Draw lots for your Christmas surprises!

LotDrawer.php

<?php

/*
 * LotDrawer::draw([
 *     'Frank'  => '[email protected]',
 *     'John'   => '[email protected]',
 *     'Nathan' => '[email protected]',
 *     'Jane'   => '[email protected]',
 * ]);
 */

class LotDrawer
{
    /**
     * Draw lots
     *
     * @param array $names
     * @return array
     */
    public static function draw(array $names): array
    {
        $shuffled = array_keys($names);
        shuffle($shuffled);
        $result = [];

        $index = 0;
        foreach ($names as $name => $email) {
            if ($shuffled[$index] === $name) {
                return self::draw($names);
            }

            $result[] = [
                'name'        => $name,
                'email'       => $email,
                'assigned_to' => $shuffled[$index],
            ];

            $index++;
        }

        return $result;
    }
}