    @return 1;
  }
  @if ($power < 0) {
    @return 1 / pow($number, -$power);
  }
  @if (0 < $power and $power < 2) {
    $hasLeadingOne: false;
    @if (floor($power) == 1) {
      $power: $power - 1;
      $hasLeadingOne: true;
    } @else {
      $hasLeadingOne: false;
    }
    $doublePower: pow($number, $power * 2);
    $fullPower: nthRoot($doublePower, 2);
    @if ($hasLeadingOne) {
      $fullPower: $fullPower * $number;
    }
    @return $fullPower;
  } @else if (getDecimal($power) != 0) {
    $wholePower: floor($power);
    $decimalPower: getDecimal($power);
    @return pow($number, $wholePower) * pow($number, $decimalPower);
  } @else {
    $hasTrailingOne: $power % 2 == 1;
    @if ($hasTrailingOne) {
      $power: $power - 1;
    }
    $halfPower: pow($number, floor($power / 2));
    $fullPower: $halfPower * $halfPower;
    @if ($hasTrailingOne) {
      $fullPower: $fullPower * $number;
    }
    @return $fullPower;
  }
}

@function getDecimal($number) {
  @if ($number < 0) {
    $number: -$number;
  }
  @return $number % 1;
}

// From: http://rosettacode.org/wiki/Nth_root#JavaScript
@function nthRoot($num, $n: 2, $prec: 12) {
  $x: 1;

  @for $i from 0 through $prec {
    $x: 1 / $n * (($n - 1) * $x + ($num / pow($x, $n - 1)));
  }

  @return $x;
}