Release 0.5.11

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

CHANGELOG.md

@@ -4,6 +4,14 @@ One line per change, grouped by the release that shipped it. Newest
 first. A release is a Cargo.toml bump plus a `v<version>` tag; the
 content repos pin the tag they run (see the end of this file).
 
+## 0.5.11 (2026-09-30)
+
+- Storylines (`src/content/variants.rs`, `docs/storylines.md`): 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 (the `portal_storyline` cookie, a year) and reads it on every page and in every mail about their case. What the machine reads - a field's `name`, `options`, states, groups, paths - never varies. The lint refuses a list of another length. Records and answer events carry `storyline`, and `GET /report` gives counts per bucket, per storyline, per state, and nothing else.
+
+## 0.5.10 (2026-09-30)
+
+- The lint lets an invite form collect a required `phone` in place of a required `email`: memberships know a person by number first.
+
 ## 0.5.9 (2026-09-30)
 
 - With memberships as the people backend and a Kanidm token still set, an invite makes the Kanidm account as well (no group, the one-time link in the mail): Kanidm makes people, portal makes members, and a site can switch to memberships before its sign-in provider is one everyone already has.
@@ -396,4 +404,4 @@ hosts now, since kasse's runner deploys its own instances.
 | redoal.com | ergo | `app@redoal-portal` | v0.5.2 |
 | westra.klingenbergbygg.no | kasse | `app@westra-portal` | v0.5.2 |
 | portal.klingenbergbygg.no | kasse | `app@klingenberg-portal` | v0.5.2 |
-| vel.klingenbergbygg.no | kasse | `tomtervel-portal-1` (podman, tomtervel/infrastructure) | v0.5.8 |
+| vel.klingenbergbygg.no | kasse | `tomtervel-portal-1` (podman, tomtervel/infrastructure) | v0.5.10, memberships |

Cargo.lock

@@ -3357,7 +3357,7 @@ dependencies = [
 
 [[package]]
 name = "portal"
-version = "0.5.9"
+version = "0.5.11"
 dependencies = [
  "anyhow",
  "arc-swap",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "portal"
-version = "0.5.9"
+version = "0.5.11"
 edition = "2021"
 
 [lib]

docs/README.md

@@ -11,6 +11,7 @@ engine does with it.
 | [Content reference](content-reference.md) | Every key a content repo may write, and what it does. |
 | [State machines](state-machines.md) | `aggregates.yaml`: stages, who moves a case, mail, deadlines, memberships. |
 | [Access](access.md) | How the Cedar policy is compiled from content, and who may ask it what. |
+| [Storylines](storylines.md) | The same site told several ways: lists of texts, one storyline per visitor, counted per storyline. |
 | [Memberships](memberships.md) | Groups kept by portal itself: a membership as a case, a person as a phone number first, and the provider only saying who. |
 | [Operations](operations.md) | Releasing, deploying, adding a site, environment variables. |
 | [Filesystem routes](design/filesystem-routes.md) | Why the `questions/` tree is the router. |

docs/SUMMARY.md

@@ -8,6 +8,7 @@
 - [Content reference](content-reference.md)
 - [State machines](state-machines.md)
 - [Access](access.md)
+- [Storylines](storylines.md)
 - [Memberships](memberships.md)
 - [Operations](operations.md)
 

docs/content-reference.md

@@ -38,6 +38,11 @@ mail:
 
 `mail.from` is required as soon as any state declares a mail.
 
+Any text a person reads (`name`, `description`, `label`,
+`placeholder`, a mail's `subject` and `body`, `consequence`,
+`encouragements`) may be a list instead of one string: one entry per
+[storyline](storylines.md), all lists the same length.
+
 ## A question
 
 One YAML file is one page.

docs/operations.md

@@ -130,6 +130,12 @@ then `GARAGE_S3_ENDPOINT`, `GARAGE_ACCESS_KEY`, `GARAGE_SECRET_KEY` and
 `GARAGE_UPLOADS_BUCKET` in that instance's env. Unset, an upload field
 fails closed rather than appearing to work and storing nowhere.
 
