From fc19a1430bc71276c74e9228bd41f7749b4fd104 Mon Sep 17 00:00:00 2001
From: Brandon Thomas <echelon@gmail.com>
Date: Sun, 26 Sep 2021 20:29:57 -0400
Subject: [PATCH] listen command

---
 Cargo.lock                     |  1 +
 Cargo.toml                     |  1 +
 src/twitch/websocket_client.rs | 36 ++++++++++++++++++++++++++++++++--
 src/util/mod.rs                |  4 +++-
 src/util/random_nonce.rs       | 24 +++++++++++++++++++++++
 5 files changed, 63 insertions(+), 3 deletions(-)
 create mode 100644 src/util/random_nonce.rs

diff --git a/Cargo.lock b/Cargo.lock
index 1f0d4e5015..3c3628861a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1300,6 +1300,7 @@ dependencies = [
  "easyenv",
  "futures-util",
  "log",
+ "rand",
  "reqwest",
  "rustls 0.20.0-beta2",
  "serde",
diff --git a/Cargo.toml b/Cargo.toml
index 0a57ac5219..af96cc2d8f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -46,6 +46,7 @@ twitch_oauth2 = "0.6.0-rc.2"
 anyhow = "1.0.44"
 easyenv = "0.0.6"
 log = "0.4.14"
+rand = "0.8.4"
 
 #[build-dependencies]
 
diff --git a/src/twitch/websocket_client.rs b/src/twitch/websocket_client.rs
index b8ece637eb..4c060a21b9 100644
--- a/src/twitch/websocket_client.rs
+++ b/src/twitch/websocket_client.rs
@@ -11,8 +11,9 @@ use tokio::net::TcpStream;
 use tokio;
 use tokio_tungstenite::tungstenite::Message;
 use tokio_tungstenite::{connect_async, WebSocketStream, MaybeTlsStream};
-use twitch_api2::pubsub::{Response, TopicData};
+use twitch_api2::pubsub::{Response, TopicData, Topic, Topics};
 use twitch_api2::pubsub;
+use crate::util::random_nonce::random_nonce;
 
 // Reference javascript Twitch Websocket client:
 // https://github.com/twitchdev/pubsub-javascript-sample/blob/main/main.js
@@ -179,6 +180,37 @@ impl TwitchWebsocketClient {
     Ok(())
   }
 
+  pub async fn listen<'t>(&mut self, auth_token: &str, topics: &'t [Topics]) -> AnyhowResult<()> {
+    //// We want to subscribe to moderator actions on channel with id 1234
+    //// as if we were a user with id 4321 that is moderator on the channel.
+    //let chat_mod_actions = pubsub::moderation::ChatModeratorActions {
+    //  user_id: 4321,
+    //  channel_id: 1234,
+    //}.into_topic();
+
+    //// Listen to follows as well
+    //let follows = pubsub::following::Following { channel_id: 1234 }.into_topic();
+
+    let mut socket = match self.socket {
+      None => return Err(anyhow!("not connected")),
+      Some(ref mut socket) => socket,
+    };
+
+    let nonce = random_nonce(128);
+
+    let command = pubsub::listen_command(
+      topics,
+      auth_token,
+      nonce.as_ref(),
+    )?;
+
+    debug!("Sending LISTEN");
+    let message = Message::Text(command);
+    socket.send(message).await?;
+
+    Ok(())
+  }
+
   pub fn is_connected(&self) -> bool {
     // TODO: This probably isn't accurate
     self.socket.is_some()
@@ -190,7 +222,7 @@ impl TwitchWebsocketClient {
       Some(ref mut socket) => socket,
     };
 
-    debug!("Sending ping");
+    debug!("Sending PING");
     let message = Message::Text(PING_COMMAND.to_string());
     socket.send(message).await?;
 
diff --git a/src/util/mod.rs b/src/util/mod.rs
index 0bb75d1b62..145df6fe0c 100644
--- a/src/util/mod.rs
+++ b/src/util/mod.rs
@@ -1 +1,3 @@
-pub mod anyhow_result;
\ No newline at end of file
+pub mod anyhow_result;
+pub mod random_nonce;
+
diff --git a/src/util/random_nonce.rs b/src/util/random_nonce.rs
new file mode 100644
index 0000000000..5f9034d3aa
--- /dev/null
+++ b/src/util/random_nonce.rs
@@ -0,0 +1,24 @@
+use rand::distributions::Alphanumeric;
+use rand::{thread_rng, Rng};
+
+/// Returns a random nonce for Twitch
+pub fn random_nonce(length: usize) -> String {
+  thread_rng()
+      .sample_iter(&Alphanumeric)
+      .take(length)
+      .map(char::from)
+      .collect()
+}
+
+#[cfg(test)]
+mod tests {
+  use crate::util::random_nonce::random_nonce;
+
+  #[test]
+  fn random_nonce_length() {
+    assert_eq(1, random_nonce(1).len());
+    assert_eq(10, random_nonce(10).len());
+    assert_eq(15, random_nonce(15).len());
+    assert_eq(64, random_nonce(64).len());
+  }
+}
\ No newline at end of file