Placeholder code for DAVE protocol

See https://discord.com/developers/docs/topics/voice-connections#indicating-dave-protocol-support

This code does not add any additional functionality other than the absolute basic requirements outlined in the change-log. I have no idea how the library should implement DAVE and I'm not familiar with how the library processes voice data, but hopefully someone will eventually come along who knows how to finish this up.

src/Discord/Voice/VoiceClient.php

@@ -559,6 +559,39 @@ public function handleWebSocketConnection(WebSocket $ws): void
                     $sendHeartbeat();
                     $this->heartbeat = $this->loop->addPeriodicTimer($this->heartbeat_interval / 1000, $sendHeartbeat);
                     break;
+                case Op::VOICE_DAVE_PREPARE_TRANSITION:
+                    $this->handleDavePrepareTransition($data);
+                    break;
+                case Op::VOICE_DAVE_EXECUTE_TRANSITION:
+                    $this->handleDaveExecuteTransition($data);
+                    break;
+                case Op::VOICE_DAVE_TRANSITION_READY:
+                    $this->handleDaveTransitionReady($data);
+                    break;
+                case Op::VOICE_DAVE_PREPARE_EPOCH:
+                    $this->handleDavePrepareEpoch($data);
+                    break;
+                case Op::VOICE_DAVE_MLS_EXTERNAL_SENDER:
+                    $this->handleDaveMlsExternalSender($data);
+                    break;
+                case Op::VOICE_DAVE_MLS_KEY_PACKAGE:
+                    $this->handleDaveMlsKeyPackage($data);
+                    break;
+                case Op::VOICE_DAVE_MLS_PROPOSALS:
+                    $this->handleDaveMlsProposals($data);
+                    break;
+                case Op::VOICE_DAVE_MLS_COMMIT_WELCOME:
+                    $this->handleDaveMlsCommitWelcome($data);
+                    break;
+                case Op::VOICE_DAVE_MLS_ANNOUNCE_COMMIT_TRANSITION:
+                    $this->handleDaveMlsAnnounceCommitTransition($data);
+                    break;
+                case Op::VOICE_DAVE_MLS_WELCOME:
+                    $this->handleDaveMlsWelcome($data);
+                    break;
+                case Op::VOICE_DAVE_MLS_INVALID_COMMIT_WELCOME:
+                    $this->handleDaveMlsInvalidCommitWelcome($data);
+                    break;
             }
         });
 
@@ -1470,6 +1503,115 @@ protected function handleAudioData(string $message): void
         $decoder->stdin->write((string) $buff);
     }
 
+    private function handleDavePrepareTransition($data)
+    {
+        $this->logger->debug('DAVE Prepare Transition', ['data' => $data]);
+        // Prepare local state necessary to perform the transition
+        $this->send([
+            'op' => Op::VOICE_DAVE_TRANSITION_READY,
+            'd' => [
+                'transition_id' => $data->d->transition_id,
+            ],
+        ]);
+    }
+
+    private function handleDaveExecuteTransition($data)
+    {
+        $this->logger->debug('DAVE Execute Transition', ['data' => $data]);
+        // Execute the transition
+        // Update local state to reflect the new protocol context
+    }
+
+    private function handleDaveTransitionReady($data)
+    {
+        $this->logger->debug('DAVE Transition Ready', ['data' => $data]);
+        // Handle transition ready state
+    }
+
+    private function handleDavePrepareEpoch($data)
+    {
+        $this->logger->debug('DAVE Prepare Epoch', ['data' => $data]);
+        // Prepare local MLS group with parameters appropriate for the DAVE protocol version
+        $this->send([
+            'op' => Op::VOICE_DAVE_MLS_KEY_PACKAGE,
+            'd' => [
+                'epoch_id' => $data->d->epoch_id,
+                'key_package' => $this->generateKeyPackage(),
+            ],
+        ]);
+    }
+
+    private function handleDaveMlsExternalSender($data)
+    {
+        $this->logger->debug('DAVE MLS External Sender', ['data' => $data]);
+        // Handle external sender public key and credential
+    }
+
+    private function handleDaveMlsKeyPackage($data)
+    {
+        $this->logger->debug('DAVE MLS Key Package', ['data' => $data]);
+        // Handle MLS key package
+    }
+
+    private function handleDaveMlsProposals($data)
+    {
+        $this->logger->debug('DAVE MLS Proposals', ['data' => $data]);
+        // Handle MLS proposals
+        $this->send([
+            'op' => Op::VOICE_DAVE_MLS_COMMIT_WELCOME,
+            'd' => [
+                'commit' => $this->generateCommit(),
+                'welcome' => $this->generateWelcome(),
+            ],
+        ]);
+    }
+
+    private function handleDaveMlsCommitWelcome($data)
+    {
+        $this->logger->debug('DAVE MLS Commit Welcome', ['data' => $data]);
+        // Handle MLS commit and welcome messages
+    }
+
+    private function handleDaveMlsAnnounceCommitTransition($data)
+    {
+        // Handle MLS announce commit transition
+        $this->logger->debug('DAVE MLS Announce Commit Transition', ['data' => $data]);
+    }
+
+    private function handleDaveMlsWelcome($data)
+    {
+        // Handle MLS welcome message
+        $this->logger->debug('DAVE MLS Welcome', ['data' => $data]);
+    }
+
+    private function handleDaveMlsInvalidCommitWelcome($data)
+    {
+        $this->logger->debug('DAVE MLS Invalid Commit Welcome', ['data' => $data]);
+        // Handle invalid commit or welcome message
+        // Reset local group state and generate a new key package
+        $this->send([
+            'op' => Op::VOICE_DAVE_MLS_KEY_PACKAGE,
+            'd' => [
+                'key_package' => $this->generateKeyPackage(),
+            ],
+        ]);
+    }
+
+    private function generateKeyPackage()
+    {
+        // Generate and return a new MLS key package
+    }
+
+    private function generateCommit()
+    {
+        // Generate and return an MLS commit message
+    }
+
+    private function generateWelcome()
+    {
+        // Generate and return an MLS welcome message
+    }
+
     /**
      * Returns whether the voice client is ready.
      *