From 0351c7b04ae7ade87ee488b45ec5359706c20694 Mon Sep 17 00:00:00 2001
From: theUniC <theunic@gmail.com>
Date: Sun, 4 Sep 2022 17:41:12 +0200
Subject: [PATCH] 06. Introduction of CommandBus

---
 config/packages/messenger.yaml                |  6 +++++
 .../Controller/PostFollowersController.php    |  6 ++---
 src/Cheeper/Application/CommandBus.php        | 12 ++++++++++
 .../Follow/FollowCommandHandler.php           |  2 ++
 .../SymfonyMessengerCommandBus.php            | 22 +++++++++++++++++++
 5 files changed, 45 insertions(+), 3 deletions(-)
 create mode 100644 src/Cheeper/Application/CommandBus.php
 create mode 100644 src/Cheeper/Infrastructure/Application/SymfonyMessengerCommandBus.php

diff --git a/config/packages/messenger.yaml b/config/packages/messenger.yaml
index fe1e6a8..a45c1c5 100644
--- a/config/packages/messenger.yaml
+++ b/config/packages/messenger.yaml
@@ -6,6 +6,12 @@ framework:
         buses:
             default:
                 default_middleware: allow_no_handlers
+            command_bus:
+                middleware:
+                    - validation
+                    - doctrine_ping_connection
+                    - doctrine_close_connection
+                    - doctrine_transaction
 
         transports:
             # https://symfony.com/doc/current/messenger.html#transport-configuration
diff --git a/src/App/Controller/PostFollowersController.php b/src/App/Controller/PostFollowersController.php
index 1b5c344..c4d4923 100644
--- a/src/App/Controller/PostFollowersController.php
+++ b/src/App/Controller/PostFollowersController.php
@@ -4,8 +4,8 @@ declare(strict_types=1);
 
 namespace App\Controller;
 
+use Cheeper\Application\CommandBus;
 use Cheeper\Application\Follow\FollowCommand;
-use Cheeper\Application\Follow\FollowCommandHandler;
 use Cheeper\DomainModel\Author\AuthorDoesNotExist;
 use OpenApi\Attributes as OA;
 use Psl\Json;
@@ -20,8 +20,8 @@ use Symfony\Component\Validator\Validator\ValidatorInterface;
 final class PostFollowersController extends AbstractController
 {
     public function __construct(
-        private readonly FollowCommandHandler $followCommandHandler,
         private readonly ValidatorInterface $validator,
+        private readonly CommandBus $commandBus,
     ) {
     }
 
@@ -95,7 +95,7 @@ final class PostFollowersController extends AbstractController
         }
 
         try {
-            ($this->followCommandHandler)(
+            $this->commandBus->handle(
                 new FollowCommand(
                     $data['from_author_id'],
                     $data['to_author_id']
diff --git a/src/Cheeper/Application/CommandBus.php b/src/Cheeper/Application/CommandBus.php
new file mode 100644
index 0000000..e38b00f
--- /dev/null
+++ b/src/Cheeper/Application/CommandBus.php
@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Cheeper\Application;
+
+/** @template T of Command */
+interface CommandBus
+{
+    /** @psalm-param T $command */
+    public function handle(Command $command): void;
+}
\ No newline at end of file
diff --git a/src/Cheeper/Application/Follow/FollowCommandHandler.php b/src/Cheeper/Application/Follow/FollowCommandHandler.php
index 83443a4..37956df 100644
--- a/src/Cheeper/Application/Follow/FollowCommandHandler.php
+++ b/src/Cheeper/Application/Follow/FollowCommandHandler.php
@@ -10,7 +10,9 @@ use Cheeper\DomainModel\Author\AuthorDoesNotExist;
 use Cheeper\DomainModel\Author\AuthorId;
 use Cheeper\DomainModel\Author\AuthorRepository;
 use Cheeper\DomainModel\Follow\FollowRepository;
+use Symfony\Component\Messenger\Attribute\AsMessageHandler;
 
+#[AsMessageHandler]
 final class FollowCommandHandler
 {
     public function __construct(
diff --git a/src/Cheeper/Infrastructure/Application/SymfonyMessengerCommandBus.php b/src/Cheeper/Infrastructure/Application/SymfonyMessengerCommandBus.php
new file mode 100644
index 0000000..c4570c6
--- /dev/null
+++ b/src/Cheeper/Infrastructure/Application/SymfonyMessengerCommandBus.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Cheeper\Infrastructure\Application;
+
+use Cheeper\Application\Command;
+use Cheeper\Application\CommandBus;
+use Symfony\Component\Messenger\MessageBusInterface;
+
+final class SymfonyMessengerCommandBus implements CommandBus
+{
+    public function __construct(
+        private readonly MessageBusInterface $commandBus
+    ) {
+    }
+
+    public function handle(Command $command): void
+    {
+        $this->commandBus->dispatch($command);
+    }
+}
\ No newline at end of file