From ef8a95b59360773ec0c1d48c8978d73060d75c8f Mon Sep 17 00:00:00 2001
From: Albert Haff <ahn@haffdata.com>
Date: Tue, 19 Jan 2021 18:31:51 +0100
Subject: [PATCH] Add base subscription

---
 README.md                                     | 34 +++++++++++++++++--
 src/Exceptions/NoSubscriptionException.php    |  5 +++
 .../Directives/SubscribableDirective.php      | 13 ++++++-
 .../FairwayModelEventSubscription.php         | 24 +++++++++++++
 src/Subscriptions/ModelEventSubscription.php  | 20 -----------
 src/lighthouse-fairway.php                    |  5 +++
 6 files changed, 77 insertions(+), 24 deletions(-)
 create mode 100644 src/Exceptions/NoSubscriptionException.php
 create mode 100644 src/Subscriptions/FairwayModelEventSubscription.php
 delete mode 100644 src/Subscriptions/ModelEventSubscription.php

diff --git a/README.md b/README.md
index e9b2113..b59fa59 100644
--- a/README.md
+++ b/README.md
@@ -9,14 +9,42 @@ This extension brings [Fairway](https://github.com/buoy-graphql/fairway-spec)-co
 composer require buoy/lighthouse-fairway
 ```
 
-## Configuration
-
-Lighthouse Fairway has a configuration file that can be published:
+Then publish the configuration.
 
 ```shell
 php artisan vendor:publish --tag=lighthouse-fairway-config  
 ```
 
+Then create the class that will handle authorization and filtering for your subscriptions:
+
+```php
+<?php
+
+namespace App\GraphQL\Subscriptions;
+
+use Buoy\LighthouseFairway\Subscriptions\FairwayModelEventSubscription;
+use Illuminate\Http\Request;
+use Nuwave\Lighthouse\Subscriptions\Subscriber;
+
+class FairwayModelSubscription extends FairwayModelEventSubscription
+{
+    public function authorize(Subscriber $subscriber, Request $request): bool
+    {
+        // Authorize the user
+        return true;
+    }
+
+    public function filterSubscription(Subscriber $subscriber, $root): bool
+    {
+        // Add filtering here. Filtering based on event type is handled for you.
+        return true;
+    }
+}
+```
+
+Lastly, enter the namespace for your subscription-class in the `lighthouse-fairway.php` config-file
+
+
 ## Usage
 
 This library adds some shortcuts to making models subscribable.
diff --git a/src/Exceptions/NoSubscriptionException.php b/src/Exceptions/NoSubscriptionException.php
new file mode 100644
index 0000000..0a323aa
--- /dev/null
+++ b/src/Exceptions/NoSubscriptionException.php
@@ -0,0 +1,5 @@
+<?php
+
+namespace Buoy\LighthouseFairway\Exceptions;
+
+class NoSubscriptionException extends \Exception { }
diff --git a/src/Schema/Directives/SubscribableDirective.php b/src/Schema/Directives/SubscribableDirective.php
index f354ae9..39e1d52 100644
--- a/src/Schema/Directives/SubscribableDirective.php
+++ b/src/Schema/Directives/SubscribableDirective.php
@@ -2,6 +2,7 @@
 
 namespace Buoy\LighthouseFairway\Schema\Directives;
 
+use Buoy\LighthouseFairway\Exceptions\NoSubscriptionException;
 use GraphQL\Language\AST\TypeDefinitionNode;
 use GraphQL\Language\Parser;
 use Illuminate\Support\Str;
@@ -21,6 +22,9 @@ public static function definition(): string
 SDL;
     }
 
+    /**
+     * @throws NoSubscriptionException
+     */
     public function manipulateTypeDefinition(DocumentAST &$documentAST, TypeDefinitionNode &$typeDefinition): void
     {
         $model = $typeDefinition->name->value;
@@ -35,11 +39,18 @@ public function manipulateTypeDefinition(DocumentAST &$documentAST, TypeDefiniti
         ");
 
         $subscription = Str::camel(class_basename($model)) . 'Modified';
+        $subscriptionClass = '\\'.config('lighthouse-fairway.subscription_class');
+
+        if (!class_exists($subscriptionClass)) {
+            throw new NoSubscriptionException('"subscription_class" in the lighthouse-fairway config must be a valid namespace.');
+        }
+
+        $subscriptionClass = str_replace('\\', '\\\\', $subscriptionClass);
 
         $documentAST->types["Subscription"] = Parser::objectTypeDefinition(/** @lang GraphQL */"
             type Subscription {
                 {$subscription}(events: [EventType!], id: ID): {$model}Event
-                @subscription(class: \"\\\\Buoy\\\\LighthouseFairway\\\\Subscriptions\\\\ModelEventSubscription\")
+                @subscription(class: \"{$subscriptionClass}\")
             }
         ");
     }
diff --git a/src/Subscriptions/FairwayModelEventSubscription.php b/src/Subscriptions/FairwayModelEventSubscription.php
new file mode 100644
index 0000000..1ba64c0
--- /dev/null
+++ b/src/Subscriptions/FairwayModelEventSubscription.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace Buoy\LighthouseFairway\Subscriptions;
+
+use Nuwave\Lighthouse\Schema\Types\GraphQLSubscription;
+use Nuwave\Lighthouse\Subscriptions\Subscriber;
+
+abstract class FairwayModelEventSubscription extends GraphQLSubscription
+{
+    abstract public function filterSubscription(Subscriber $subscriber, $root): bool;
+
+    public function filter(Subscriber $subscriber, $root): bool
+    {
+        // Filter based on event type
+        if (optional($subscriber->args)['events']) {
+            if (!in_array($root['event'], $subscriber->args['events'])) {
+                return false;
+            }
+        }
+
+        // Custom filtering
+        return $this->filterSubscription($subscriber, $root);
+    }
+}
diff --git a/src/Subscriptions/ModelEventSubscription.php b/src/Subscriptions/ModelEventSubscription.php
deleted file mode 100644
index bcd3b52..0000000
--- a/src/Subscriptions/ModelEventSubscription.php
+++ /dev/null
@@ -1,20 +0,0 @@
-<?php
-
-namespace Buoy\LighthouseFairway\Subscriptions;
-
-use Illuminate\Http\Request;
-use Nuwave\Lighthouse\Schema\Types\GraphQLSubscription;
-use Nuwave\Lighthouse\Subscriptions\Subscriber;
-
-class ModelEventSubscription extends GraphQLSubscription
-{
-    public function authorize(Subscriber $subscriber, Request $request)
-    {
-        return true;
-    }
-
-    public function filter(Subscriber $subscriber, $root)
-    {
-        return true; // TODO
-    }
-}
\ No newline at end of file
diff --git a/src/lighthouse-fairway.php b/src/lighthouse-fairway.php
index 9ef5253..2b8905e 100644
--- a/src/lighthouse-fairway.php
+++ b/src/lighthouse-fairway.php
@@ -10,4 +10,9 @@
      * Automatically add Fairway client directives to the schema?
      */
     'add_client_directives' => true,
+
+    /**
+     * The class that will be invoked for subscriptions.
+     */
+    'subscription_class' => null,
 ];