georgeboot · jdavidbakr · May 6, 2022 · May 13, 2022
diff --git a/js-src/Channel.ts b/js-src/Channel.ts
@@ -117,7 +117,9 @@ export class Channel extends BaseChannel implements PresenceChannel {
     }
 
     here(callback: Function): Channel {
-        // TODO: implement
+        this.on('subscription_succeeded', (data) => {
+            callback(data)
+        })
 
         return this
     }
@@ -126,7 +128,9 @@ export class Channel extends BaseChannel implements PresenceChannel {
      * Listen for someone joining the channel.
      */
     joining(callback: Function): Channel {
-        // TODO: implement
+        this.on('member_added', (data) => {
+            callback(data)
+        })
 
         return this
     }
@@ -135,7 +139,9 @@ export class Channel extends BaseChannel implements PresenceChannel {
      * Listen for someone leaving the channel.
      */
     leaving(callback: Function): Channel {
-        // TODO: implement
+        this.on('member_removed', (data) => {
+            callback(data)
+        })
 
         return this
     }

diff --git a/src/ConnectionRepository.php b/src/ConnectionRepository.php
@@ -5,6 +5,7 @@
 use Aws\ApiGatewayManagementApi\ApiGatewayManagementApiClient;
 use Aws\ApiGatewayManagementApi\Exception\ApiGatewayManagementApiException;
 use GuzzleHttp\Exception\ClientException;
+use Symfony\Component\HttpFoundation\Response;
 
 class ConnectionRepository
 {
@@ -28,8 +29,11 @@ public function sendMessage(string $connectionId, string $data): void
                 'Data' => $data,
             ]);
         } catch (ApiGatewayManagementApiException $e) {
-             // GoneException: The connection with the provided id no longer exists.
-             if ($e->getAwsErrorCode() === 'GoneException') {
+            // GoneException: The connection with the provided id no longer exists.
+            if (
+                $e->getStatusCode() === Response::HTTP_GONE ||
+                $e->getAwsErrorCode() === 'GoneException'
+            ) {
                 $this->subscriptionRepository->clearConnection($connectionId);
 
                 return;

diff --git a/src/Handler.php b/src/Handler.php
@@ -9,6 +9,7 @@
 use Bref\Event\Http\HttpResponse;
 use Illuminate\Support\Arr;
 use Illuminate\Support\Str;
+use Symfony\Component\HttpFoundation\Response;
 use Throwable;
 
 class Handler extends WebsocketHandler
@@ -42,6 +43,7 @@ public function handleWebsocket(WebsocketEvent $event, Context $context): HttpRe
 
     protected function handleDisconnect(WebsocketEvent $event, Context $context): void
     {
+        $this->sendPresenceDisconnectNotices($event);
         $this->subscriptionRepository->clearConnection($event->getConnectionId());
     }
 
@@ -115,12 +117,28 @@ protected function subscribe(WebsocketEvent $event, Context $context): void
             }
         }
 
-        $this->subscriptionRepository->subscribeToChannel($event->getConnectionId(), $channel);
+        if (Str::startsWith($channel, 'presence-')) {
+            $this->subscriptionRepository->subscribeToPresenceChannel(
+                $event->getConnectionId(),
+                $channelData,
+                $channel
+            );
+            $data = $this->subscriptionRepository->getUserListForPresenceChannel($channel)
+                ->transform(function ($user) {
+                    $user = json_decode($user, true);
+                    return Arr::get($user, 'user_info', json_encode($user));
+                })
+                ->toArray();
+            $this->sendPresenceAdd($event, $channel, Arr::get(json_decode($channelData, true), 'user_info'));
+        } else {
+            $this->subscriptionRepository->subscribeToChannel($event->getConnectionId(), $channel);
+            $data = [];
+        }
 
         $this->sendMessage($event, $context, [
             'event' => 'subscription_succeeded',
             'channel' => $channel,
-            'data' => [],
+            'data' => $data,
         ]);
     }
 
@@ -138,6 +156,18 @@ protected function unsubscribe(WebsocketEvent $event, Context $context): void
         ]);
     }
 
