<?php

/**
 * Class RegistrationModel
 *
 * Everything registration-related happens here.
 */
class RegistrationModel
{
    /**
     * Handles the entire registration process for DEFAULT users (not for people who register with
     * 3rd party services, like facebook) and creates a new user in the database if everything is fine
     *
     * @return boolean Gives back the success status of the registration
     */
    public static function registerNewUser($isAdmin = false)
    {
        $user_name = strip_tags(Request::post('user_name'));
        $user_email = strip_tags(Request::post('user_email'));
        $user_password_new = Request::post('user_password_new');
        $user_password_repeat = $user_password_new;

        $valid = true;
        if (!self::validateRecaptcha()) { $valid = false; }
        if (!self::validateUserName($user_name)) { $valid = false; }
        if (!self::validateUserEmail($user_email, $user_email)) { $valid = false; }
        if (!self::validateUserPassword($user_password_new, $user_password_repeat)) { $valid = false; }
        if (!$valid) { return false; }

        // hash the password
        $user_password_hash = password_hash($user_password_new, PASSWORD_DEFAULT);

        $return = true;
        if (UserModel::doesUsernameAlreadyExist($user_name)) {
            Session::add('feedback_negative', Text::get('FEEDBACK_USERNAME_ALREADY_TAKEN'));
            $return = false;
        }
        if (UserModel::doesEmailAlreadyExist($user_email)) {
            Session::add('feedback_negative', Text::get('FEEDBACK_USER_EMAIL_ALREADY_TAKEN'));
            $return = false;
        }
        if (!$return) return false;

        // directly activate user: set empty activation hash
        $user_activation_hash = null;

        // write user data to database
        if (!self::writeNewUserToDatabase($user_name, $user_password_hash, $user_email, time(), $user_activation_hash)) {
            Session::add('feedback_negative', Text::get('FEEDBACK_ACCOUNT_CREATION_FAILED'));
            return false;
        }

        Session::add('feedback_positive', Text::get('FEEDBACK_ACCOUNT_SUCCESSFULLY_CREATED'));
        return true;
    }

    /**
     * Validates the registration input
     *
     * @param $user_name
     * @param $user_password_new
     * @param $user_email
     *
     * @return bool
     */
    public static function registrationInputValidation($user_name, $user_password_new, $user_email)
    {
        $return = true;

        if (empty($user_name) || empty($user_password_new) || empty($user_email)) {
            Session::add('feedback_negative', Text::get('FEEDBACK_FIELDS_EMPTY'));
            $return = false;
        }

        return $return;
    }

    public static function validateRecaptcha()
    {
        $recaptcha_response = Request::post('g-recaptcha-response');

        if (empty($recaptcha_response)) {
            Session::add('feedback_negative', 'reCAPTCHA verification failed. Please try again.');
            return false;
        }

        $secret_key = Config::get('RECAPTCHA_SECRET_KEY');
        $verify_url = 'https://www.google.com/recaptcha/api/siteverify';

        $response = file_get_contents($verify_url . '?secret=' . $secret_key . '&response=' . $recaptcha_response);
        $response_data = json_decode($response);

        if (!$response_data->success) {
            Session::add('feedback_negative', 'reCAPTCHA verification failed. Please try again.');
            return false;
        }

        // v3 returns a score from 0.0 to 1.0 (1.0 = likely human, 0.0 = likely bot)
        if (isset($response_data->score) && $response_data->score < 0.5) {
            Session::add('feedback_negative', 'Registration blocked due to suspicious activity.');
            return false;
        }

        return true;
    }

    public static function validateUserName($user_name)
    {
        if (empty($user_name)) {
            Session::add('feedback_negative', Text::get('FEEDBACK_USERNAME_FIELD_EMPTY'));
            return false;
        }

        if (!preg_match('/^[a-zA-Z0-9]{2,64}$/', $user_name)) {
            Session::add('feedback_negative', Text::get('FEEDBACK_USERNAME_DOES_NOT_FIT_PATTERN'));
            return false;
        }

        return true;
    }

    /**
     * Validates the email
     *
     * @param $user_email
     * @param $user_email_repeat
     * @return bool
     */
    public static function validateUserEmail($user_email, $user_email_repeat)
    {
        if (empty($user_email)) {
            Session::add('feedback_negative', Text::get('FEEDBACK_EMAIL_FIELD_EMPTY'));
            return false;
        }

        if ($user_email !== $user_email_repeat) {
            Session::add('feedback_negative', Text::get('FEEDBACK_EMAIL_REPEAT_WRONG'));
            return false;
        }

