Генерация пароля

$groups = [];
$groups[] = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','r','s','t','u','v','x','y','z'];
$groups[] = ['A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','R','S','T','U','V','X','Y','Z'];
$groups[] = ['1','2','3','4','5','6','7','8','9','0'];
$groups[] = ['.',',','(',')','[',']','!','?','&','^','%','@','*','$','<','>','/','|','+','-','{','}','`','~'];

$password = [];

foreach ($groups as $group) {
    shuffle($group);
    $symbols = array_slice($group, 0, rand(3, 7));
    $password = array_merge($password, $symbols);
}
shuffle($password);
$password = implode('', $password);
echo $password;