Issue #345: AI Denoise in the activity stack

While a photo's AI Denoise picture is being made or waits its turn, the
stack shows "AI Denoise" with the running photo's tiles as a percentage
and its file name (no cross: what is made follows the Denoise amounts and
Settings). The row goes when the queue is idle.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/cmd/denoise.rs

@@ -614,6 +614,7 @@ fn status(s: &mut Session, p: &Value) -> Result<Value> {
 /// `denoise.pump {pace?}`: cheap to call every frame. Takes in what the background job has finished and keeps one going.
 fn pump(s: &mut Session, p: &Value) -> Result<Value> {
     s.denoise_pump(Pace::parse(p.get("pace").and_then(Value::as_str)));
+    s.denoise_track();
     Ok(json!({
         "active": s.denoise.active.is_some(),
         "running": s.denoise_running_json(),

crates/engine/src/denoise.rs

@@ -890,6 +890,8 @@ pub(crate) struct State {
     pub generation: u64,
     /// Photos made since the session started.
     made: u64,
+    /// AI Denoise's row in the activity stack, while a photo is being made or waits its turn.
+    task: Option<crate::activity::TaskGuard>,
 }
 
 impl Default for State {
@@ -909,6 +911,7 @@ impl Default for State {
             failed: HashMap::new(),
             generation: 0,
             made: 0,
+            task: None,
         }
     }
 }
@@ -1354,6 +1357,31 @@ impl Session {
         self.denoise.running.is_some() || (!self.denoise.queue.is_empty() && self.denoise.active.is_some())
     }
 
+    /// Keep AI Denoise's row in the activity stack up to date (each `denoise.pump`): there while a photo is being made or
+    /// waits its turn, with the running photo's tiles and its file name; gone when the queue is idle. It has no ✕: what is
+    /// made follows the photos' Denoise amounts and Settings ▸ AI Denoise.
+    pub(crate) fn denoise_track(&mut self) {
+        if !self.denoise_busy() {
+            self.denoise.task = None;
+            return;
+        }
+        let task = self.denoise.task.get_or_insert_with(|| {
+            let t = self.activity.start("denoise", "AI Denoise", crate::activity::Cancel::No);
+            t.set_unit(crate::activity::Unit::Percent);
+            t
+        });
+        match &self.denoise.running {
+            Some(r) => {
+                task.progress(r.progress.done.load(Ordering::Relaxed) as u64, r.progress.total.load(Ordering::Relaxed) as u64);
+                task.detail(self.catalog.photo(r.photo).map_or("", |p| p.file_name.as_str()));
+            }
+            None => {
+                task.progress(0, 0);
+                task.detail("");
+            }
+        }
+    }
+
     /// Seconds the running job has been going, and its progress.
     pub(crate) fn denoise_running_json(&self) -> Value {
         match &self.denoise.running {

crates/engine/src/tests_denoise.rs

@@ -757,3 +757,35 @@ fn the_denoise_switch_validates_arguments_and_accepts_explicit_targets_without_s
     drop(x.s);
     let _ = std::fs::remove_dir_all(x.dir);
 }
+
+#[test]
+fn denoise_row_while_queue_is_busy() {
+    let mut x = setup("activity", true);
+    let rows = |s: &Session| s.activity.list().into_iter().filter(|t| t.kind == "denoise").collect::<Vec<_>>();
+    let r = x.s.execute("denoise.pump", &json!({"pace": "full"})).unwrap();
+    assert!(rows(&x.s).is_empty(), "nothing to make, no row: {r}");
+    set_amount(&mut x.s, 100.0);
+    let mut shown = false;
+    for _ in 0..600 {
+        let r = x.s.execute("denoise.pump", &json!({"pace": "full"})).unwrap();
+        let rows = rows(&x.s);
+        // (what the pump left running or queued is what the row reflects until the next pump)
+        if x.s.denoise_busy() {
+            assert_eq!(rows.len(), 1, "{r}");
+            assert_eq!((rows[0].label.as_str(), rows[0].cancellable, rows[0].unit), ("AI Denoise", false, crate::activity::Unit::Percent), "{r}");
+            if !r["running"].is_null() {
+                assert_eq!(rows[0].detail, "ramp.dng", "{r}");
+            }
+            shown = true;
+        } else {
+            assert!(rows.is_empty(), "{r}");
+        }
+        if r["ready"].as_u64() >= Some(1) {
+            break;
+        }
+        std::thread::sleep(std::time::Duration::from_millis(50));
+    }
+    assert!(shown, "the photo never showed a row");
+    assert!(rows(&x.s).is_empty(), "the row goes once the photo is made");
+    let _ = std::fs::remove_dir_all(&x.dir);
+}