Storylines: the same site told several ways, one per visitor, counted

Any text a person reads may be a list, one entry per storyline, every
list the same length. A visitor is given one storyline for the whole
site and reads it on every page and in every mail about their case.
Records and events carry the storyline; GET /report gives counts per
bucket, storyline and state, and nothing else.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GT37Z1Xtfd9pUuQtMTg6Yt

src/report.rs

@@ -0,0 +1,53 @@
+//! What the storylines did, as numbers and nothing else.
+//!
+//! `GET /report` answers with a count per bucket, per storyline, per
+//! state: how many cases each storyline brought in and where they got
+//! to. That is the whole of what the storylines are compared on. No
+//! record, no field, no address, no time leaves the site: a storyline
+//! is assigned evenly, so the counts are the comparison, and the
+//! trainer (`portal-trainer report`) reads them to say which words
+//! worked. Public, since a count is what a public list already shows.
+#![cfg(feature = "ssr")]
+
+use std::collections::BTreeMap;
+
+use serde::{Deserialize, Serialize};
+
+/// The report: the site's storylines, and per bucket the count of
+/// records by storyline and state.
+#[derive(Clone, Debug, Default, Serialize, Deserialize)]
+pub struct Report {
+    pub storylines: usize,
+    /// bucket -> storyline (as a string, JSON's way) -> state -> count
+    pub buckets: BTreeMap<String, BTreeMap<String, BTreeMap<String, u64>>>,
+}
+
+pub async fn gather(state: &crate::server::AppState) -> Report {
+    let mut report = Report { storylines: state.questions.load().arity(), buckets: BTreeMap::new() };
+    let aggregates = state.aggregates.load();
+    for bucket in aggregates.keys() {
+        // The runtime's own buckets are not the site's offers.
+        if bucket.starts_with("portal_") {
+            continue;
+        }
+        let Ok(store) = state.jetstream.get_key_value(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,
+            }
+        };
+        let counts = report.buckets.entry(bucket.clone()).or_default();
+        for key in keys {
+            let Ok(Some(bytes)) = store.get(&key).await else { continue };
+            let Ok(answer) = serde_json::from_slice::<crate::answers::Answer>(&bytes) else { continue };
+            *counts.entry(answer.storyline.to_string()).or_default().entry(answer.state).or_default() += 1;
+        }
+    }
+    report
+}
+
+pub async fn handler(axum::extract::State(state): axum::extract::State<crate::server::AppState>) -> axum::Json<Report> {
+    axum::Json(gather(&state).await)
+}