Add a CLI command that creates an empty LDAP config

This is needed to configure the user_ldap app without using the
wizard (e.g. using tools like Puppet).

apps/user_ldap/appinfo/register_command.php

@@ -9,3 +9,4 @@
 $application->add(new OCA\user_ldap\Command\ShowConfig());
 $application->add(new OCA\user_ldap\Command\SetConfig());
 $application->add(new OCA\user_ldap\Command\TestConfig());
+$application->add(new OCA\user_ldap\Command\CreateEmptyConfig());

apps/user_ldap/command/createemptyconfig.php

@@ -0,0 +1,51 @@
+<?php
+/**
+ * Copyright (c) 2014 Martin Konrad <info@martin-konrad.net>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OCA\user_ldap\Command;
+
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+use \OCA\user_ldap\lib\Helper;
+use \OCA\user_ldap\lib\Configuration;
+
+class CreateEmptyConfig extends Command {
+
+	protected function configure() {
+		$this
+			->setName('ldap:create-empty-config')
+			->setDescription('creates an empty LDAP configuration')
+		;
+	}
+
+
+	protected function execute(InputInterface $input, OutputInterface $output) {
+		$configPrefix = $this->getNewConfigurationPrefix();
+		$output->writeln("Created new configuration with configID '{$configPrefix}'");
+
+		$configHolder = new Configuration($configPrefix);
+		$configHolder->saveConfiguration();
+	}
+
+	protected function getNewConfigurationPrefix() {
+		$serverConnections = Helper::getServerConfigurationPrefixes();
+
+		// first connection uses no prefix
+		if(sizeof($serverConnections) == 0) {
+			return '';
+		}
+
+		sort($serverConnections);
+		$lastKey = array_pop($serverConnections);
+		$lastNumber = intval(str_replace('s', '', $lastKey));
+		$nextPrefix = 's' . str_pad($lastNumber + 1, 2, '0', STR_PAD_LEFT);
+		return $nextPrefix;
+	}
+}