+## The report
+
+`GET /report` is public and answers with counts only: per bucket, per
+[storyline](storylines.md), per state. It is what the trainer reads to
+compare the storylines on what people did.
+
 ## The docs site
 
 These pages are [portal.uhhm.no](https://portal.uhhm.no): `docs/` built

docs/storylines.md

@@ -0,0 +1,60 @@
+# Storylines
+
+The same site, told two ways, and counted.
+
+Anywhere content says something to a person, it may say it in several
+ways by giving a list instead of one string:
+
+```yaml
+name: Vil du hjelpe til i nabolaget?
+description:
+  - Dugnad, 17. mai og komiteene trenger flere hender. Si hva du kan.
+  - Naboene gjør det meste selv. Her melder du deg til det du har lyst på.
+alternatives:
+  - name: [Bli med, Meld deg]
+    consequence: [[Send], [Meld meg]]
+```
+
+Each index is a *storyline*. A visitor is given one at their first
+request, kept in a cookie (`portal_storyline`) for a year, and reads
+that storyline on every page, in every button and in every mail the
+site sends them about their case. A single string is every storyline.
+
+## The rules
+
+- **Same length everywhere.** Every list of texts in the content has
+  the site's arity, so a storyline never has a hole in it. The lint
+  refuses a list of another length and names it.
+- **What varies is what a person reads:** `name`, `description`,
+  `label`, `placeholder`, `title`, a mail's `subject` and `body`, a
+  list's `empty` line, `consequence` and `encouragements` (those two as
+  lists of lists).
+- **What the machine reads never varies:** a field's `name` (the stored
+  key), a select's `options` (the stored values), states, groups,
+  paths, buckets.
+- **One storyline per site**, not per page. That is what makes it a
+  storyline rather than a scatter of variants: a warm front door leads
+  to a warm form and a warm mail.
+- A signed-in person keeps the storyline they had as a visitor.
+- A site that tells one storyline sets no cookie.
+
+## What is counted
+
+Every record and every answer event carries the storyline it came
+from (`storyline` on `Answer` and on `portal.answers.submitted`). The
+mail a case gets tells the same storyline, so a person who read the
+warm front door is not thanked in the plain voice.
+
+`GET /report` gives the counts, per bucket, per storyline, per state:
+
+```json
+{ "storylines": 2,
+  "buckets": { "hjelpebehov": { "0": { "open": 3, "ordnet": 9 },
+                                "1": { "open": 5, "ordnet": 14 } } } }
+```
+
+Storylines are assigned evenly, so those numbers are the comparison:
+which words brought more people to send, and how their cases went. No
+record, field, address or time leaves the site. The trainer reads this
+(`portal-trainer report`) next to what its personas scored offline, and
+the plan's `tones` are where the storylines are written.

src/announce.rs

@@ -84,6 +84,7 @@ pub async fn sweep(state: &AppState) -> anyhow::Result<()> {
                     EVENT_ALTERNATIVE,
                     &responses,
                     now_ms,
+                    0,
                 )
                 .await?;
                 tracing::info!(question = %q.id, "event record created");
@@ -137,6 +138,7 @@ pub async fn sweep(state: &AppState) -> anyhow::Result<()> {
                     alternative: SUMMARY_DUE_LABEL.to_string(),
                     responses: payload,
                     timestamp_ms: now_ms,
+                    storyline: 0,
                 },
             )
             .await?;

src/answers.rs

@@ -24,6 +24,10 @@ pub struct Answer {
     pub responses: serde_json::Value,
     pub state: String,
     pub submitted_ms: i64,
+    /// The storyline the record was sent from, so the mail it gets
+    /// tells the same one (see `content/variants.rs`).
+    #[serde(default)]
+    pub storyline: u32,
     #[serde(default)]
     pub decided_ms: Option<i64>,
     #[serde(default)]
@@ -64,6 +68,7 @@ pub async fn store_answer(
     alternative: &str,
     responses: &serde_json::Value,
     submitted_ms: i64,
+    storyline: u32,
 ) -> anyhow::Result<()> {
     let store = match js.get_key_value(bucket).await {
         Ok(store) => store,
@@ -89,6 +94,7 @@ pub async fn store_answer(
         responses: responses.clone(),
         state: initial_state,
         submitted_ms,
+        storyline,
         decided_ms: None,
         notes: Vec::new(),
         decided_by: None,
@@ -132,9 +138,11 @@ pub async fn transition_answers(
     use crate::server::AppState;
 
