/**
 * Retrieve HTTP Headers from URL.
 *
 * @since 1.5.1
 *
 * @param string $url        URL to retrieve HTTP headers from.
 * @param bool   $deprecated Not Used.
 * @return bool|string False on failure, headers on success.
 */
function wp_get_http_headers($url, $deprecated = false)
{
    if (!empty($deprecated)) {
        _deprecated_argument(__FUNCTION__, '2.7');
    }
    $response = wp_safe_remote_head($url);
    if (is_wp_error($response)) {
        return false;
    }
    return wp_remote_retrieve_headers($response);
}

/**
 * Finds a pingback server URI based on the given URL.
 *
 * Checks the HTML for the rel="pingback" link and x-pingback headers. It does
 * a check for the x-pingback headers first and returns that, if available. The
 * check for the rel="pingback" has more overhead than just the header.
 *
 * @since 1.5.0
 *
 * @param string $url URL to ping.
 * @param int $deprecated Not Used.
 * @return false|string False on failure, string containing URI on success.
 */
function discover_pingback_server_uri($url, $deprecated = '')
{
    if (!empty($deprecated)) {
        _deprecated_argument(__FUNCTION__, '2.7');
    }
    $pingback_str_dquote = 'rel="pingback"';
    $pingback_str_squote = 'rel=\'pingback\'';
    /** @todo Should use Filter Extension or custom preg_match instead. */
    $parsed_url = parse_url($url);
    if (!isset($parsed_url['host'])) {
        // Not an URL. This should never happen.
        return false;
    }
    //Do not search for a pingback server on our own uploads
    $uploads_dir = wp_upload_dir();
    if (0 === strpos($url, $uploads_dir['baseurl'])) {
        return false;
    }
    $response = wp_safe_remote_head($url, array('timeout' => 2, 'httpversion' => '1.0'));
    if (is_wp_error($response)) {
        return false;
    }
    if (wp_remote_retrieve_header($response, 'x-pingback')) {
        return wp_remote_retrieve_header($response, 'x-pingback');
    }
    // Not an (x)html, sgml, or xml page, no use going further.
    if (preg_match('#(image|audio|video|model)/#is', wp_remote_retrieve_header($response, 'content-type'))) {
        return false;
    }
    // Now do a GET since we're going to look in the html headers (and we're sure it's not a binary file)
    $response = wp_safe_remote_get($url, array('timeout' => 2, 'httpversion' => '1.0'));
    if (is_wp_error($response)) {
        return false;
    }
    $contents = wp_remote_retrieve_body($response);
    $pingback_link_offset_dquote = strpos($contents, $pingback_str_dquote);
    $pingback_link_offset_squote = strpos($contents, $pingback_str_squote);
    if ($pingback_link_offset_dquote || $pingback_link_offset_squote) {
        $quote = $pingback_link_offset_dquote ? '"' : '\'';
        $pingback_link_offset = $quote == '"' ? $pingback_link_offset_dquote : $pingback_link_offset_squote;
        $pingback_href_pos = @strpos($contents, 'href=', $pingback_link_offset);
        $pingback_href_start = $pingback_href_pos + 6;
        $pingback_href_end = @strpos($contents, $quote, $pingback_href_start);
        $pingback_server_url_len = $pingback_href_end - $pingback_href_start;
        $pingback_server_url = substr($contents, $pingback_href_start, $pingback_server_url_len);
        // We may find rel="pingback" but an incomplete pingback URL
        if ($pingback_server_url_len > 0) {
            // We got it!
            return $pingback_server_url;
        }
    }
    return false;
}

 /**
  * @param $filename
  *
  * @return bool
  */
 private function validate_filename($filename)
 {
     // check if file exists
     $url = WC_BooXtream::storedfilesurl . sanitize_file_name($filename) . '?exists';
     // Set authentication
     $accountkey = $this->settings->accountkey;
     $loginname = $this->settings->accounts[$accountkey]['loginname'];
     $args = array('headers' => array('Authorization' => 'Basic ' . base64_encode($loginname . ':' . $accountkey)));
     $response = wp_safe_remote_head($url, $args);
     if ($response['response']['code'] !== 200) {
         return false;
     }
     return true;
 }

