feat(proxy-engine): add Rust-based outbound calling, WebRTC bridging, and voicemail handling

rust/crates/proxy-engine/src/voicemail.rs

@@ -0,0 +1,137 @@
+//! Voicemail session — answer → play greeting → beep → record → done.
+
+use crate::audio_player::{play_beep, play_wav_file};
+use crate::ipc::{emit_event, OutTx};
+use crate::recorder::Recorder;
+use std::net::SocketAddr;
+use std::sync::Arc;
+use tokio::net::UdpSocket;
+
+/// Run a voicemail session on an RTP port.
+///
+/// 1. Plays the greeting WAV file to the caller
+/// 2. Plays a beep tone
+/// 3. Records the caller's message until BYE or max duration
+///
+/// The RTP receive loop is separate — it feeds packets to the recorder
+/// via the returned channel.
+pub async fn run_voicemail_session(
+    rtp_socket: Arc<UdpSocket>,
+    provider_media: SocketAddr,
+    codec_pt: u8,
+    greeting_wav: Option<String>,
+    recording_path: String,
+    max_recording_ms: u64,
+    call_id: String,
+    caller_number: String,
+    out_tx: OutTx,
+) {
+    let ssrc: u32 = rand::random();
+
+    emit_event(
+        &out_tx,
+        "voicemail_started",
+        serde_json::json!({
+            "call_id": call_id,
+            "caller_number": caller_number,
+        }),
+    );
+
+    // Step 1: Play greeting.
+    let mut next_seq: u16 = 0;
+    let mut next_ts: u32 = 0;
+
+    if let Some(wav_path) = &greeting_wav {
+        match play_wav_file(wav_path, rtp_socket.clone(), provider_media, codec_pt, ssrc).await {
+            Ok(frames) => {
+                next_seq = frames as u16;
+                next_ts = frames * crate::rtp::rtp_clock_increment(codec_pt);
+            }
+            Err(e) => {
+                emit_event(
+                    &out_tx,
+                    "voicemail_error",
+                    serde_json::json!({ "call_id": call_id, "error": format!("greeting: {e}") }),
+                );
+            }
+        }
+    }
+
+    // Step 2: Play beep (1kHz, 500ms).
+    match play_beep(
+        rtp_socket.clone(),
+        provider_media,
+        codec_pt,
+        ssrc,
+        next_seq,
+        next_ts,
+        1000,
+        500,
+    )
+    .await
+    {
+        Ok((_seq, _ts)) => {}
+        Err(e) => {
+            emit_event(
+                &out_tx,
+                "voicemail_error",
+                serde_json::json!({ "call_id": call_id, "error": format!("beep: {e}") }),
+            );
+        }
+    }
+
+    // Step 3: Record incoming audio.
+    let recorder = match Recorder::new(&recording_path, codec_pt, Some(max_recording_ms)) {
+        Ok(r) => r,
+        Err(e) => {
+            emit_event(
+                &out_tx,
+                "voicemail_error",
+                serde_json::json!({ "call_id": call_id, "error": format!("recorder: {e}") }),
+            );
+            return;
+        }
+    };
+
+    // Receive RTP and feed to recorder.
+    let result = record_from_socket(rtp_socket, recorder, max_recording_ms).await;
+
+    // Step 4: Done — emit recording result.
+    emit_event(
+        &out_tx,
+        "recording_done",
+        serde_json::json!({
+            "call_id": call_id,
+            "file_path": result.file_path,
+            "duration_ms": result.duration_ms,
+            "caller_number": caller_number,
+        }),
+    );
+}
+
+/// Read RTP packets from the socket and feed them to the recorder.
+/// Returns when the socket errors out (BYE closes the call/socket)
+/// or max duration is reached.
+async fn record_from_socket(
+    socket: Arc<UdpSocket>,
+    mut recorder: Recorder,
+    max_ms: u64,
+) -> crate::recorder::RecordingResult {
+    let mut buf = vec![0u8; 65535];
+    let deadline = tokio::time::Instant::now() + tokio::time::Duration::from_millis(max_ms + 2000);
+
+    loop {
+        let timeout = tokio::time::timeout_at(deadline, socket.recv_from(&mut buf));
+        match timeout.await {
+            Ok(Ok((n, _addr))) => {
+                if !recorder.process_rtp(&buf[..n]) {
+                    break; // Max duration reached.
+                }
+            }
+            Ok(Err(_)) => break,     // Socket error (closed).
+            Err(_) => break,          // Timeout (max duration + grace).
+        }
+    }
+
+    recorder.stop()
+}