     let state = expect_context::<AppState>();
+    let storyline = crate::server::storyline::current().await;
     let alt = state
         .questions
         .load()
+        .at(storyline)
         .get(&question_id)
         .and_then(|q| q.alternatives.iter().find(|a| a.name == alternative).cloned())
         .ok_or_else(|| ServerFnError::new("unknown question or alternative"))?;
@@ -289,7 +297,7 @@ async fn apply_transition(
         .put(&item.item_id, data.into())
         .await
         .map_err(|e| ServerFnError::new(e.to_string()))?;
-    crate::mail::on_state(state, bucket, &item.item_id, &item.to, &answer.responses).await;
+    crate::mail::on_state(state, bucket, &item.item_id, &item.to, &answer.responses, answer.storyline).await;
     crate::people::on_state(state, bucket, &item.item_id, &item.to, &answer.responses).await;
     // An expired invite sent again: the move back is the asking.
     if bucket == crate::people::INVITES_BUCKET && item.to == OPEN_STATE {
@@ -307,6 +315,7 @@ async fn apply_transition(
         alternative: transition.label,
         responses: decision_payload_for_event,
         timestamp_ms: decided_ms,
+        storyline: answer.storyline,
     };
     emit_answer_submitted(&state.nats, &event)
         .await
@@ -417,7 +426,7 @@ pub async fn self_transition_answer(
         .put(&item_id, data.into())
         .await
         .map_err(|e| ServerFnError::new(e.to_string()))?;
-    crate::mail::on_state(&state, &self_transition.bucket, &item_id, &self_transition.to, &answer.responses).await;
+    crate::mail::on_state(&state, &self_transition.bucket, &item_id, &self_transition.to, &answer.responses, answer.storyline).await;
     crate::people::on_state(&state, &self_transition.bucket, &item_id, &self_transition.to, &answer.responses).await;
 
     let parent_hashes = vec![item_id.clone()];
@@ -429,6 +438,7 @@ pub async fn self_transition_answer(
         alternative: self_transition.label,
         responses: decision_payload_for_event,
         timestamp_ms: decided_ms,
+        storyline: answer.storyline,
     };
     emit_answer_submitted(&state.nats, &event)
         .await
@@ -456,6 +466,7 @@ mod tests {
                 responses: serde_json::json!({"name": "Ada"}),
                 state: OPEN_STATE.to_string(),
                 submitted_ms: 1_700_000_000_000,
+                storyline: 0,
                 decided_ms: None,
                 decided_by: None,
                 notes: Vec::new(),
@@ -467,6 +478,7 @@ mod tests {
                 responses: serde_json::json!({"name": "Grace"}),
                 state: "invited".to_string(),
                 submitted_ms: 1_700_000_001_000,
+                storyline: 0,
                 decided_ms: Some(1_700_000_002_000),
                 decided_by: Some("bl".to_string()),
                 notes: Vec::new(),

src/app.rs

@@ -2358,8 +2358,9 @@ pub async fn get_question(
     use crate::content::{fill_from_user, path_matches, resolve_question};
     use crate::server::AppState;
     let state = expect_context::<AppState>();
-    let questions = state.questions.load();
-    let Some(mut question) = resolve_question(&questions, &path) else {
+    let storylines = state.questions.load();
+    let questions = storylines.at(crate::server::storyline::current().await);
+    let Some(mut question) = resolve_question(questions, &path) else {
         return Ok(None);
     };
     let session: tower_sessions::Session = leptos_axum::extract().await?;
@@ -2401,7 +2402,7 @@ pub async fn get_question(
 pub async fn get_site() -> Result<SiteConfig, ServerFnError> {
     use crate::server::AppState;
     let state = expect_context::<AppState>();
-    let mut site = state.site.load().as_ref().clone();
+    let mut site = state.site.load().at(crate::server::storyline::current().await).clone();
     // Not content: whether this instance can serve tiles at all is its
     // own configuration, and the browser has to know before it decides
     // whether to draw a map or ask for two numbers.
@@ -2435,7 +2436,8 @@ pub async fn list_qualifying_questions(
         .map_err(|e| ServerFnError::new(e.to_string()))?;
 
