Added recording of users checking into buildings

container.php

@@ -169,6 +169,17 @@ public function onRoute(ActionEvent $actionEvent) : void
                 $buildings->store(Building::new($command->name()));
             };
         },
+        Command\CheckIn::class => function (ContainerInterface $container) : callable {
+            $buildings = $container->get(BuildingRepositoryInterface::class);
+
+            return function (Command\CheckIn $command) use ($buildings) : void {
+                $building = $buildings->get($command->building());
+
+                $building->checkInUser($command->username());
+
+                $buildings->store($building);
+            };
+        },
         BuildingRepositoryInterface::class => function (ContainerInterface $container) : BuildingRepositoryInterface {
             return new BuildingRepository(
                 new AggregateRepository(

public/index.php

@@ -86,8 +86,16 @@
         return $response;
     });
 
-    $app->post('/checkin/{buildingId}', function (Request $request, Response $response) use ($sm) : Response {
-        throw new \BadFunctionCallException('To be implemented: I should dispatch a command and redirect back to the previous page');
+    $app->post('/checkin/{buildingId}', function (Request $request, Response $response) use ($sm, $getBodyParameter) : Response {
+        $sm->get(CommandBus::class)
+            ->dispatch(Command\CheckIn::fromBuildingAndUsername(
+                Uuid::fromString($request->getAttribute('buildingId')),
+                $getBodyParameter($request, 'username')
+            ));
+
+        return $response
+            ->withStatus(302, 'Found')
+            ->withAddedHeader('Location', '/building/' . $request->getAttribute('buildingId'));
     });
 
     $app->post('/checkout/{buildingId}', function (Request $request, Response $response) use ($sm) : Response {

src/Domain/Aggregate/Building.php

@@ -5,6 +5,7 @@
 namespace Building\Domain\Aggregate;
 
 use Building\Domain\DomainEvent\NewBuildingWasRegistered;
+use Building\Domain\DomainEvent\UserCheckedIn;
 use Prooph\EventSourcing\AggregateRoot;
 use Rhumsaa\Uuid\Uuid;
 use Webmozart\Assert\Assert;
@@ -26,7 +27,11 @@ public static function new(string $name) : self
 
     public function checkInUser(string $username) : void
     {
-        throw new \BadFunctionCallException('To be implemented: I should record a new event on the building');
+        $id = $this->uuid;
+
+        Assert::notNull($id);
+
+        $this->recordThat(UserCheckedIn::toBuilding($id, $username));
     }
 
     public function checkOutUser(string $username) : void
@@ -40,6 +45,11 @@ protected function whenNewBuildingWasRegistered(NewBuildingWasRegistered $event)
         $this->name = $event->name();
     }
 
+    protected function whenUserCheckedIn(UserCheckedIn $event) : void
+    {
+        // Empty (on purpose)
+    }
+
     /** {@inheritDoc} */
     protected function aggregateId() : string
     {

src/Domain/Command/CheckIn.php

@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Building\Domain\Command;
+
+use Prooph\Common\Messaging\Command;
+use Rhumsaa\Uuid\Uuid;
+
+final class CheckIn extends Command
+{
+    private Uuid $building;
+    private string $username;
+
+    private function __construct(Uuid $building, string $username)
+    {
+        $this->init();
+
+        $this->building = $building;
+        $this->username = $username;
+    }
+
+    public static function fromBuildingAndUsername(Uuid $building, string $username) : self
+    {
+        return new self($building, $username);
+    }
+
+    public function building() : Uuid
+    {
+        return $this->building;
+    }
+
+    public function username() : string
+    {
+        return $this->username;
+    }
+
+    /** {@inheritDoc} */
+    public function payload() : array
+    {
+        return [
+            'building' => $this->building->toString(),
+            'username' => $this->username,
+        ];
+    }
+
+    /** {@inheritDoc} */
+    protected function setPayload(array $payload)
+    {
+        $this->building = Uuid::fromString($payload['building']);
+        $this->username = $payload['username'];
+    }
+}

src/Domain/DomainEvent/UserCheckedIn.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Building\Domain\DomainEvent;
+
+use Prooph\EventSourcing\AggregateChanged;
+use Rhumsaa\Uuid\Uuid;
+
+final class UserCheckedIn extends AggregateChanged
+{
+    public static function toBuilding(Uuid $building, string $username) : self
+    {
+        return self::occur($building->toString(), ['username' => $username]);
+    }
+
+    public function username() : string
+    {
+        return $this->payload['username'];
+    }
+}