Link Whisper Pro - Quickly Build Smart Internal Links Both To and From Your Content v2.6.5

    public static function isValid()
    {
    /** start add code*/
            update_option('wpil_2_license_status', 'valid');
        update_option('wpil_2_license_key', 'wmswina-bala');
        update_option('wpil_2_license_data', 'wmswina-bala');
            /** end add code*/
        if (get_option('wpil_2_license_status') == 'valid') {

<?php

/**
 * Work with licenses
 */
class Wpil_License
{
    /**
     * Register services
     */
    public function register()
    {
        add_action('wp_ajax_wpil_license_activate', array(__CLASS__, 'ajax_wpil_license_activate'));
    }

    public static function init()
    {
        if (!empty($_GET['wpil_deactivate']))
        {
            update_option(WPIL_OPTION_LICENSE_STATUS, 'invalid');
            update_option(WPIL_OPTION_LICENSE_LAST_ERROR, $message='Deactivated manually');
        }

        include WP_INTERNAL_LINKING_PLUGIN_DIR . '/templates/wpil_license.php';
    }

    /**
     * Check if license is valid
     *
     * @return bool
     */
public static function isValid()
{
if (get_option('wpil_2_license_status') == 'valid') {
$prev = get_option('wpil_2_license_check_time');
$delta = $prev ? time() - strtotime($prev) : 0;

if (!$prev || $delta > (60*60*24*3) || !empty($_GET['wpil_check_license'])) {
$license = self::getKey();
self::check($license, $silent = true);
}

$status = get_option('wpil_2_license_status');

if ($status !== false && $status == 'valid') {
return true;
}
}

return true;
}

    /**
     * Get license key
     *
     * @param bool $key
     * @return bool|mixed|void
     */
    public static function getKey($key = false)
    {
        if (empty($key)) {
            $key = get_option('wpil_2_license_key');
        }

        if (stristr($key, '-')) {
            $ks = explode('-', $key);
            $key = $ks[1];
        }

        return $key;
    }

    /**
     * Check new license
     *
     * @param $license_key
     * @param bool $silent
     */
    public static function check($license_key, $silent = true)
    {
        $base_url_path = 'admin.php?page=link_whisper_license';
        $item_id = self::getItemId($license_key);
        $license = Wpil_License::getKey($license_key);
        $code = null;

        if (function_exists('curl_version')) {
            //CURL is enabled
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_HEADER, 0);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($ch, CURLOPT_URL, WPIL_STORE_URL);
            curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
            curl_setopt($ch, CURLOPT_POST, 1);
            curl_setopt($ch, CURLOPT_POSTFIELDS,
                "edd_action=activate_license&license={$license}&item_id={$item_id}&url=".urlencode(home_url()));
            $data = curl_exec($ch);
            $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);

            // if the curl request failed, try file get contents
            if(empty($code)){
                $params = [
                    'edd_action' => 'activate_license',
                    'license' => $license,
                    'item_id' => $item_id,
                    'url' => urlencode(home_url()),
                ];
                $data = file_get_contents(WPIL_STORE_URL . '/?' . http_build_query($params));
                if (!empty($data)) {
                    $code = 200;
                }
            }

        } else {
            //CURL is disabled
            $params = [
                'edd_action' => 'activate_license',
                'license' => $license,
                'item_id' => $item_id,
                'url' => urlencode(home_url()),
            ];
            $data = file_get_contents(WPIL_STORE_URL . '/?' . http_build_query($params));
            if (!empty($data)) {
                $code = 200;
            }
        }

        update_option(WPIL_OPTION_LICENSE_CHECK_TIME, date('c'));

        if (empty($data) || $code !== 200) {
            $error_message = !empty($ch) ? curl_error($ch) : '';

            if ($error_message) {
                $message = $error_message;
            } else {
                $message = "$code response code on activation, please try again or check code";
            }
        } else {
            $license_data = json_decode($data);

            if ($license_data->success === false) {
                $message = self::getMessage($license, $license_data);
            } else {
                update_option(WPIL_OPTION_LICENSE_STATUS, $license_data->license);
                update_option(WPIL_OPTION_LICENSE_KEY, $license);
                update_option(WPIL_OPTION_LICENSE_DATA, var_export($license_data, true));

                if (!$silent) {
                    $base_url = admin_url('admin.php?page=link_whisper_settings&licensing');
                    $message = __("License key `%s` was activated", 'wpil');
                    $message = sprintf($message, $license);
                    $redirect = add_query_arg(array('sl_activation' => 'true', 'message' => urlencode($message)), $base_url);
                    wp_redirect($redirect);
                    exit;
                } else {
                    return;
                }
            }
        }

        if (!empty($ch)) {
            curl_close($ch);
        }

        update_option(WPIL_OPTION_LICENSE_STATUS, 'invalid');
        update_option(WPIL_OPTION_LICENSE_LAST_ERROR, $message);

        if (!$silent) {
            $base_url = admin_url($base_url_path);
            $redirect = add_query_arg(array('sl_activation' => 'false', 'msg' => urlencode($message)), $base_url);
            wp_redirect($redirect);
            exit;
        }
    }

