<?php
namespace ILJ\Helper;

/**
 * The below line sets the `ticks` directive  to prevent timeout occurring on the frontend.
 * This is set for the complete file, @see https://www.php.net/manual/en/control-structures.declare.php
 * This is needed for {@link Timeout_Monitor_Layer} to work.
 */
declare(ticks=1000);

use ILJ\Core\Options;
use ILJ\Enumeration\TagExclusion;
use ILJ\Type\Ruleset;

/**
 * Replacement helper
 *
 * Handles the operations for removing unwanted elements from a content
 *
 * @package ILJ\Helper
 * @since   1.0.0
 */
class Replacement {

	const ILJ_FILTER_EXCLUDE_TEXT_PARTS = 'ilj_exclude_text_parts';

	/**
	 * Masks areas in the document, which should net get used for further linking anymore
	 *
	 * @since  1.0.0
	 * @param  string $content The content where the rules will get applied on
	 * @return Ruleset
	 */
	public static function mask(&$content) {
		$replace_ruleset = new Ruleset();

		$search_parts = array(
			// exclude all sensible html parts:
			'/(?<parts><a\b[^>]*>.*<\/a>)/sU',
			'/(?<parts><script\b[^>]*>.*<\/script>)/sU',
			'/(?<parts><style\b[^>]*>.*<\/style>)/sU',
		);

		$tag_exclusions = Options::getOption(\ILJ\Core\Options\NoLinkTags::getKey());

		if (is_array($tag_exclusions) && count($tag_exclusions)) {
			foreach ($tag_exclusions as $tag_exclusion) {
				$regex = TagExclusion::getRegex($tag_exclusion);

				if ($regex) {
					$search_parts[] = $regex;
				}
			}
		}

		/**
		 * Filters all parts of content that dont get used for applying link index
		 *
		 * @since 1.0.0
		 * @param array  $search_parts  All parts as regex that get excluded
		 */
		$search_parts = apply_filters(self::ILJ_FILTER_EXCLUDE_TEXT_PARTS, $search_parts);

		if (!is_array($search_parts)) {
			$search_parts = array();
		}

		$search_parts[] = '/(?<parts><.*>)/sU';
		foreach ($search_parts as $search_part) {
			preg_match_all($search_part, $content, $matches);
			if (isset($matches['parts'])) {
				foreach ($matches['parts'] as $part) {
					$link_id = ' ' . 'ilj_' . uniqid('', true) . ' ';
					$content = str_replace($part, $link_id, $content);
					$replace_ruleset->addRule($link_id, $part);
				}
			}
			unset($matches);
		}

		return $replace_ruleset;
	}
}