+    public function sendPresenceDisconnectNotices(WebsocketEvent $event): void
+    {
+        $channels = $this->subscriptionRepository->getChannelsSubscribedToByConnectionId($event->getConnectionId());
+        $channels->filter(function ($info) {
+            return Str::startsWith(Arr::get($info, 'channel'), 'presence-');
+        })->each(function ($info) use ($event) {
+            $channel = Arr::get($info, 'channel');
+            $userData = json_decode(Arr::get($info, 'userData'), true);
+            $this->sendPresenceRemove($event, $channel, Arr::get($userData, 'user_info'));
+        });
+    }
+
     public function broadcastToChannel(WebsocketEvent $event, Context $context): void
     {
         $skipConnectionId = $event->getConnectionId();
@@ -158,6 +188,34 @@ public function broadcastToChannel(WebsocketEvent $event, Context $context): voi
             ->each(fn (string $connectionId) => $this->sendMessageToConnection($connectionId, $data));
     }
 
+    public function sendPresenceAdd(WebsocketEvent $event, string $channel, array $data): void
+    {
+        $skipConnectionId = $event->getConnectionId();
+        $eventBody = json_decode($event->getBody(), true);
+        $data = json_encode([
+            'event'=>'member_added',
+            'channel'=>$channel,
+            'data'=>$data
+        ]) ?: '';
+        $this->subscriptionRepository->getConnectionIdsForChannel($channel)
+            ->reject(fn ($connectionId) => $connectionId === $skipConnectionId)
+            ->each(fn (string $connectionId) => $this->sendMessageToConnection($connectionId, $data));
+    }
+
+    public function sendPresenceRemove(WebsocketEvent $event, string $channel, array $data): void
+    {
+        $skipConnectionId = $event->getConnectionId();
+        $eventBody = json_decode($event->getBody(), true);
+        $data = json_encode([
+            'event'=>'member_removed',
+            'channel'=>$channel,
+            'data'=>$data
+        ]) ?: '';
+        $this->subscriptionRepository->getConnectionIdsForChannel($channel)
+            ->reject(fn ($connectionId) => $connectionId === $skipConnectionId)
+            ->each(fn (string $connectionId) => $this->sendMessageToConnection($connectionId, $data));
+    }
+
     public function sendMessage(WebsocketEvent $event, Context $context, array $data): void
     {
         $this->connectionRepository->sendMessage($event->getConnectionId(), json_encode($data, JSON_THROW_ON_ERROR));
@@ -168,7 +226,7 @@ protected function sendMessageToConnection(string $connectionId, string $data):
         try {
             $this->connectionRepository->sendMessage($connectionId, $data);
         } catch (ApiGatewayManagementApiException $exception) {
-            if ($exception->getAwsErrorCode() === 'GoneException') {
+            if ($exception->getStatusCode() === Response::HTTP_GONE) {
                 $this->subscriptionRepository->clearConnection($connectionId);
                 return;
             }

diff --git a/src/SubscriptionRepository.php b/src/SubscriptionRepository.php
@@ -41,6 +41,43 @@ public function getConnectionIdsForChannel(string ...$channels): Collection
             ->unique();
     }
 
+    public function getUserListForPresenceChannel(string ...$channels): Collection
+    {
+        $promises = collect($channels)->map(fn ($channel) => $this->dynamoDb->queryAsync([
+            'TableName' => $this->table,
+            'IndexName' => 'lookup-by-channel',
+            'KeyConditionExpression' => 'channel = :channel',
+            'ExpressionAttributeValues' => [
+                ':channel' => ['S' => $channel],
+            ],
+        ]))->toArray();
+
+        $responses = Utils::all($promises)->wait();
+
+        return collect($responses)
+             ->flatmap(fn (\Aws\Result $result): array => $result['Items'])
+            ->map(fn (array $item): string => Arr::get($item, 'userData.S', ''))
+            ->unique();
+    }
+
+    public function getChannelsSubscribedToByConnectionId(string $connectionId): Collection
+    {
+        $response = $this->dynamoDb->query([
+            'TableName' => $this->table,
+            'KeyConditionExpression' => 'connectionId = :connectionId',
+            'ExpressionAttributeValues' => [
+                ':connectionId' => ['S' => $connectionId],
+            ],
+        ]);
+        return collect(Arr::get($response, 'Items', []))
+            ->transform(function ($item) {
+                return [
+                    'channel'=>Arr::get($item, 'channel.S'),
+                    'userData'=>Arr::get($item, 'userData.S'),
+                ];
+            });
+    }
+
     public function clearConnection(string $connectionId): void
     {
         $response = $this->dynamoDb->query([
@@ -86,4 +123,16 @@ public function unsubscribeFromChannel(string $connectionId, string $channel): v
             ],
         ]);
     }
+
+    public function subscribeToPresenceChannel(string $connectionId, string $userData, string $channel): void
+    {
+        $this->dynamoDb->putItem([
+            'TableName' => $this->table,
+            'Item' => [
+                'connectionId' => ['S' => $connectionId],
+                'userData' => ['S' => $userData],
+                'channel' => ['S' => $channel],
+            ],
+        ]);
+    }
 }
diff --git a/tests/HandlerTest.php b/tests/HandlerTest.php
@@ -12,6 +12,7 @@
 use GuzzleHttp\Psr7\Response;
 use Mockery\Mock;
 use Psr\Http\Message\RequestInterface;
+use Symfony\Component\HttpFoundation\Response as SymfonyResponse;
 
