Mbright\Validation\Rule\Validate\Isbn

Complexity

Total Complexity

12

Size/Duplication

Total Lines	95
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes

0

4 Methods

Rating	Name	Duplication	Size	Complexity
A	isbn10()	0	27	4
A	normalize()	0	7	2
A	isbn13()	0	15	3
A	__invoke()	0	8	3

<?php

namespace Mbright\Validation\Rule\Validate;

class Isbn implements ValidateRuleInterface
{
    /**
     * Validates that the value represents an ISBN.
     *
     * @param object $subject The subject to be filtered.
     * @param string $field The subject field name.
     *
     * @return bool True if valid, false if not.
     */
    public function __invoke($subject, string $field): bool
    {
        $value = $this->normalize($subject, $field);
        if (!$value) {
            return false;
        }

        return $this->isbn13($value) || $this->isbn10($value);
    }

    /**
     * Removes all non-ISBN characters to test if it is a valid ISBN.
     *
     * @param object $subject The subject to be filtered.
     * @param string $field The subject field name.
     *
     * @return string|false The normalized string, or false on failure.
     */
    public function normalize($subject, $field)
    {
        $value = preg_replace('/(?:(?!([0-9|X$])).)*/', '', $subject->$field);
        if (preg_match('/^[0-9]{10,13}$|^[0-9]{9}X$/', $value)) {
            return $value;
        }
        return false;
    }

    /**
     * Tests if a 13 digit ISBN is correct.
     *
     * @param mixed $value The value to test.
     *
     * @return bool
     */
    protected function isbn13($value)
    {
        if (strlen($value) != 13) {
            return false;
        }

        $even = $value{0} + $value{2} + $value{4} + $value{6} + $value{8} + $value{10} + $value{12};
        $odd = $value{1} + $value{3} + $value{5} + $value{7} + $value{9} + $value{11};
        $sum = $even + ($odd * 3);

        if ($sum % 10) {
            return false;
        }

        return true;
    }

    /**
     * Tests if a 10 digit ISBN is correct.
     *
     * @param mixed $value The value to test.
     *
     * @return bool
     */
    protected function isbn10($value)
    {
        if (strlen($value) != 10) {
            return false;
        }

        $sum = $value{0}
            + $value{1} * 2
            + $value{2} * 3
            + $value{3} * 4
            + $value{4} * 5
            + $value{5} * 6
            + $value{6} * 7
            + $value{7} * 8
            + $value{8} * 9;

        if ($value{9} == 'X') {
            $sum += 100;
        } else {
            $sum += $value{9} * 10;
        }

        if ($sum % 11) {
            return false;
        }

        return true;
    }
}