From 6058ea488890267403f22362b35955035e5cc588 Mon Sep 17 00:00:00 2001
From: Amish Shah <amishshah.2k@gmail.com>
Date: Fri, 19 Jan 2018 17:45:37 +0000
Subject: [PATCH] Start voice receive rewrite

---
 src/client/voice/receiver/PacketHandler.js | 44 ++++++++++++++++++++++
 src/client/voice/receiver/Receiver.js      | 16 ++++++++
 src/client/voice/receiver/VoiceReceiver.js |  2 +-
 3 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 src/client/voice/receiver/PacketHandler.js
 create mode 100644 src/client/voice/receiver/Receiver.js

diff --git a/src/client/voice/receiver/PacketHandler.js b/src/client/voice/receiver/PacketHandler.js
new file mode 100644
index 000000000..b6eb09378
--- /dev/null
+++ b/src/client/voice/receiver/PacketHandler.js
@@ -0,0 +1,44 @@
+const nonce = Buffer.alloc(24);
+
+class PacketHandler {
+  constructor(receiver) {
+    this.receiver = receiver;
+  }
+
+  parseBuffer(buffer) {
+    // reuse nonce
+    buffer.copy(nonce, 0, 0, 12);
+
+    let packet = secretbox.methods.open(buffer.slice(12), nonce, this.receiver.connection.authentication.secretKey);
+    if (!packet) return Error('Failed to decrypt voice packet');
+    packet = Buffer.from(packet);
+  
+    // Strip RTP Header Extensions (one-byte only)
+    if (packet[0] === 0xBE && packet[1] === 0xDE && packet.length > 4) {
+      const headerExtensionLength = packet.readUInt16BE(2);
+      let offset = 4;
+      for (let i = 0; i < headerExtensionLength; i++) {
+        const byte = packet[offset];
+        offset++;
+        if (byte === 0) continue;
+        offset += 1 + (0b1111 & (byte >> 4));
+      }
+      while (packet[offset] === 0) offset++;
+      packet = packet.slice(offset);
+    }
+
+    return packet;
+  }
+
+  userFromSSRC(ssrc) { return this.receiver.connection.ssrcMap.get(ssrc); }
+
+  push(buffer) {
+    const ssrc = buffer.readUInt32BE(8);
+    const user = this.userFromSSRC(ssrc);
+    if (!user) return;
+    const opusPacket = this.parseBuffer(buffer);
+    if (opusPacket instanceof Error) return;
+  }
+}
+
+module.exports = PacketHandler;
diff --git a/src/client/voice/receiver/Receiver.js b/src/client/voice/receiver/Receiver.js
new file mode 100644
index 000000000..fa386c06a
--- /dev/null
+++ b/src/client/voice/receiver/Receiver.js
@@ -0,0 +1,16 @@
+const EventEmitter = require('events');
+
+class VoiceReceiver extends EventEmitter {
+  constructor(connection) {
+    super();
+    this.connection = connection;
+    this.packets = new PacketHandler(this); 
+    this.connection.sockets.udp.socket.on('message', buffer => this.packets.push(buffer));
+  }
+
+  createStream(user, pcm=false) {
+
+  }
+}
+
+module.exports = VoiceReceiver;
diff --git a/src/client/voice/receiver/VoiceReceiver.js b/src/client/voice/receiver/VoiceReceiver.js
index bc7a87061..07c4894bd 100644
--- a/src/client/voice/receiver/VoiceReceiver.js
+++ b/src/client/voice/receiver/VoiceReceiver.js
@@ -131,7 +131,7 @@ class VoiceReceiver extends EventEmitter {
     return stream;
   }
 
-  /**
+  /** 
    * Creates a readable stream for a user that provides PCM data while the user is speaking. When the user
    * stops speaking, the stream is destroyed. The stream is 32-bit signed stereo PCM at 48KHz.
    * @param {UserResolvable} user The user to create the stream for