glastree_on_gitea

vendor/fakerphp/faker/src/Faker/Calculator/Ean.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace Faker\Calculator;
+
+/**
+ * Utility class for validating EAN-8 and EAN-13 numbers
+ */
+class Ean
+{
+    /**
+     * @var string EAN validation pattern
+     */
+    public const PATTERN = '/^(?:\d{8}|\d{13})$/';
+
+    /**
+     * Computes the checksum of an EAN number.
+     *
+     * @see https://en.wikipedia.org/wiki/International_Article_Number
+     *
+     * @return int
+     */
+    public static function checksum(string $digits)
+    {
+        $sequence = (strlen($digits) + 1) === 8 ? [3, 1] : [1, 3];
+        $sums = 0;
+
+        foreach (str_split($digits) as $n => $digit) {
+            $sums += ((int) $digit) * $sequence[$n % 2];
+        }
+
+        return (10 - $sums % 10) % 10;
+    }
+
+    /**
+     * Checks whether the provided number is an EAN compliant number and that
+     * the checksum is correct.
+     *
+     * @param string $ean An EAN number
+     *
+     * @return bool
+     */
+    public static function isValid(string $ean)
+    {
+        if (!preg_match(self::PATTERN, $ean)) {
+            return false;
+        }
+
+        return self::checksum(substr($ean, 0, -1)) === (int) substr($ean, -1);
+    }
+}