Maintenance mode (#326)

* Replace direct access to sites with getSites

* Add a new maintenance listener, which can enable/disable maintenance mode for specific commands

* Rename the getMaintenance to isMaintenance

src/Application.php

@@ -20,6 +20,7 @@
 use Drupal\Console\Core\EventSubscriber\ShowGeneratedFilesListener;
 use Drupal\Console\Core\EventSubscriber\ShowGenerateInlineListener;
 use Drupal\Console\Core\EventSubscriber\CallCommandListener;
+use Drupal\Console\Core\EventSubscriber\MaintenanceModeListener;
 use Drupal\Console\Core\Utils\ConfigurationManager;
 use Drupal\Console\Core\Style\DrupalStyle;
 use Drupal\Console\Core\Utils\ChainDiscovery;
@@ -310,6 +311,13 @@ private function registerEvents()
                 )
             );
 
+            $dispatcher->addSubscriber(
+                new MaintenanceModeListener(
+                    $this->container->get('console.translator_manager'),
+                    $this->container->get('state')
+                )
+            );
+
             $this->setDispatcher($dispatcher);
             $this->eventRegistered = true;
         }

src/Command/Command.php

@@ -33,6 +33,11 @@ abstract class Command extends BaseCommand
      */
     private $io;
 
+    /**
+     * @var bool
+     */
+    private $maintenance = false;
+
     /**
      * {@inheritdoc}
      */
@@ -49,6 +54,34 @@ public function getIo()
         return $this->io;
     }
 
+    /**
+     * Check maintenance mode.
+     *
+     * @return bool
+     */
+    public function isMaintenance()
+    {
+        return $this->maintenance;
+    }
+
+    /**
+     * Enable maintenance mode.
+     *
+     * @return $this
+     *   Command.
+     */
+    public function enableMaintenance()
+    {
+        $this->maintenance = true;
+        return $this;
+    }
+
+    /**
+     * Create Exception
+     *
+     * @return void
+     * 
+     */ 
     public function createException($message) {
         $this->getIo()->error($message);
         exit(1);

src/EventSubscriber/MaintenanceModeListener.php

@@ -0,0 +1,116 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Console\Core\EventSubscriber\MaintenanceModeListener.
+ */
+
+namespace Drupal\Console\Core\EventSubscriber;
+
+use Drupal\Core\State\StateInterface;
+use Drupal\Console\Core\Style\DrupalStyle;
+use Drupal\Console\Core\Utils\TranslatorManagerInterface;
+use Symfony\Component\Console\ConsoleEvents;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Event\ConsoleEvent;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Class MaintenanceModeListener
+ *
+ * @package Drupal\Console\Core\EventSubscriber
+ */
+class MaintenanceModeListener implements EventSubscriberInterface
+{
+    /**
+     * @var TranslatorManagerInterface
+     */
+    protected $translator;
+
+    /**
+     * @var StateInterface
+     */
+    protected $state;
+
+    /**
+     * MaintenanceModeListener constructor.
+     *
+     * @param TranslatorManagerInterface $translator
+     * @param StateInterface $state
+     */
+    public function __construct(
+        TranslatorManagerInterface $translator,
+        StateInterface $state
+    ) {
+        $this->translator = $translator;
+        $this->state = $state;
+    }
+
+    /**
+     * Enable maintenance mode.
+     *
+     * @param ConsoleEvent $event
+     */
+    public function enableMaintenanceMode(ConsoleEvent $event)
+    {
+        $this->switchMaintenanceMode($event, 'on');
+    }
+
+    /**
+     * Disable maintenance mode.
+     *
+     * @param ConsoleEvent $event
+     */
+    public function disableMaintenanceMode(ConsoleEvent $event)
+    {
+        $this->switchMaintenanceMode($event, 'off');
+    }
+
+    /**
+     * Switch maintenance mode.
+     *
+     * @param ConsoleEvent $event
+     * @param string $mode
+     */
+    public function switchMaintenanceMode(ConsoleEvent $event, $mode)
+    {
+        /* @var Command $command */
+        $command = $event->getCommand();
+
+        if ($command->isMaintenance()) {
+
+            /* @var DrupalStyle $io */
+            $io = new DrupalStyle($event->getInput(), $event->getOutput());
+            $stateName = 'system.maintenance_mode';
+            $modeMessage = null;
+
+            if ($mode == 'on') {
+                $this->state->set($stateName, true);
+                $modeMessage = $this->translator->trans('commands.site.maintenance.messages.maintenance-on');
+            }
+
+            if ($mode == 'off') {
+                $this->state->set($stateName, false);
+                $modeMessage = $this->translator->trans('commands.site.maintenance.messages.maintenance-off');
+            }
+
+            if ($modeMessage) {
+                $io->newLine();
+                $io->info($modeMessage, true);
+                $io->newLine();
+            }
+        }
+    }
+
+
+    /**
+     * @{@inheritdoc}
+     */
+    public static function getSubscribedEvents()
+    {
+        return [
+            ConsoleEvents::COMMAND => 'enableMaintenanceMode',
+            ConsoleEvents::TERMINATE => 'disableMaintenanceMode',
+        ];
+    }
+}