 it('can subscribe to open channels', function () {
     app()->instance(SubscriptionRepository::class, Mockery::mock(SubscriptionRepository::class, function ($mock) {
@@ -113,7 +114,85 @@
     ], $context);
 });
 
-it('handles dropped connections', function () {
+it('leaves presence channels', function () {
+    app()->instance(SubscriptionRepository::class, Mockery::mock(SubscriptionRepository::class, function ($mock) {
+        /** @var Mock $mock */
+        $mock->shouldReceive('getChannelsSubscribedToByConnectionId')->withArgs(function (string $connectionId): bool {
+            return $connectionId === 'connection-id-1';
+        })->once()
+        ->andReturn(collect([
+            [
+                'channel'=>'presence-channel',
+                'userData'=>json_encode(['user_info'=>['the user info']]),
+            ],
+            [
+                'channel'=>'other-channel',
+            ]
+        ]));
+        $mock->shouldReceive('getConnectionIdsForChannel')->withArgs(function (string $channel) {
+            return $channel === 'presence-channel';
+        })->once()
+        ->andReturn(collect(['connection-id-1', 'connection-id-2']));
+        $mock->shouldReceive('clearConnection')->withArgs(function (string $connectionId) {
+            return $connectionId === 'connection-id-1';
+        })->once();
+    }));
+
+    app()->instance(ConnectionRepository::class, Mockery::mock(ConnectionRepository::class, function ($mock) {
+        /** @var Mock $mock */
+        $mock->shouldReceive('sendMessage')->withArgs(function (string $connectionId, string $data): bool {
+            return $connectionId === 'connection-id-2' and $data === '{"event":"member_removed","channel":"presence-channel","data":["the user info"]}';
+        })->once();
+    }));
+
+    /** @var Handler $handler */
+    $handler = app(Handler::class);
+
+    $context = new Context('request-id-1', 50_000, 'function-arn', 'trace-id-1');
+
+    $handler->handle([
+        'requestContext' => [
+            'routeKey' => 'my-test-route-key',
+            'eventType' => 'DISCONNECT',
+            'connectionId' => 'connection-id-1',
+            'domainName' => 'test-domain',
+            'apiId' => 'api-id-1',
+            'stage' => 'stage-test',
+        ],
+        'body' => json_encode(['event' => 'disconnect']),
+    ], $context);
+});
+
+it('handles dropped connections with HTTP_GONE', function () {
+    $mock = new MockHandler();
+
+    $mock->append(function (CommandInterface $cmd, RequestInterface $req) {
+        $mock = Mockery::mock(SymfonyResponse::class, function ($mock) {
+            $mock->shouldReceive('getStatusCode')
+                ->andReturn(SymfonyResponse::HTTP_GONE);
+        });
+        return new  ApiGatewayManagementApiException('', $cmd, [
+            'response' => $mock
+        ]);
+    });
+
+    /** @var SubscriptionRepository */
+    $subscriptionRepository = Mockery::mock(SubscriptionRepository::class, function ($mock) {
+        /** @var Mock $mock */
+        $mock->shouldReceive('clearConnection')->withArgs(function (string $connectionId): bool {
+            return $connectionId === 'dropped-connection-id-1234';
+        })->once();
+    });
+
+    $config = config('laravel-echo-api-gateway');
+
+    /** @var ConnectionRepository */
+    $connectionRepository = new ConnectionRepository($subscriptionRepository, array_merge_recursive(['connection' => ['handler' => $mock]], $config));
+
+    $connectionRepository->sendMessage('dropped-connection-id-1234', 'test-message');
+});
+
+it('handles dropped connections with GoneException', function () {
     $mock = new MockHandler();
 
     $mock->append(function (CommandInterface $cmd, RequestInterface $req) {