<?php
/**
 * Automatic local download external files
 *
 * @package     Joomla.Plugin
 * @subpackage  System.Jtaldef
 *
 * @author      Guido De Gobbis <support@joomtools.de>
 * @copyright   JoomTools.de - All rights reserved.
 * @license     GNU General Public License version 3 or later
 */

namespace Jtaldef\Service;

defined('_JEXEC') or die;

use Jtaldef\Helper\JtaldefHelper;

/**
 * Download and save external fonts like Google Fonts
 *
 * @since  2.0.0
 */
class ParseCss
{
    /**
     * Description
     *
     * @param   string   $value   Link to content or the content itself to parse.
     * @param   boolean  $isPath  True if it is a path to a local file or false for content like <style/>.
     *
     * @return  boolean|string  False if no font info is set in the query else the local path to the css file.
     * @throws  \Exception
     *
     * @since   2.0.0
     */
    public function getNewFileContent($value, $isPath = true)
    {
        $file    = null;
        $content = $value;

        if ($isPath) {
            $file = JPATH_ROOT . '/' . $value;

            if (file_exists($file)) {
                $content = file_get_contents($file);
            }

            if (empty($content) || !is_string($content)) {
                return false;
            }
        }

        $content = JtaldefHelper::cleanContent($content);
        $matches = $this->getFontImports($content);

        if (empty($matches) || $matches['onlyInternal']) {
            return false;
        }

        unset($matches['onlyInternal']);

        foreach ($matches as $imports) {
            $service = JtaldefHelper::getServiceByLink($imports['fontUrl']);

            if ($service) {
                $localFontUrl = JtaldefHelper::getNewFileContentLink($imports['fontUrl'], $service);
            }

            if (!$service) {
                $localFontUrl = JtaldefHelper::replaceRelativeToAbsolutePath($imports['fontUrl'], $file);
            }

            if ($localFontUrl !== false) {
                $newImport = "@import '" . $localFontUrl . "';";

                $imports['search'] = array_unique($imports['search'], SORT_REGULAR);

                $content = $newImport . PHP_EOL . str_replace($imports['search'], '', $content);
            }
        }

        $content = $this->replaceRelativePath($content, $file);

        return $content;
    }

    /**
     * Search for font-face blocks to parse local relative paths
     *
     * @param   string  $content  The content to be scanned
     * @param   string  $file     Absolute path to the actual file
     *
     * @return  string
     *
     * @since   2.0.0
     */
    public function replaceRelativePath($content, $file)
    {
        $replacements = array();

        // Check for CSS with images to replace the path with the new one
        if (preg_match_all('#url\(([^)]+?)\)#Us', $content, $paths, PREG_SET_ORDER)) {
            foreach ($paths as $path) {
                $regex   = array('"', "'");
                $path[1] = trim(str_replace($regex, '', $path[1]));

                if (empty($path[1]) || JtaldefHelper::isExternalUrl($path[1])) {
                    continue;
                }

                $newPath = JtaldefHelper::replaceRelativeToAbsolutePath($path[1], $file);

                if (false === $newPath) {
                    continue;
                }

                $replacements['search'][md5($path[1])]  = $path[1];
                $replacements['replace'][md5($path[1])] = $newPath;
            }

            if (!empty($replacements)) {
                $content = str_replace($replacements['search'], $replacements['replace'], $content);
            }
        }

        return $content;
    }

    /**
     * Search for fonts imports
     *
     * @param   string  $content  The content to be scanned
     *
     * @return  array
     *
     * @since   2.0.0
     */
    public function getFontImports($content)
    {
        $return       = array();
        $onlyInternal = true;

        // Check for Google Font imports - benchmarked regex
        if (preg_match_all('#(?<match>@import\s+(?:[^;]+?)?((?:url\()?([("\'])(?<url>[^)("\']+?)(?:\)|\\3\)?));)#Um', $content, $imports, PREG_SET_ORDER)) {
            foreach ($imports as $match) {
                $fontUrl   = str_replace(array('url(', ')', '"', "'"), '', $match['url']);
                $fontUrl   = trim($fontUrl);
                $fontUrlId = md5($fontUrl);

                $fontUrl = JtaldefHelper::normalizeUrl($fontUrl);

                $return[$fontUrlId]['fontUrl']  = $fontUrl;
                $return[$fontUrlId]['search'][] = $match['match'];

                if (JtaldefHelper::isExternalUrl($fontUrl)) {
                    $onlyInternal = false;
                }
            }

            $return['onlyInternal'] = $onlyInternal;
        }

        return $return;
    }
}