From 85bc65c547348043e7960bd2c5b4613e5f9453c3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bartosz=20Dziewo=C5=84ski?= <matma.rex@gmail.com>
Date: Sat, 29 Apr 2023 17:07:54 +0200
Subject: [PATCH 4/4] Use HtmlHelper::modifyElements() instead of regexps to
 modify links

This may be slower, but the result of this method is already cached,
and it is more correct (e.g. internal links with fragments were
previously handled incorrectly).

Change-Id: I323e80b777b63425989f67f36a7e4d9a34fdaf6b
---
 includes/DoubleWiki.php | 69 +++++++++++++++++++++++++++++------------
 1 file changed, 49 insertions(+), 20 deletions(-)

diff --git a/includes/DoubleWiki.php b/includes/DoubleWiki.php
index 92ccc13..d73db7c 100644
--- a/includes/DoubleWiki.php
+++ b/includes/DoubleWiki.php
@@ -24,6 +24,7 @@ use Language;
 use MediaWiki\Hook\BeforePageDisplayHook;
 use MediaWiki\Hook\OutputPageBeforeHTMLHook;
 use MediaWiki\Html\Html;
+use MediaWiki\Html\HtmlHelper;
 use MediaWiki\Http\HttpRequestFactory;
 use MediaWiki\Languages\LanguageFactory;
 use MediaWiki\Languages\LanguageNameUtils;
@@ -31,6 +32,7 @@ use OutputPage;
 use Skin;
 use Title;
 use WANObjectCache;
+use Wikimedia\RemexHtml\Serializer\SerializerNode;
 
 class DoubleWiki implements OutputPageBeforeHTMLHook, BeforePageDisplayHook {
 
@@ -134,33 +136,60 @@ class DoubleWiki implements OutputPageBeforeHTMLHook, BeforePageDisplayHook {
 	 */
 	private function getMangledTextAndTranslation( string $text, string $translation, string $matchLangCode ): array {
 		// add prefixes to internal links, in order to prevent duplicates
-		$translation = preg_replace(
-			"/<a href=\"#(.*?)\"/i",
-			"<a href=\"#l_\\1\"",
-			$translation
+		$translation = HtmlHelper::modifyElements(
+			$translation,
+			static function ( SerializerNode $n ): bool {
+				return $n->name === 'a' && isset( $n->attrs['href'] ) && str_starts_with( $n->attrs['href'], '#' );
+			},
+			static function ( SerializerNode $n ): SerializerNode {
+				$n->attrs['href'] = '#l_' . substr( $n->attrs['href'], 1 );
+				return $n;
+			}
 		);
-		$translation = preg_replace(
-			"/<li id=\"(.*?)\"/i",
-			"<li id=\"l_\\1\"",
-			$translation
+		$translation = HtmlHelper::modifyElements(
+			$translation,
+			static function ( SerializerNode $n ): bool {
+				return $n->name === 'li' && isset( $n->attrs['id'] );
+			},
+			static function ( SerializerNode $n ): SerializerNode {
+				$n->attrs['id'] = 'l_' . $n->attrs['id'];
+				return $n;
+			}
 		);
 
-		$text = preg_replace(
-			"/<a href=\"#(.*?)\"/i",
-			"<a href=\"#r_\\1\"",
-			$text
+		$text = HtmlHelper::modifyElements(
+			$text,
+			static function ( SerializerNode $n ): bool {
+				return $n->name === 'a' && isset( $n->attrs['href'] ) && str_starts_with( $n->attrs['href'], '#' );
+			},
+			static function ( SerializerNode $n ): SerializerNode {
+				$n->attrs['href'] = '#r_' . substr( $n->attrs['href'], 1 );
+				return $n;
+			}
 		);
-		$text = preg_replace(
-			"/<li id=\"(.*?)\"/i",
-			"<li id=\"r_\\1\"",
-			$text
+		$text = HtmlHelper::modifyElements(
+			$text,
+			static function ( SerializerNode $n ): bool {
+				return $n->name === 'li' && isset( $n->attrs['id'] );
+			},
+			static function ( SerializerNode $n ): SerializerNode {
+				$n->attrs['id'] = 'r_' . $n->attrs['id'];
+				return $n;
+			}
 		);
 
 		// add ?match= to local links of the local wiki
-		$text = preg_replace(
-			"/<a href=\"\/([^\"\?]*)\"/i",
-			"<a href=\"/\\1?match={$matchLangCode}\"",
-			$text
+		$text = HtmlHelper::modifyElements(
+			$text,
+			static function ( SerializerNode $n ): bool {
+				return $n->name === 'a' && isset( $n->attrs['href'] )
+					&& str_starts_with( $n->attrs['href'], '/' )
+					&& !str_contains( $n->attrs['href'], '?' );
+			},
+			static function ( SerializerNode $n ) use ( $matchLangCode ): SerializerNode {
+				$n->attrs['href'] = wfAppendQuery( $n->attrs['href'], [ 'match' => $matchLangCode ] );
+				return $n;
+			}
 		);
 
 		return [ $text, $translation ];
-- 
2.28.0.windows.1