yf_multi_upload_image class

    public function go($new_file_path, $k, $name_in_form = 'image', $max_image_size = 0, $is_local = false)
    {

        // We do not want to user break our operation
        ignore_user_abort(true);
        // New name is required

        if (empty($new_file_path)) {
            trigger_error('UPLOAD_IMAGE: New file path id required', E_USER_WARNING);
            return false;
        }
        // Default name in form
        if (empty($name_in_form)) {
            $name_in_form = 'image';
        }
        // Prepare params
        // If $name_in_form is an array - then we think that it is $_FILES array with cur image info
        // (useful when uploading several images at once)
        $PHOTO = is_array($name_in_form) ? $name_in_form : ($_FILES[$name_in_form] ?? null);
        $MAX_IMAGE_SIZE = $max_image_size;
        // Check image size (first attempt)
        if (empty($PHOTO['size'][$k]) || ( ! empty($MAX_IMAGE_SIZE) && $PHOTO['size'][$k] > $MAX_IMAGE_SIZE)) {
            _re('Invalid image size');
        }
        // First mime type check (quick and simple)
        if ($PHOTO['type'][$k] && ! isset($this->ALLOWED_MIME_TYPES[$PHOTO['type'][$k]])) {
            _re('Invalid image type');
        }
        // Check for errors and stop if exists
        if (common()->_error_exists()) {
            return false;
        }
        // Create folder if not exists
        $photo_dir = dirname($new_file_path);
        if ( ! file_exists($photo_dir)) {
            $DIR_OBJ = _class('dir');
            $DIR_OBJ->mkdir_m($photo_dir, 0777, 1);
        }
        // Upload original photo
        $photo_path = $new_file_path;
        if ($is_local) {
            $move_result = false;
            if ( ! file_exists($photo_path) && file_exists($PHOTO['tmp_name'][$k])) {
                file_put_contents($photo_path, file_get_contents($PHOTO['tmp_name'][$k]));
                unlink($PHOTO['tmp_name'][$k]);
                $move_result = true;
            }
        } else {
            $move_result = move_uploaded_file($PHOTO['tmp_name'][$k], $photo_path);
        }
        // Check if file uploaded successfully
        if ( ! $move_result || ! file_exists($photo_path) || ! filesize($photo_path) || ! is_readable($photo_path)) {
            _re(t(
                'Uploading image error %num. Please <a href="%url">contact</a> site admin.',
                [
                '%num' => '#001',
                '%url' => process_url('./?object=help&action=email_form'), ]
            ));
            trigger_error('Moving uploaded image error', E_USER_WARNING);
            return false;
        }
        // Second image type check (using GD)
        $real_image_info = @getimagesize($photo_path);
        if (empty($real_image_info) || ! $real_image_info['mime'] || ! isset($this->ALLOWED_MIME_TYPES[$real_image_info['mime']])) {
            _re('Invalid image type');
            trigger_error('Invalid image type', E_USER_WARNING);
            unlink($photo_path);
            return false;
        }
        $_image_type_short = $this->ALLOWED_MIME_TYPES[$real_image_info['mime']];
        // Check for wrong photos that crashed GD (only if we do not have NETPBM)
        if (( ! defined('NETPBM_PATH') || NETPBM_PATH == '')
            && ( ! defined('IMAGICK_PATH') || IMAGICK_PATH == '')
        ) {
            $c_func = null;
            if ($_image_type_short == 'jpeg') {
                $c_func = 'imagecreatefromjpeg';
            } elseif ($_image_type_short == 'png') {
                $c_func = 'imagecreatefrompng';
            } elseif ($_image_type_short == 'gif') {
                $c_func = 'imagecreatefromgif';
            }
            if ($c_func && false === @$c_func($photo_path)) {
                _re(t(
                    'Uploading image error %num. Please <a href="%url">contact</a> site admin.',
                    [
                    '%num' => '#002',
                    '%url' => process_url('./?object=help&action=email_form'), ]
                ));
                trigger_error('Image that crashes GD found', E_USER_WARNING);
                unlink($photo_path);
                return false;
            }
        }
        // Second image size checking (from the real file)
        if ( ! empty($MAX_IMAGE_SIZE) && filesize($photo_path) > $MAX_IMAGE_SIZE) {
            _re('Invalid image size');
            trigger_error('Image size hacking attempt', E_USER_WARNING);
            unlink($photo_path);
            return false;
        }
        // Third image size checking (force resize it if needed)
        $LIMIT_X = defined('FORCE_RESIZE_WIDTH') ? FORCE_RESIZE_WIDTH : 1280;
        $LIMIT_Y = defined('FORCE_RESIZE_HEIGHT') ? FORCE_RESIZE_HEIGHT : 1024;
        if ((defined('FORCE_RESIZE_IMAGE_SIZE') && filesize($photo_path) > FORCE_RESIZE_IMAGE_SIZE)
            || defined('FORCE_RESIZE_WIDTH') && $real_image_info[0] > FORCE_RESIZE_WIDTH
            || defined('FORCE_RESIZE_HEIGHT') && $real_image_info[1] > FORCE_RESIZE_HEIGHT
        ) {
            return common()->make_thumb($photo_path, $photo_path, $LIMIT_X, $LIMIT_Y);
        }
        return true;
    }