add dedicated RealtimeSIP client

Author: janligudzinski

src/realtime/api.rs

@@ -7,6 +7,8 @@ use tokio_tungstenite::{
     MaybeTlsStream, WebSocketStream,
 };
 
+pub mod sip;
+
 const WSS_URL: &str = "wss://api.openai.com/v1/realtime";
 
 pub struct RealtimeClient {

src/realtime/api/sip.rs

@@ -0,0 +1,43 @@
+use super::*;
+
+/// Intended for connecting to an already existing Realtime session spawned by accepting an incoming SIP call from e.g. Twilio.
+pub struct RealtimeSipClient {
+    pub wss_url: String,
+    pub api_key: String,
+    pub call_id: String,
+}
+
+impl RealtimeSipClient {
+    pub fn new(api_key: String, call_id: String) -> Self {
+        let wss_url = std::env::var("WSS_URL").unwrap_or_else(|_| WSS_URL.to_owned());
+        Self::new_with_endpoint(wss_url, api_key, call_id)
+    }
+
+    pub fn new_with_endpoint(wss_url: String, api_key: String, call_id: String) -> Self {
+        Self {
+            wss_url,
+            api_key,
+            call_id,
+        }
+    }
+
+    pub async fn connect(
+        &self,
+    ) -> Result<
+        (
+            SplitSink<WebSocketStream<MaybeTlsStream<TcpStream>>, Message>,
+            SplitStream<WebSocketStream<MaybeTlsStream<TcpStream>>>,
+        ),
+        Box<dyn std::error::Error>,
+    > {
+        let url = format!("{}?callId={}", self.wss_url, self.call_id);
+        let mut request = url.into_client_request()?;
+        let api_key = self.api_key.clone();
+        request
+            .headers_mut()
+            .insert("Authorization", format!("Bearer {api_key}").parse()?);
+        let (ws_stream, _) = connect_async(request).await?;
+        let (write, read) = ws_stream.split();
+        Ok((write, read))
+    }
+}