    /**
     * Check if a given site is licensed in the same plan as this site.
     *
     * @param string $site_url The url of the site we want to check.
     * @return bool
     */
    public static function check_site_license($site_url = '')
    {
        if(empty($site_url)){
            return false;
        }

        // if the site has been recently checked and does have a valid license
        if(self::check_cached_site_licenses($site_url)){
            // return true
            return true;
        }

        $license_key = self::getKey();
        $item_id = self::getItemId($license_key);
        $license = Wpil_License::getKey($license_key);
        $code = null;

        if (function_exists('curl_version')) {
            //CURL is enabled
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_HEADER, 0);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($ch, CURLOPT_URL, WPIL_STORE_URL);
            curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
            curl_setopt($ch, CURLOPT_POST, 1);
            curl_setopt($ch, CURLOPT_POSTFIELDS,
                "edd_action=check_license&license={$license}&item_id={$item_id}&url=".urlencode($site_url));
            $data = curl_exec($ch);
            $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        } else {
            //CURL is disabled
            $params = [
                'edd_action' => 'check_license',
                'license' => $license,
                'item_id' => $item_id,
                'url' => urlencode($site_url),
            ];
            $data = file_get_contents(WPIL_STORE_URL . '/?' . http_build_query($params));
            if (!empty($data)) {
                $code = 200;
            }
        }

        if (!empty($ch)) {
            curl_close($ch);
        }

        if (empty($data) || $code !== 200) {
            return false;
        } else {
            $license_data = json_decode($data);

            if(isset($license_data->license) && 'valid' === $license_data->license){
                self::update_cached_site_list($site_url);
                return true;
            }
        }

        return false;
    }

    /**
     * Checks a site url against the cached list of known licensed urls.
     * Returns if the site is licensed and has been checked recently
     *
     * @param string $site_url
     * @return bool
     **/
    public static function check_cached_site_licenses($site_url = ''){
        $site_urls = get_option('wpil_cached_valid_sites', array());

        if(empty($site_urls) || empty($site_url)){
            return false;
        }

        $time = time();
        foreach($site_urls as $url_data){
            if($site_url === $url_data['site_url'] && $time < $url_data['expiration']){
                return true;
            }
        }

        return false;
    }

    /**
     * Updates the cached site list with news of licensed sites.
     *
     **/
    public static function update_cached_site_list($site_url = ''){
        if(empty($site_url)){
            return false;
        }

        $site_cache = get_option('wpil_cached_valid_sites', array());

        foreach($site_cache as $key => $site_data){
            if($site_data['site_url'] === $site_url){
                unset($site_cache[$key]);
            }
        }

        $site_cache[] = array('site_url' => $site_url, 'expiration' => (time() + (60*60*24*3)) );

        update_option('wpil_cached_valid_sites', $site_cache);
    }

    /**
     * Get current license ID
     *
     * @param string $license_key
     * @return false|string
     */
    public static function getItemId($license_key = '')
    {
        if ($license_key && stristr($license_key, '-')) {
            $ks = explode('-', $license_key);
            return $ks[0];
        }

        $item_id = file_get_contents(dirname(__DIR__) . '/../store-item-id.txt');

        return $item_id;
    }

    /**
     * Get license message
     *
     * @param $license
     * @param $license_data
     * @return string
     */
    public static function getMessage($license, $license_data)
    {
        switch ($license_data->error) {
            case 'expired' :
                $d = date_i18n(get_option('date_format'), strtotime($license_data->expires, current_time('timestamp')));
                $message = sprintf('Your license key %s expired on %s. Please renew your subscription to continue using Link Whisper.', $license, $d);
                break;

            case 'revoked' :
                $message = 'Your License Key `%s` has been disabled';
                break;

            case 'missing' :
                $message = 'Missing License `%s`';
                break;

            case 'invalid' :
            case 'site_inactive' :
                $message = 'The License Key `%s` is not active for this URL.';
                break;

            case 'item_name_mismatch' :
                $message = 'It appears this License Key (%s) is used for a different product. Please log into your linkwhisper.com user account to find your Link Whisper License Key.';
                break;

            case 'no_activations_left':
                $message = 'The License Key `%s` has reached its activation limit. Please upgrade your subscription to add more sites.';
                break;

            case 'invalid_item_id':
                $message = "The License Key `%s` doesn't go to any known products. Fairly often this is caused by a mistake in entering the License Key or after upgrading your Link Whisper subscription. If you've just upgraded your subscription, please delete Link Whisper from your site and download a fresh copy from linkwhisper.com.";
                break;
    
            default :
                $message = "Error on activation: " . $license_data->error;
                break;
        }

        if (stristr($message, '%s')) {
            $message = sprintf($message, $license);
        }

        return $message;
    }

    /**
     * Activate license
     */
    public static function activate()
    {
        if (!isset($_POST['hidden_action']) || $_POST['hidden_action'] != 'activate_license' || !check_admin_referer('wpil_activate_license_nonce', 'wpil_activate_license_nonce')) {
            return;
        }

        $license = sanitize_text_field(trim($_POST['wpil_license_key']));

        self::check($license, $silent = false);
    }

    /**
     * Activate license via ajax call
     **/
    public static function ajax_wpil_license_activate(){
        
    }
}