add subscription cleanup feature

Author: DavidBadura

src/Attribute/Cleanup.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Attribute;
+
+use Attribute;
+
+#[Attribute(Attribute::TARGET_METHOD)]
+final class Cleanup
+{
+}

src/Metadata/Subscriber/AttributeSubscriberMetadataFactory.php

@@ -4,6 +4,7 @@
 
 namespace Patchlevel\EventSourcing\Metadata\Subscriber;
 
+use Patchlevel\EventSourcing\Attribute\Cleanup;
 use Patchlevel\EventSourcing\Attribute\OnFailed;
 use Patchlevel\EventSourcing\Attribute\RetryStrategy;
 use Patchlevel\EventSourcing\Attribute\Setup;
@@ -45,6 +46,7 @@ public function metadata(string $subscriber): SubscriberMetadata
         $subscribeMethods = [];
         $setupMethod = null;
         $teardownMethod = null;
+        $cleanupMethod = null;
         $failedMethod = null;
 
         foreach ($methods as $method) {
@@ -90,6 +92,18 @@ public function metadata(string $subscriber): SubscriberMetadata
                 $setupMethod = $method->getName();
             }
 
+            if ($method->getAttributes(Cleanup::class)) {
+                if ($cleanupMethod !== null) {
+                    throw new DuplicateCleanupMethod(
+                        $subscriber,
+                        $cleanupMethod,
+                        $method->getName(),
+                    );
+                }
+
+                $cleanupMethod = $method->getName();
+            }
+
             if (!$method->getAttributes(Teardown::class)) {
                 continue;
             }
@@ -118,6 +132,7 @@ public function metadata(string $subscriber): SubscriberMetadata
             $teardownMethod,
             $failedMethod,
             $this->retryStrategy($reflector),
+            $cleanupMethod,
         );
 
         $this->subscriberMetadata[$subscriber] = $metadata;

src/Metadata/Subscriber/DuplicateCleanupMethod.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Metadata\Subscriber;
+
+use Patchlevel\EventSourcing\Metadata\MetadataException;
+
+use function sprintf;
+
+final class DuplicateCleanupMethod extends MetadataException
+{
+    /** @param class-string $subscriber */
+    public function __construct(string $subscriber, string $fistMethod, string $secondMethod)
+    {
+        parent::__construct(
+            sprintf(
+                'Two methods "%s" and "%s" on the subscriber "%s" have been marked as "cleanup" methods. Only one method can be defined like this.',
+                $fistMethod,
+                $secondMethod,
+                $subscriber,
+            ),
+        );
+    }
+}

src/Metadata/Subscriber/SubscriberMetadata.php

@@ -19,6 +19,7 @@ public function __construct(
         public readonly string|null $teardownMethod = null,
         public readonly string|null $failedMethod = null,
         public readonly string|null $retryStrategy = null,
+        public readonly string|null $cleanupMethod = null,
     ) {
     }
 }

src/Subscription/Cleanup/Cleaner.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Subscription\Cleanup;
+
+use Patchlevel\EventSourcing\Subscription\Subscription;
+
+interface Cleaner
+{
+    public function cleanup(Subscription $subscription): void;
+}

src/Subscription/Cleanup/CleanupHandler.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Subscription\Cleanup;
+
+interface CleanupHandler
+{
+    public function __invoke(object $task): void;
+}

src/Subscription/Cleanup/Dbal/DbalCleanupHandler.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Subscription\Cleanup\Dbal;
+
+use Doctrine\DBAL\Connection;
+use Patchlevel\EventSourcing\Subscription\Cleanup\CleanupHandler;
+
+final class DbalCleanupHandler implements CleanupHandler
+{
+    public function __construct(
+        private readonly Connection $connection,
+    ) {
+    }
+
+    public function __invoke(object $task): void
+    {
+        if ($task instanceof RemoveDbalTableTask) {
+            $this->connection->createSchemaManager()->dropTable($task->table);
+        }
+
+        if ($task instanceof RemoveDbalIndexTask) {
+            $this->connection->createSchemaManager()->dropIndex($task->index, $task->table);
+        }
+    }
+}

src/Subscription/Cleanup/Dbal/RemoveDbalIndexTask.php

@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Subscription\Cleanup\Dbal;
+
+final class RemoveDbalIndexTask
+{
+    public function __construct(
+        public readonly string $index,
+        public readonly string $table
+    ) {
+    }
+}

src/Subscription/Cleanup/Dbal/RemoveDbalTableTask.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Subscription\Cleanup\Dbal;
+
+final class RemoveDbalTableTask
+{
+    public function __construct(public readonly string $table)
+    {
+    }
+}

src/Subscription/Cleanup/DefaultCleaner.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Subscription\Cleanup;
+
+use Patchlevel\EventSourcing\Subscription\Subscription;
+use Psr\Log\LoggerInterface;
+
+class DefaultCleaner implements Cleaner
+{
+    /** @param iterable<CleanupHandler> $handlers */
+    public function __construct(
+        private readonly iterable $handlers,
+        private readonly LoggerInterface|null $logger = null,
+    ) {
+    }
+
+    public function cleanup(Subscription $subscription): void
+    {
+        $tasks = $subscription->cleanupTasks();
+
+        if (!$tasks) {
+            $this->logger?->debug('no cleanup tasks found');
+
+            return;
+        }
+
+        foreach ($tasks as $task) {
+            foreach ($this->handlers as $handler) {
+                $handler($task);
+            }
+        }
+    }
+}