Merge branch 'feature/grid'

README.md

@@ -105,6 +105,12 @@ Checks for a valid [European Article Number](https://en.wikipedia.org/wiki/Inter
 
 Optional integer length (8 or 13) to check only for EAN-8 or EAN-13.
 
+### Global Release Identifier (GRid)
+
+The field under validation must be a [Global Release Identifier](https://en.wikipedia.org/wiki/Global_Release_Identifier).
+
+    public Intervention\Validation\Rules\Grid::__construct()
+
 ### Global Trade Item Number (GTIN)
 
 Checks for a valid [Global Trade Item Number](https://en.wikipedia.org/wiki/Global_Trade_Item_Number).

src/Rules/Grid.php

@@ -0,0 +1,79 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Validation\Rules;
+
+use Intervention\Validation\AbstractRegexRule;
+
+class Grid extends AbstractRegexRule
+{
+    /**
+     * {@inheritdoc}
+     *
+     * @see AbstractRegexRule::pattern()
+     */
+    protected function pattern(): string
+    {
+        return "/^(GRID:)?(?P<grid>A1-?[A-Z0-9]{5}-?[A-Z0-9]{10}-?[A-Z0-9])$/";
+    }
+
+    /**
+     * Determine if the validation rule passes.
+     *
+     * @param mixed $value
+     * @return bool
+     */
+    public function isValid(mixed $value): bool
+    {
+        return is_string($value)
+            && parent::isValid(strtoupper($value))
+            && $this->hasValidChecksum($value);
+    }
+
+    /**
+     * Calculate checksum from given grid number
+     *
+     * @param string $value
+     * @return bool
+     */
+    private function hasValidChecksum(string $value): bool
+    {
+        // get GRid from value
+        preg_match($this->pattern(), strtoupper($value), $matches);
+
+        // split GRid into single characters (without dashes)
+        $characters = str_split(
+            str_replace('-', '', $matches['grid'])
+        );
+
+        // extract last (check) character
+        $checkCharacter = array_pop($characters);
+
+        $m = 36;
+        $n = 37;
+        $product = $m;
+        $sum = 0;
+
+        // calculate checksum
+        foreach ($characters as $char) {
+            $sum = ($product + $this->charValue($char)) % $m;
+            $sum = $sum === 0 ? $m : $sum;
+            $product = ($sum * 2) % $n;
+        }
+
+        // compare checksum to check character value
+        return $n - $product === $this->charValue($checkCharacter);
+    }
+
+    /**
+     * Get character value according to GRid standard v2.1
+     *
+     * @param string $char
+     * @return int
+     */
+    private function charValue(string $char): int
+    {
+        return is_numeric($char) ? (int) $char : (int) str_replace(range('A', 'Z'), range(10, 35), strtoupper($char));
+    }
+}

tests/Rules/GridTest.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Validation\Tests\Rules;
+
+use PHPUnit\Framework\Attributes\DataProvider;
+use Intervention\Validation\Rules\Grid;
+use PHPUnit\Framework\TestCase;
+
+final class GridTest extends TestCase
+{
+    #[DataProvider('dataProvider')]
+    public function testValidation($result, $value): void
+    {
+        $valid = (new Grid())->isValid($value);
+        $this->assertEquals($result, $valid);
+    }
+
+    public static function dataProvider(): array
+    {
+        return [
+            [true, 'A12425GABC1234002M'],
+            [true, 'a12425gabc1234002m'], // lowercase valid
+            [true, 'GRid:A12425GABC1234002M'],
+            [true, 'GRID:A12425GABC1234002M'],
+            [true, 'A1-2425G-ABC1234002-M'],
+            [true, 'A1-2425GABC1234002M'], // only one dash valid
+            [true, 'GRid:A1-2425G-ABC1234002-M'],
+            [true, 'GRID:A1-2425G-ABC1234002-M'],
+            [true, 'A11244BC12345678DP'],
+            [true, 'A1-1244B-C12345678D-P'],
+            [true, 'GRid:A11244BC12345678DP'],
+            [true, 'GRID:A11244BC12345678DP'],
+            [true, 'GRid:A1-1244B-C12345678D-P'],
+            [true, 'GRID:A1-1244B-C12345678D-P'],
+            [false, 'FOO:A1-1244B-C12345678D-P'], // false prefix
+            [false, 'B1-1244B-C12345678D-P'], // false Identifier Scheme element
+            [false, 'A1-1244B-C12345678D-A'], // false Check Character
+            [false, 'ZA9382189201'], // no grid
+            [false, ''], // empty
+        ];
+    }
+}