<?php

class RegisterValidator
{
    private $login = '';
    private $email = '';
    private $password = '';
    private $birthday = '';
    private $sex = 0;

    public function setLogin($login)
    {
        $login = preg_replace('!\s+!', ' ', $login); // remove inner spaces
        $login = trim($login); // remove outer spaces
        if ($this->loginIsAllowed($login) && !$this->loginIsMixed($login)) {
            $this->login = $login;
        }
        return $this;
    }

    private function loginIsAllowed($login)
    {
        $disallowed = [
            'Мироздатель',
            'Мусорщик',
            'Комментатор',
        ];
        $d = implode('|', $disallowed);
        $pattern = "/\b($d)\b/iu";
        return !preg_match($pattern, $login);
    }

    private function loginIsMixed($login)
    {
        $en = preg_match("/^(([0-9A-z -])+)$/iu", $login);
        $ru = preg_match("/^([а-яёіїє\s\d]*)$/iu", $login);
        return ($ru && $en) || (!$ru && !$en);
    }

    public function setEmail($email)
    {
        if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
            $this->email = $email;
        }
        return $this;
    }

    public function setPassword($password, $passwordVerify)
    {
        if ($this->password === $passwordVerify) {
            $this->password = md5($password);
        }
        return $this;
    }

    public function setBirthday($birthday)
    {
        $bdate = DateTime::createFromFormat('Y-m-d', $birthday);
        if ($bdate) {
            $this->birthday = $bdate->format('d.m.Y');
        }
        return $this;
    }

    public function setSex($sex)
    {
        if ((int)$sex > 0) {
            $this->sex = $sex;
        }
        return $this;
    }

    public function verify()
    {
        if (!empty($this->login) && !empty($this->email) && !empty($this->password) && !empty($this->birthday)) {
            return [
                'login' => $this->login,
                'email' => $this->email,
                'password' => $this->password,
                'birthday' => $this->birthday,
                'sex' => $this->sex,
            ];
        }
        return [];
    }
}

$rv = new RegisterValidator();
$values = $rv
    ->setLogin($login)
    ->setPassword($pass1, $pass2)
    ->setEmail($email)
    ->setBirthday($birthday)
    ->setSex($sex)
    ->verify();