A record may leave its lists some time after reaching a state: leaves_after

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GT37Z1Xtfd9pUuQtMTg6Yt

src/deadlines.rs

@@ -37,6 +37,55 @@ pub async fn run(state: AppState) {
     }
 }
 
+/// Records leaving their list: once a record has been in a state with
+/// `leaves_after` for that long, it is taken out of the bucket. Not a
+/// move - nothing is decided, no mail goes - and the event log keeps
+/// the record. Every minute, over the buckets that use it and no
+/// others.
+pub async fn run_leaving(state: AppState) {
+    let mut tick = tokio::time::interval(std::time::Duration::from_secs(60));
+    loop {
+        tick.tick().await;
+        if let Err(e) = sweep_leaving(&state).await {
+            tracing::warn!(error = %e, "leaving sweep failed");
+        }
+    }
+}
+
+/// Whether a record has stayed out its time in the state it is in.
+pub fn has_left(schema: &crate::aggregates::AggregateSchema, answer: &Answer, now_ms: i64) -> bool {
+    schema
+        .leaves_for_state
+        .get(&answer.state)
+        .is_some_and(|leaves| now_ms >= waiting_since(answer) + leaves.millis())
+}
+
+pub async fn sweep_leaving(state: &AppState) -> anyhow::Result<()> {
+    let now_ms = chrono::Utc::now().timestamp_millis();
+    let aggregates = state.aggregates.load();
+    for schema in aggregates.values().filter(|s| !s.leaves_for_state.is_empty()) {
+        let Ok(store) = state.jetstream.get_key_value(&schema.bucket).await else { continue };
+        let keys: Vec<String> = {
+            use futures::TryStreamExt;
+            match store.keys().await {
+                Ok(keys) => keys.try_collect().await.unwrap_or_default(),
+                Err(_) => continue,
+            }
+        };
+        for id in keys {
+            let Ok(Some(bytes)) = store.get(&id).await else { continue };
+            let Ok(answer) = serde_json::from_slice::<Answer>(&bytes) else { continue };
+            if has_left(schema, &answer, now_ms) {
+                match store.delete(&id).await {
+                    Ok(()) => tracing::info!(bucket = %schema.bucket, id, state = %answer.state, "a record left its list"),
+                    Err(e) => tracing::warn!(bucket = %schema.bucket, id, "a record could not leave its list: {e}"),
+                }
+            }
+        }
+    }
+    Ok(())
+}
+
 /// When a record entered the state it is in now. A record nobody has
 /// moved has been waiting since it was sent.
 fn waiting_since(answer: &Answer) -> i64 {
@@ -150,6 +199,21 @@ aggregates:
         }
     }
 
+    #[test]
+    fn a_record_leaves_its_list_when_its_time_in_the_state_is_up() {
+        let s = schema(
+            "aggregates:\n  - bucket: people\n    initial: open\n    states:\n      open: { event: shown }\n      gone: { event: gone, leaves_after: { minutes: 10 } }\n    transitions:\n      open: [gone]\n",
+        );
+        let t = 1_000_000_000_000;
+        let mut answer = waiting("gone", t - 60 * 60 * 1000);
+        answer.decided_ms = Some(t);
+        assert!(!has_left(&s, &answer, t + 9 * 60 * 1000), "measured from entering the state, not from sending");
+        assert!(has_left(&s, &answer, t + 10 * 60 * 1000));
+        // A state without it keeps its records.
+        assert!(!has_left(&s, &waiting("open", 0), t));
+        assert!(crate::aggregates::parse_aggregates_yaml("aggregates:\n  - bucket: p\n    initial: open\n    states:\n      open: { event: o, leaves_after: {} }\n    transitions: {}\n").is_err());
+    }
+
     #[test]
     fn a_deadline_comes_due_the_day_it_says_and_not_before() {
         let s = schema(HEARINGS);