        // validate the email with PHP's internal filter
        // side-fact: Max length seems to be 254 chars
        // @see http://stackoverflow.com/questions/386294/what-is-the-maximum-length-of-a-valid-email-address
        if (!filter_var($user_email, FILTER_VALIDATE_EMAIL)) {
            Session::add('feedback_negative', Text::get('FEEDBACK_EMAIL_DOES_NOT_FIT_PATTERN'));
            return false;
        }

        return true;
    }

    /**
     * Validates the password
     *
     * @param $user_password_new
     * @param $user_password_repeat
     * @return bool
     */
    public static function validateUserPassword($user_password_new, $user_password_repeat)
    {
        if (empty($user_password_new) OR empty($user_password_repeat)) {
            Session::add('feedback_negative', Text::get('FEEDBACK_PASSWORD_FIELD_EMPTY'));
            return false;
        }

        if ($user_password_new !== $user_password_repeat) {
            Session::add('feedback_negative', Text::get('FEEDBACK_PASSWORD_REPEAT_WRONG'));
            return false;
        }

        // no minimum length restriction
        return true;
    }

    /**
     * Writes the new user's data to the database
     *
     * @param $user_name
     * @param $user_password_hash
     * @param $user_email
     * @param $user_creation_timestamp
     * @param $user_activation_hash
     *
     * @return bool
     */
    public static function writeNewUserToDatabase($user_name, $user_password_hash, $user_email, $user_creation_timestamp, $user_activation_hash)
    {
        $database = DatabaseFactory::getFactory()->getConnection();

        // write new users data into database; set user_active=1 and user_activation_hash to provided value (can be null)
        $sql = "INSERT INTO users (user_name, user_password_hash, user_email, user_creation_timestamp, user_activation_hash, user_provider_type, user_active)
                    VALUES (:user_name, :user_password_hash, :user_email, :user_creation_timestamp, :user_activation_hash, :user_provider_type, 1)";
        $query = $database->prepare($sql);
        try {
            $query->execute(array(
                ':user_name' => $user_name,
                ':user_password_hash' => $user_password_hash,
                ':user_email' => $user_email,
                ':user_creation_timestamp' => $user_creation_timestamp,
                ':user_activation_hash' => $user_activation_hash,
                ':user_provider_type' => 'DEFAULT'
            ));
        } catch (PDOException $e) {
            // only one feedback message on failure
            return false;
        }
        $count =  $query->rowCount();
        if ($count == 1) {
            return true;
        }

        return false;
    }

    /**
     * Deletes the user from users table. Currently used to rollback a registration when verification mail sending
     * was not successful.
     *
     * @param $user_id
     */
    public static function rollbackRegistrationByUserId($user_id)
    {
        $database = DatabaseFactory::getFactory()->getConnection();

        $query = $database->prepare("DELETE FROM users WHERE user_id = :user_id");
        $query->execute(array(':user_id' => $user_id));
    }

    /**
     * Sends the verification email (to confirm the account).
     * The construction of the mail $body looks weird at first, but it's really just a simple string.
     *
     * @param int $user_id user's id
     * @param string $user_email user's email
     * @param string $user_activation_hash user's mail verification hash string
     *
     * @return boolean gives back true if mail has been sent, gives back false if no mail could been sent
     */
    public static function sendVerificationEmail($user_id, $user_email, $user_activation_hash)
    {
        $body = Config::get('EMAIL_VERIFICATION_CONTENT') . Config::get('URL') . Config::get('EMAIL_VERIFICATION_URL')
                . '/' . urlencode($user_id) . '/' . urlencode($user_activation_hash);

        $mail = new Mail;
        $mail_sent = $mail->sendMail($user_email, Config::get('EMAIL_VERIFICATION_FROM_EMAIL'),
            Config::get('EMAIL_VERIFICATION_FROM_NAME'), Config::get('EMAIL_VERIFICATION_SUBJECT'), $body
        );

        if ($mail_sent) {
            Session::add('feedback_positive', Text::get('FEEDBACK_VERIFICATION_MAIL_SENDING_SUCCESSFUL'));
            return true;
        } else {
            Session::add('feedback_negative', Text::get('FEEDBACK_VERIFICATION_MAIL_SENDING_ERROR') . $mail->getError() );
            return false;
        }
    }

    /**
     * checks the email/verification code combination and set the user's activation status to true in the database
     *
     * @param int $user_id user id
     * @param string $user_activation_verification_code verification token
     *
     * @return bool success status
     */
    public static function verifyNewUser($user_id, $user_activation_verification_code)
    {
        $database = DatabaseFactory::getFactory()->getConnection();

        $sql = "UPDATE users SET user_active = 1, user_activation_hash = NULL
                WHERE user_id = :user_id AND user_activation_hash = :user_activation_hash LIMIT 1";
        $query = $database->prepare($sql);
        $query->execute(array(':user_id' => $user_id, ':user_activation_hash' => $user_activation_verification_code));

        if ($query->rowCount() == 1) {
            Session::add('feedback_positive', Text::get('FEEDBACK_ACCOUNT_ACTIVATION_SUCCESSFUL'));
            return true;
        }

        Session::add('feedback_negative', Text::get('FEEDBACK_ACCOUNT_ACTIVATION_FAILED'));
        return false;
    }
}