Add categories module

Change-Id: I0d2f768605e66a91a51593d7a4748a49cf161cad

StandardWikitext.php

@@ -57,6 +57,7 @@ public static function fixWikitext( $wikitext ) {
 		$wikitext = self::fixReferences( $wikitext );
 		$wikitext = self::fixLists( $wikitext );
 		$wikitext = self::fixSections( $wikitext );
+		$wikitext = self::fixCategories( $wikitext );
 		$wikitext = self::fixSpacing( $wikitext );
 		return $wikitext;
 	}
@@ -357,6 +358,26 @@ public static function fixSections( $wikitext ) {
 		return $wikitext;
 	}
 
+	/**
+	 * Move categories to the bottom
+	 * @todo Only works in English
+	 */
+    public static function fixCategories( $wikitext ) {
+		$count = preg_match_all( "/\n*\[\[ ?[Cc]ategory ?: ?([^]]+) ?\]\]/", $wikitext, $matches );
+		if ( $count ) {
+			foreach ( $matches[0] as $match ) {
+				$wikitext = str_replace( $match, '', $wikitext );
+			}
+			$categories = $matches[1];
+			$categories = array_unique( $categories );
+			$wikitext .= "\n";
+			foreach ( $categories as $category ) {
+				$wikitext .= "\n[[Category:$category]]";
+			}
+		}
+		return $wikitext;
+    }
+
 	public static function fixSpacing( $wikitext ) {
 		// Give block templates some room
 		$templates = self::getElements( "\n{{", "}}\n", $wikitext );

extension.json

@@ -1,6 +1,6 @@
 {
 	"name": "StandardWikitext",
-	"version": "2.0",
+	"version": "2.1",
 	"author": "[https://www.mediawiki.org/wiki/User:Sophivorus Sophivorus]",
 	"url": "https://www.mediawiki.org/wiki/Extension:StandardWikitext",
 	"descriptionmsg": "standardwikitext-desc",