LDAP: enable support for multiple LDAP/AD servers

apps/user_ldap/appinfo/app.php

@@ -23,11 +23,27 @@
 
 OCP\App::registerAdmin('user_ldap', 'settings');
 
-$connector = new OCA\user_ldap\lib\Connection('', 'user_ldap');
-$userBackend  = new OCA\user_ldap\USER_LDAP();
-$userBackend->setConnector($connector);
-$groupBackend = new OCA\user_ldap\GROUP_LDAP();
-$groupBackend->setConnector($connector);
+$query = \OCP\DB::prepare('
+	SELECT DISTINCT `configkey`
+	FROM `*PREFIX*appconfig`
+	WHERE `configkey` LIKE ?
+');
+$serverConnections = $query->execute(array('%ldap_login_filter'))->fetchAll();
+if(count($serverConnections) == 1) {
+	$prefix = substr($serverConnections[0]['configkey'], 0, strlen($serverConnections[0]['configkey'])- strlen('ldap_login_filter'));
+	$connector = new OCA\user_ldap\lib\Connection($prefix);
+	$userBackend  = new OCA\user_ldap\USER_LDAP();
+	$userBackend->setConnector($connector);
+	$groupBackend = new OCA\user_ldap\GROUP_LDAP();
+	$groupBackend->setConnector($connector);
+} else {
+	$prefixes = array();
+	foreach($serverConnections as $serverConnection) {
+		$prefixes[] = substr($serverConnection['configkey'], 0, strlen($serverConnection['configkey'])- strlen('ldap_login_filter'));
+	}
+	$userBackend  = new OCA\user_ldap\User_Proxy($prefixes);
+	$groupBackend  = new OCA\user_ldap\Group_Proxy($prefixes);
+}
 
 // register user backend
 OC_User::useBackend($userBackend);