 /**
  * Validate post links
  *
  * @since   0.1.0
  * @change  0.7.1
  *
  * @hook    array  spcl_acceptable_protocols
  *
  * @param   intval  $id  Post ID
  */
 public static function validate_links($id)
 {
     /* No PostID? */
     if (empty($id)) {
         return;
     }
     /* Get post data */
     $post = get_post($id);
     /* Post incomplete? */
     if (empty($post) or empty($post->post_content)) {
         return;
     }
     /* Extract urls */
     if (!($urls = wp_extract_urls($post->post_content))) {
         return;
     }
     /* Init */
     $found = array();
     /* Loop the urls */
     foreach ($urls as $url) {
         /* Acceptable protocols filter */
         $acceptable_protocols = (array) apply_filters('spcl_acceptable_protocols', array('http', 'https'));
         /* Scheme check */
         if (!in_array(parse_url($url, PHP_URL_SCHEME), $acceptable_protocols)) {
             continue;
         }
         /* Fragment check */
         if ($hash = parse_url($url, PHP_URL_FRAGMENT)) {
             $url = str_replace('#' . $hash, '', $url);
         }
         /* URL sanitization */
         $url = esc_url_raw($url, $acceptable_protocols);
         /* Skip URL */
         if (empty($url)) {
             continue;
         }
         /* Ping */
         $response = wp_safe_remote_head($url);
         /* Error? */
         if (is_wp_error($response)) {
             $found[] = array('url' => $url, 'error' => $response->get_error_message());
             /* Respronse code */
         } else {
             /* Status code */
             $code = (int) wp_remote_retrieve_response_code($response);
             /* Handle error codes */
             if ($code >= 400 && $code != 405) {
                 $found[] = array('url' => $url, 'error' => sprintf('Status Code %d', $code));
             }
         }
     }
     /* No items? */
     if (empty($found)) {
         return;
     }
     /* Cache the result */
     set_transient(self::_transient_hash(), $found, 60 * 30);
 }

/**
 * Handles form submission on save. Redirects if save is successful, otherwise sets an error message as a cmb property
 *
 * @return void
 */
function ot_handle_frontend_new_post_form_submission()
{
    // If no form submission, bail
    if (empty($_POST) || !isset($_POST['submit-cmb'], $_POST['object_id'])) {
        return false;
    }
    // Get CMB2 metabox object
    $cmb = ot_frontend_cmb2_get();
    $post_data = array();
    // Get our shortcode attributes and set them as our initial post_data args
    if (isset($_POST['atts'])) {
        foreach ((array) $_POST['atts'] as $key => $value) {
            $post_data[$key] = sanitize_text_field($value);
        }
        unset($_POST['atts']);
    }
    // Check security nonce
    if (!isset($_POST[$cmb->nonce()]) || !wp_verify_nonce($_POST[$cmb->nonce()], $cmb->nonce())) {
        return $cmb->prop('submission_error', new WP_Error('security_fail', __('Security check failed.')));
    }
    // Check title submitted
    if (empty($_POST['_ot_bv_link_submit_link'])) {
        return $cmb->prop('submission_error', new WP_Error('post_data_missing', __('New post requires a title.')));
    }
    // And that the title is not the default title
    if ($cmb->get_field('_ot_bv_link_submit_link')->default() == $_POST['_ot_bv_link_submit_link']) {
        return $cmb->prop('submission_error', new WP_Error('post_data_missing', __('Please enter a new title.')));
    }
    // Anti-spam honeypot - reject any submissions with this field isn't empty
    if (!empty($_POST['_ot_bv_link_submit_email_honeypot'])) {
        return $cmb->prop('submission_error', new WP_Error('post_data_missing', __('Sorry, we can\'t accept this submission.')));
    }
    /**
     * Fetch sanitized values
     */
    $sanitized_values = $cmb->get_sanitized_values($_POST);
    // Check the link is valid
    $url = $sanitized_values['_ot_bv_link_submit_link'];
    $response = wp_safe_remote_head($url, array('timeout' => 5));
    $accepted_status_codes = array(200, 301, 302, 404);
    if ($_POST['_ot_bv_link_submit_link'] && !in_array(wp_remote_retrieve_response_code($response), $accepted_status_codes)) {
        return $cmb->prop('submission_error', new WP_Error('invalid_url', __('That URL doesn\'t seem to exist or is currently down, please try again.')));
    }
    // Set the Title
    $get_title_from_url = get_title_from_url($url);
    // Set our post data arguments
    $post_data['post_title'] = $get_title_from_url;
    unset($get_title_from_url);
    $post_data['post_content'] = $sanitized_values['_ot_bv_link_submit_reason'];
    unset($sanitized_values['_ot_bv_link_submit_reason']);
    // select the category from the theme customiser
    $bv_links_category = get_theme_mod('ot_bv_user_selected_links_cat');
    $post_data['post_category'] = array($bv_links_category);
    $post_data['tax_input'] = array('post_format' => array('post-format-link'));
    // Create the new post
    $new_submission_id = wp_insert_post($post_data, true);
    // If we hit a snag, update the user
    if (is_wp_error($new_submission_id)) {
        return $cmb->prop('submission_error', $new_submission_id);
    }
    // Loop through remaining (sanitized) data, and save to post-meta
    foreach ($sanitized_values as $key => $value) {
        if (is_array($value)) {
            $value = array_filter($value);
            if (!empty($value)) {
                update_post_meta($new_submission_id, $key, $value);
            }
        } else {
            update_post_meta($new_submission_id, $key, $value);
        }
    }
    /*
     * Redirect back to the form page with a query variable with the new post ID.
     * This will help double-submissions with browser refreshes
     */
    wp_redirect(esc_url_raw(add_query_arg('post_submitted', $new_submission_id)));
    exit;
}