refactor: resync with qbqt baseline and restore genre browser

rust/src/player/mod.rs

@@ -141,7 +141,7 @@ fn player_loop(rx: std::sync::mpsc::Receiver<PlayerCommand>, status: PlayerStatu
                 match rx.recv_timeout(Duration::from_millis(100)) {
                     Ok(PlayerCommand::Play(info)) => break info,
                     Ok(PlayerCommand::QueueNext(info)) => {
-                        // If completely idle and get QueueNext, treat as Play
+                        // If we are completely idle and get QueueNext, treat as Play
                         break info;
                     }
                     Ok(PlayerCommand::Stop) => {
@@ -155,7 +155,7 @@ fn player_loop(rx: std::sync::mpsc::Receiver<PlayerCommand>, status: PlayerStatu
                     Ok(PlayerCommand::SetVolume(v)) => {
                         status.volume.store(v, Ordering::Relaxed);
                     }
-                    Ok(_) => {}
+                    Ok(_) => {} // Ignore Pause/Resume when idle
                     Err(RecvTimeoutError::Timeout) => {}
                     Err(RecvTimeoutError::Disconnected) => break 'outer,
                 }
@@ -176,9 +176,11 @@ fn player_loop(rx: std::sync::mpsc::Receiver<PlayerCommand>, status: PlayerStatu
         status.position_secs.store(0, Ordering::Relaxed);
         paused.store(false, Ordering::SeqCst);
 
+        // TrackInfo now directly passes the prefetch_data (if it exists) to the decoder
         match decoder::play_track_inline(info, &status, &paused, &mut audio_output, &rx) {
             Ok(Some(NextAction::Play(next_track))) => {
                 pending_action = Some(NextAction::Play(next_track));
+                // Interrupted by a manual play, no need to tell C++ to advance the queue
             }
             Ok(Some(NextAction::Transition(next_track))) => {
                 pending_action = Some(NextAction::Play(next_track));

rust/src/player/output.rs

@@ -3,7 +3,7 @@ use cpal::{
     traits::{DeviceTrait, HostTrait, StreamTrait},
     StreamConfig,
 };
-use rb::{RbConsumer, RbProducer, SpscRb, RB};
+use rb::{RbConsumer, RbInspector, RbProducer, SpscRb, RB};
 use std::sync::{
     atomic::{AtomicBool, Ordering},
     Arc,
@@ -13,6 +13,7 @@ use symphonia::core::audio::AudioBufferRef;
 const RING_BUFFER_SIZE: usize = 32 * 1024;
 
 pub struct AudioOutput {
+    _ring: SpscRb<f32>,
     ring_buf_producer: rb::Producer<f32>,
     _stream: cpal::Stream,
     pub sample_rate: u32,
@@ -50,6 +51,7 @@ impl AudioOutput {
         stream.play()?;
 
         Ok(Self {
+            _ring: ring,
             ring_buf_producer: producer,
             _stream: stream,
             sample_rate,
@@ -87,4 +89,13 @@ impl AudioOutput {
         }
         Ok(())
     }
+
+    pub fn flush(&self) {
+        // Wait until the ring buffer is fully emptied by cpal
+        while !self._ring.is_empty() {
+            std::thread::sleep(std::time::Duration::from_millis(10));
+        }
+        // Give the physical DAC an extra 100ms to output the last samples
+        std::thread::sleep(std::time::Duration::from_millis(100));
+    }
 }