CryptoManana\Core\Traits\Randomness\FloatOutputTrait

Complexity

Total Complexity

34

Size/Duplication

Total Lines	176
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes

0

5 Methods

Rating	Name	Duplication	Size	Complexity
A	getProbability()	0	15	6
B	getFloat()	0	39	11
B	getPercent()	0	24	8
A	calculateEpsilon()	0	12	3
A	validateDoubleRange()	0	23	6

<?php

/**
 * Trait implementation of float format generation for generator services.
 */

namespace CryptoManana\Core\Traits\Randomness;

/**
 * Trait FloatOutputTrait - Reusable implementation of `FloatOutputInterface`.
 *
 * @see \CryptoManana\Core\Interfaces\Randomness\FloatOutputInterface The abstract specification.
 *
 * @package CryptoManana\Core\Traits\Randomness
 */
trait FloatOutputTrait
{
    /**
     * Internal method for calculating the machine epsilon value based on the used precision.
     *
     * Note: Passing `null` will use the global system precision value.
     *
     * @param null|int $precision The wanted precision for the machine epsilon.
     *
     * @return float The machine epsilon used for floating number comparison operations.
     */
    protected function calculateEpsilon($precision = null)
    {
        $precision = ($precision === null) ? self::$systemPrecision : $precision;

        // Calculate epsilon based on precision digits
        $epsilon = 0.1;

        for ($i = 1; $i < $precision; $i++) {
            $epsilon *= 0.1;
        }

        return $epsilon;
    }

    /**
     * Internal method for double range validation.
     *
     * @param int|float $from The minimum number in the wanted range.
     * @param int|float $to The maximum number in the wanted range.
     * @param null|int $precision The used precision for comparison.
     *
     * @throws \Exception Validation errors.
     */
    protected function validateDoubleRange($from, $to, $precision = 14)
    {
        $precision = ($precision === null) ? self::$systemPrecision : $precision;

        if ($from < (float)$this->getMinNumber() || $to > (float)$this->getMaxNumber()) {

It seems like getMinNumber() must be provided by classes using this trait. How about adding it as abstract method to this trait?

It seems like getMaxNumber() must be provided by classes using this trait. How about adding it as abstract method to this trait?

            throw new \DomainException(
                "The provided values are out of the supported range."
            );
        }

        if ($from > $to) {
            throw new \LogicException(
                "The chosen generation maximum is less or equal the provided minimum value."
            );
        }

        $epsilon = $this->calculateEpsilon($precision);

        $difference = abs($from - $to);

        if ($difference < $epsilon) {
            throw new \LogicException(
                "The chosen generation maximum is less or equal the provided minimum value."
            );
        }
    }

    /**
     * Generate a probability format float number between 0.0 and 1.0.
     *
     * Note: Passing `null` will use the global system precision value.
     *
     * @param null|int $precision Rounding precision (default => 10).
     *
     * @return float Randomly generated probability value.
     * @throws \Exception Validation errors.
     */
    public function getProbability($precision = 10)
    {
        $precision = ($precision === null) ? self::$systemPrecision : $precision;

        $this->validatePositiveInteger($precision, true);

It seems like validatePositiveInteger() must be provided by classes using this trait. How about adding it as abstract method to this trait?

        $number = $this->getInt(0, $this->getMaxNumber());

It seems like getInt() must be provided by classes using this trait. How about adding it as abstract method to this trait?

        $isNotRangeBoarders = ($number !== 0 && $number !== $this->getMaxNumber());

        $number = ($number === 0) ? 0.00 : ($number === $this->getMaxNumber()) ? 100.00 : (float)$number;

        $number = $isNotRangeBoarders ? round($number / (float)$this->getMaxNumber(), $precision) : $number;

        return $number;
    }

    /**
     * Generate a random float number in a certain range.
     *
     * Note: Passing `null` will use the default parameter value or for precision the global system value.
     *
     * @param null|float|int $from The lowest value to be returned (default => 0.0).
     * @param null|float|int $to The highest value to be returned (default => (float)$this->getMaxNumber()).
     * @param null|int $precision Rounding precision (default => 8).
     *
     * @return float Randomly generated float value.
     * @throws \Exception Validation errors.
     */
    public function getFloat($from = 0.0, $to = null, $precision = 8)
    {
        $precision = ($precision === null) ? self::$systemPrecision : $precision;

        $this->validatePositiveInteger($precision, true);

        $fromInvalidType = !in_array(gettype($from), ['integer', 'double', 'NULL']);
        $toInvalidType = !in_array(gettype($to), ['integer', 'double', 'NULL']);

        if ($fromInvalidType || $toInvalidType) {
            throw new \DomainException(
                "The provided values are of invalid type."
            );
        }

        $from = ($from === null) ? 0.0 : (float)$from;
        $to = ($to === null) ? (float)$this->getMaxNumber() : (float)$to;

        $this->validateDoubleRange($from, $to, $precision);

        $epsilon = $this->calculateEpsilon($precision);

        $toIsTheMaximum = abs($this->getMaxNumber() - $to) < $epsilon;
        $fromIsTheZero = abs(0.0 - $from) < $epsilon;

        $fromIsTheMinimumPlusOne = abs(($this->getMinNumber() + 1.0) - $from) < $epsilon;
        $toIsTheZero = abs(0.0 - $to) < $epsilon;

        // Improves the overall calculation quality for range calls
        if ($toIsTheMaximum && $fromIsTheZero) {
            $from = 0.01;
        } elseif ($toIsTheZero && $fromIsTheMinimumPlusOne) {
            $to = 0.01;
        }

        // Minimum precision for probability fetching
        $scope = ($precision > 14) ? $precision : 14;

        return round($from + $this->getProbability($scope) * abs($to - $from), $precision);
    }

    /**
     * Generate a percentage format float number between 0.0 and 100.0.
     *
     * Note: Passing `null` will use the global system precision value.
     *
     * @param null|int $precision Rounding precision (default => 2).
     * @param bool|int $lowerTheScope Flag for using a smaller calculation range.
     *
     * @return float Randomly generated percentage value.
     * @throws \Exception Validation errors.
     */
    public function getPercent($precision = 2, $lowerTheScope = false)
    {
        $precision = ($precision === null) ? self::$systemPrecision : $precision;

        $this->validatePositiveInteger($precision, true);

        if ($lowerTheScope) {
            $max = 9999; // 0-9999

            $number = $this->getInt(0, $max);

            $isNotRangeBoarders = ($number !== 0 && $number !== $max);

            $number = ($number === 0) ? 0.00 : ($number === $max) ? 100.00 : $number;

            $number = $isNotRangeBoarders ? ($number / $max) * 100.00 : $number;
        } else {
            // Minimum precision for probability fetching
            $scope = ($precision > 14) ? $precision : 14;

            $number = $this->getProbability($scope) * 100.00;
        }

        return round($number, $precision);
    }
}