gruene-seele/dev/dhl-for-woocommerce/includes/pr-dhl-api/class-pr-dhl-api-auth-rest.php

<?php

if (! defined('ABSPATH')) {
    exit;
} // Exit if accessed directly

// Singleton API connection class
class PR_DHL_API_Auth_REST
{
    /**
     * define Auth API endpoint
     */
    const PR_DHL_REST_AUTH_END_POINT = '/account/v1/auth/accesstoken';

    /**
     * @var string
     */
    protected $access_token;

    /**
     * @var time
     */
    protected $token_expires = 0;

    /**
     * @var string
     */
    protected $token_type;

    /**
     * @var string
     */
    protected $token_scope;

    /**
     * @var string
     */
    private $client_id;

    /**
     * @var string
     */
    private $client_secret;

    /**
     * @var PR_DHL_API_Auth_REST
     */
    private static $_instance; // The single instance

    /**
     * constructor.
     */
    private function __construct() {}

    // Magic method clone is empty to prevent duplication of connection
    private function __clone() {}

    // Stopping unserialize of object
    public function __wakeup() {}

    public static function get_instance()
    {

        if ((! self::$_instance)) {
            self::$_instance = new self;
        }

        return self::$_instance;
    }

    /**
     * @return string
     */
    public function get_access_token($client_id, $client_secret)
    {

        // Load transient token
        $this->get_saved_token($client_id, $client_secret);

        if ($this->is_access_token_empty()) {
            try {

                $this->request_access_token($client_id, $client_secret);

            } catch (Exception $e) {
                throw $e;
            }
        }

        return $this->access_token;
    }

    public function delete_access_token()
    {
        PR_DHL()->log_msg('Delete Transient - Access Token');
        delete_transient('_dhl_auth_token_rest');
    }

    /**
     * @param  string  $access_token
     */
    protected function set_access_token($access_token, $expires_in = 0, $token_type = '', $token_scope = '')
    {

        if (! empty($expires_in)) {
            // $token_expires = time() + $expires_in;
            set_transient('_dhl_auth_token_rest', $access_token, $expires_in);
            PR_DHL()->log_msg('Set Transient - Access Token');
        }

        $this->access_token = $access_token;
        $this->token_type = $token_type;
        $this->token_scope = $token_scope;
    }

    private function get_saved_token($client_id, $client_secret)
    {

        // if( $this->is_key_match($client_id, $client_secret) ) {
        // TRANSIENT MIGHT BE BEING USED IF KEY AND SECRET ARE NEW, EDGE CASE SO MIGHT BE OK!
        $transient_token = get_transient('_dhl_auth_token_rest');
        PR_DHL()->log_msg('Get Transient - Access Token');
        $this->set_access_token($transient_token);

        // }
    }

    /**
     * @return bool
     */
    protected function is_access_token_empty()
    {
        return empty($this->access_token);
    }

    /**
     * Get the signed URL.
     * The signed URL is fetched by doing an OAuth request.
     *
     *
     * @return string
     *
     * @throws Exception
     */
    protected function request_access_token($client_id, $client_secret)
    {
        $this->client_id = $client_id;
        $this->client_secret = $client_secret;

        if (empty($this->client_id) || empty($this->client_secret)) {
            throw new Exception(esc_html__('The "Cliend Id" or "Client Secret" is empty.', 'dhl-for-woocommerce'));
        }

        $wp_request_headers = [
            'Authorization' => 'Basic '.base64_encode($this->client_id.':'.$this->client_secret),
        ];

        $wp_request_url = PR_DHL()->get_api_url().self::PR_DHL_REST_AUTH_END_POINT;

        PR_DHL()->log_msg('Authorization URL: '.$wp_request_url);

        $wp_auth_response = wp_remote_get(
            $wp_request_url,
            ['headers' => $wp_request_headers]
        );

        $response_code = wp_remote_retrieve_response_code($wp_auth_response);
        $response_body = json_decode(wp_remote_retrieve_body($wp_auth_response));

        PR_DHL()->log_msg('Authorization Response: '.$response_code);

        switch ($response_code) {
            case '200':
                $this->set_access_token($response_body->access_token, $response_body->expires_in, $response_body->token_type, $response_body->scope);
                break;
            case '401':
            default:
                throw new Exception(esc_html__('Authentication failed: Please, check client ID and secret in the DHL shipping settings', 'dhl-for-woocommerce'));
                break;
        }
    }

    public function is_key_match($client_id, $client_secret)
    {
        if (($this->client_id == $client_id) && ($this->client_secret == $client_secret)) {
            return true;
        } else {
            return false;
        }
    }
}