DummyGenerator\Core\Calculator\LuhnCalculator

Complexity

Total Complexity

8

Size/Duplication

Total Lines	41
Duplicated Lines	0 %

Test Coverage

Coverage

89.47%

Importance

Changes

0

4 Methods

Rating	Name	Duplication	Size	Complexity
A	checksum()	0	14	3
A	computeCheckDigit()	0	9	2
A	isValid()	0	3	1
A	generateLuhnNumber()	0	7	2

<?php

declare(strict_types = 1);

namespace DummyGenerator\Core\Calculator;

use DummyGenerator\Definitions\Calculator\LuhnCalculatorInterface;
use DummyGenerator\Definitions\Extension\Exception\ExtensionArgumentException;

/**
 * Utility class for validating LUHN numbers
 */
class LuhnCalculator implements LuhnCalculatorInterface
{
    protected function checksum(string $number): int
    {
        $length = strlen($number);
        $sum = 0;

        for ($i = $length - 1; $i >= 0; $i -= 2) {
            $sum += (int) $number[$i];
        }

        for ($i = $length - 2; $i >= 0; $i -= 2) {
            $sum += array_sum(str_split((string) ((int) $number[$i] * 2)));

It seems like str_split((string)(int)$number[$i] * 2) can also be of type true; however, parameter $array of array_sum() does only seem to accept array, maybe add an additional type check?

        }

        return $sum % 10;
    }

    public function computeCheckDigit(string $partialNumber): string
    {
        $checkDigit = $this->checksum($partialNumber . '0');

        if ($checkDigit === 0) {
            return '0';
        }

        return (string) (10 - $checkDigit);
    }

    public function isValid(string $number): bool
    {
        return $this->checksum($number) === 0;
    }

    public function generateLuhnNumber(string $partialValue): string
    {
        if (!preg_match('/^\d+$/', $partialValue)) {
            throw new ExtensionArgumentException('Argument should be an integer.');
        }

        return $partialValue . $this->computeCheckDigit($partialValue);
    }
}