Introduce InterwikiLookupAdapter on top of SiteLookup

This adapter assumes the db name (Interwiki wiki id) equals global ids.

Bug: T135146
Change-Id: I387dc2ff3f5564fcedde835dec66781d8e9424fd

1 files changed, 175 insertions, 0 deletions

diff --git a/includes/interwiki/InterwikiLookupAdapter.php b/includes/interwiki/InterwikiLookupAdapter.php
new file mode 100644
index 000000000000..a17bdd9b2e00
--- /dev/null
+++ b/includes/interwiki/InterwikiLookupAdapter.php
@@ -0,0 +1,175 @@
+<?php
+namespace MediaWiki\Interwiki;
+
+/**
+ * InterwikiLookupAdapter on top of SiteLookup
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ *
+ * @since 1.28
+ * @ingroup InterwikiLookup
+ *
+ * @license GNU GPL v2+
+ */
+
+use Interwiki;
+use Site;
+use SiteLookup;
+use MediawikiSite;
+
+class InterwikiLookupAdapter implements InterwikiLookup {
+
+	/**
+	 * @var SiteLookup
+	 */
+	private $siteLookup;
+
+	/**
+	 * @var Interwiki[]|null associative array mapping interwiki prefixes to Interwiki objects
+	 */
+	private $interwikiMap;
+
+	function __construct(
+		SiteLookup $siteLookup,
+		array $interwikiMap = null
+	) {
+		$this->siteLookup = $siteLookup;
+		$this->interwikiMap = $interwikiMap;
+	}
+
+	/**
+	 * See InterwikiLookup::isValidInterwiki
+	 * It loads the whole interwiki map.
+	 *
+	 * @param string $prefix Interwiki prefix to use
+	 * @return bool Whether it exists
+	 */
+	public function isValidInterwiki( $prefix ) {
+
+		return array_key_exists( $prefix, $this->getInterwikiMap() );
+	}
+
+	/**
+	 * See InterwikiLookup::fetch
+	 * It loads the whole interwiki map.
+	 *
+	 * @param string $prefix Interwiki prefix to use
+	 * @return Interwiki|null|bool
+	 */
+	public function fetch( $prefix ) {
+		if ( $prefix == '' ) {
+			return null;
+		}
+
+		if ( !$this->isValidInterwiki( $prefix ) ) {
+			return false;
+		}
+
+		return $this->interwikiMap[$prefix];
+	}
+
+	/**
+	 * See InterwikiLookup::getAllPrefixes
+	 *
+	 * @param string|null $local If set, limits output to local/non-local interwikis
+	 * @return string[] List of prefixes
+	 */
+	public function getAllPrefixes( $local = null ) {
+		if ( $local === null ) {
+			return array_keys( $this->getInterwikiMap() );
+		}
+		$res = [];
+		foreach ( $this->getInterwikiMap() as $interwikiId => $interwiki ) {
+			if ( $interwiki->isLocal() === $local ) {
+				$res[] = $interwikiId;
+			}
+		}
+		return $res;
+	}
+
+	/**
+	 * See InterwikiLookup::invalidateCache
+	 *
+	 * @param string $prefix
+	 */
+	public function invalidateCache( $prefix ) {
+		if ( !isset( $this->interwikiMap[$prefix] ) ) {
+			return;
+		}
+		$globalId = $this->interwikiMap[$prefix]->getWikiID();
+		unset( $this->interwikiMap[$prefix] );
+
+		// Reload the interwiki
+		$site = $this->siteLookup->getSites()->getSite( $globalId );
+		$interwikis = $this->getSiteInterwikis( $site );
+		$this->interwikiMap = array_merge( $this->interwikiMap, [ $interwikis[$prefix] ] );
+	}
+
+	/**
+	 * Load interwiki map to use as cache
+	 */
+	private function loadInterwikiMap() {
+		$interwikiMap = [];
+		$siteList = $this->siteLookup->getSites();
+		foreach ( $siteList as $site ) {
+			$interwikis = $this->getSiteInterwikis( $site );
+			$interwikiMap = array_merge( $interwikiMap, $interwikis );
+		}
+		$this->interwikiMap = $interwikiMap;
+	}
+
+	/**
+	 * Get interwikiMap attribute, load if needed.
+	 *
+	 * @return Interwiki[]
+	 */
+	private function getInterwikiMap() {
+		if ( $this->interwikiMap === null ) {
+			$this->loadInterwikiMap();
+		}
+		return $this->interwikiMap;
+	}
+
+	/**
+	 * Load interwikis for the given site
+	 *
+	 * @param Site $site
+	 * @return Interwiki[]
+	 */
+	private function getSiteInterwikis( Site $site ) {
+		$interwikis = [];
+		foreach ( $site->getInterwikiIds() as $interwiki ) {
+			$url = $site->getPageUrl();
+			if ( $site instanceof MediawikiSite ) {
+				$path = $site->getFileUrl( 'api.php' );
+			} else {
+				$path = '';
+			}
+			$local = $site->getSource() === 'local';
+			// TODO: How to adapt trans?
+			$interwikis[$interwiki] = new Interwiki(
+				$interwiki,
+				$url,
+				$path,
+				$site->getGlobalId(),
+				$local
+			);
+		}
+		return $interwikis;
+	}
+}