use Luhn to calculate ar_SA id numbers.

readme.md

@@ -745,6 +745,7 @@ Fugiat non in itaque sunt nobis totam. Sed nesciunt est deleniti cumque alias. R
 echo $faker->idNumber;      // ID number
 echo $faker->nationalIdNumber // Citizen ID number
 echo $faker->foreignerIdNumber // Foreigner ID number
+echo $faker->companyIdNumber // Company ID number
 ```
 
 ### `Faker\Provider\at_AT\Payment`

src/Faker/Provider/ar_SA/Company.php

@@ -2,6 +2,9 @@
 
 namespace Faker\Provider\ar_SA;
 
+use Faker\Calculator\Luhn;
+use Faker\Provider\ar_SA\Utils;
+
 class Company extends \Faker\Provider\Company
 {
     protected static $formats = array(
@@ -60,4 +63,12 @@ public function bs()
 
         return join($result, ' ');
     }
+
+    /**
+     * example 7001010101
+     **/
+    public static function companyIdNumber()
+    {
+        return Utils::generateLuhnNumber(700, 10);
+    }
 }

src/Faker/Provider/ar_SA/Person.php

@@ -2,6 +2,9 @@
 
 namespace Faker\Provider\ar_SA;
 
+use Faker\Calculator\Luhn;
+use Faker\Provider\ar_SA\Utils;
+
 class Person extends \Faker\Provider\Person
 {
     protected static $maleNameFormats = array(
@@ -90,59 +93,23 @@ public static function prefix()
      */
     public static function idNumber()
     {
-        $firstDigit = static::numberBetween(1, 2);
-
-        do {
-            $number = $firstDigit.static::numerify('#########');
-        } while (!static::checkSum($number));
-
-        return $number;
+        $firstDigit = static::randomElement(array(1, 2));
+        return Utils::generateLuhnNumber($firstDigit, 10);
     }
 
     /**
-     * @example
+     * @example 1010101010
      */
     public static function nationalIdNumber()
     {
-        do {
-            $number = '1'.static::numerify('#########');
-        } while (!static::checkSum($number));
-
-        return $number;
+        return Utils::generateLuhnNumber(1, 10);
     }
 
     /**
-     * @example
+     * @example 2010101010
      */
     public static function foreignerIdNumber()
     {
-        do {
-            $number = '2'.static::numerify('#########');
-        } while (!static::checkSum($number));
-
-        return $number;
-    }
-
-    /**
-     * Check sum the number.
-     * @param $number
-     *
-     * @return bool
-     */
-    protected static function checkSum($number)
-    {
-        $sum  = 0;
-        $nums = str_split($number);
-
-        for ($i = 0; $i < 10; $i++) {
-            if ($i % 2 == 0) {
-                $s = $nums[$i] * 2;
-                $sum += $s % 10 + floor($s / 10);
-            } else {
-                $sum += $nums[$i];
-            }
-        }
-
-        return ($sum % 10 == 0);
+        return Utils::generateLuhnNumber(2, 10);
     }
 }

src/Faker/Provider/ar_SA/Utils.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace Faker\Provider\ar_SA;
+
+class Utils
+{
+    // ripped unashamedly from https://github.com/grahamking/darkcoding-credit-card/blob/master/gencc.php
+    public static function generateLuhnNumber($prefix, $length)
+    {
+
+        $number = $prefix;
+
+        # generate digits
+
+        while (strlen($number) < ($length - 1)) {
+            $number .= mt_rand(0, 9);
+        }
+
+        # Calculate sum
+
+        $sum = 0;
+        $pos = 0;
+
+        $reversedNumber = strrev($number);
+
+        while ($pos < $length - 1) {
+
+            $odd = $reversedNumber[$pos] * 2;
+            if ($odd > 9) {
+                $odd -= 9;
+            }
+
+            $sum += $odd;
+
+            if ($pos != ($length - 2)) {
+
+                $sum += $reversedNumber[$pos +1];
+            }
+            $pos += 2;
+        }
+
+        # Calculate check digit
+
+        $checkdigit = ((floor($sum/10) + 1) * 10 - $sum) % 10;
+        $number .= $checkdigit;
+
+        return $number;
+
+    }
+}

test/Faker/Provider/ar_SA/UtilsTest.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace Faker\Test\Provider\ar_SA;
+
+use Faker\Generator;
+use Faker\Provider\ar_SA\Utils;
+use Faker\Calculator\Luhn;
+
+class UtilsTest extends \PHPUnit_Framework_TestCase
+{
+
+    public function testGeneretedNumber()
+    {
+        $this->assertNotEmpty(Utils::generateLuhnNumber(1, 5));
+    }
+
+    public function testIfGeneretedNumberIsLuhnien()
+    {
+        $this->assertTrue(Luhn::isValid(Utils::generateLuhnNumber(443, 10)));
+        $this->assertTrue(Luhn::isValid(Utils::generateLuhnNumber(5, 15)));
+        $this->assertTrue(Luhn::isValid(Utils::generateLuhnNumber(203, 25)));
+    }
+}