     let now_ms = chrono::Utc::now().timestamp_millis();
-    let questions = state.questions.load();
+    let storylines = state.questions.load();
+    let questions = storylines.at(crate::server::storyline::current().await);
     // What the chain verifiably answered - the same lookup a
     // `requires_chain` gate does, so a forged or foreign hash resolves
     // to nothing - and therefore where it sent the visitor.
@@ -2583,6 +2585,7 @@ pub async fn suggest_page_edit(question_id: String, text: String) -> Result<(),
         SUGGESTION_ALTERNATIVE,
         &responses,
         now_ms,
+        0,
     )
     .await
     .map_err(|e| ServerFnError::new(e.to_string()))?;
@@ -2593,6 +2596,7 @@ pub async fn suggest_page_edit(question_id: String, text: String) -> Result<(),
         alternative: SUGGESTION_ALTERNATIVE.to_string(),
         responses: responses.clone(),
         timestamp_ms: now_ms,
+        storyline: 0,
     };
     if let Err(e) = emit_answer_submitted(&state.nats, &event).await {
         tracing::warn!(question_id, "the suggestion is on file but was not announced: {e}");
@@ -2679,7 +2683,8 @@ pub async fn submit_answer(
     // resolve_question, not a plain map get: a dynamic page's concrete
     // path (what the client holds as its question id) resolves to the
     // pattern page it came from.
-    let question = crate::content::resolve_question(&state.questions.load(), &question_id)
+    let storyline = crate::server::storyline::current().await;
+    let question = crate::content::resolve_question(state.questions.load().at(storyline), &question_id)
         .ok_or_else(|| ServerFnError::new("unknown question"))?;
 
     let session: tower_sessions::Session = leptos_axum::extract().await?;
@@ -2796,6 +2801,7 @@ pub async fn submit_answer(
             alternative: alternative.clone(),
             responses: responses.clone(),
             timestamp_ms,
+            storyline: storyline as u32,
         },
     )
     .await
@@ -2821,6 +2827,7 @@ pub async fn submit_answer(
             &alternative,
             &responses,
             timestamp_ms,
+            storyline as u32,
         )
         .await
         {
@@ -2829,7 +2836,7 @@ pub async fn submit_answer(
         // Arrival is a state too: what the schema says the first
         // state sends, it sends now.
         if let Some(initial) = state.aggregates.load().get(bucket).map(|s| s.initial.clone()) {
-            crate::mail::on_state(&state, bucket, &chain_hash, &initial, &responses).await;
+            crate::mail::on_state(&state, bucket, &chain_hash, &initial, &responses, storyline as u32).await;
             crate::people::on_state(&state, bucket, &chain_hash, &initial, &responses).await;
         }
     }

src/content/gitea.rs

@@ -9,20 +9,27 @@ use super::*;
 /// config; a file that exists but doesn't parse or validate is a real
 /// error, surfaced at boot rather than papered over.
 #[cfg(feature = "ssr")]
-pub async fn load_site_from_gitea(repo_url: &str, branch: &str) -> anyhow::Result<SiteConfig> {
+pub async fn load_site_from_gitea(repo_url: &str, branch: &str) -> anyhow::Result<Storylines<SiteConfig>> {
     let (owner, repo) = parse_owner_repo(repo_url)?;
     let api_base = gitea_api_base(repo_url)?;
     let raw = match fetch_gitea_file(&api_base, &owner, &repo, branch, "site.yaml").await {
         Ok(raw) => raw,
         Err(e) => {
             tracing::info!("no site.yaml in content repo ({e}), using default branding");
-            return Ok(SiteConfig::default());
+            return Ok(Storylines::one(SiteConfig::default()));
         }
     };
-    let site: SiteConfig =
-        serde_yaml::from_str(&raw).map_err(|e| anyhow::anyhow!("parsing site.yaml: {e}"))?;
-    site.validate()?;
-    Ok(site)
+    // The invite mail's words may be several (see `variants.rs`).
+    let files = vec![("site.yaml".to_string(), raw)];
+    let arity = super::variants::arity(&files)?;
+    let mut each = Vec::with_capacity(arity);
+    for n in 0..arity {
+        let site: SiteConfig =
+            serde_yaml::from_str(&super::variants::storyline(&files, n)[0].1).map_err(|e| anyhow::anyhow!("parsing site.yaml: {e}"))?;
+        site.validate()?;
+        each.push(site);
+    }
+    Ok(Storylines { each })
 }
 
 /// Extracts `scheme://host` from a repo's normal browser URL - the
@@ -107,11 +114,18 @@ pub(crate) async fn fetch_gitea_file(
 pub async fn load_aggregates_from_gitea(
     repo_url: &str,
     branch: &str,
-) -> anyhow::Result<std::collections::HashMap<String, crate::aggregates::AggregateSchema>> {
+) -> anyhow::Result<Storylines<std::collections::HashMap<String, crate::aggregates::AggregateSchema>>> {
     let (owner, repo) = parse_owner_repo(repo_url)?;
     let api_base = gitea_api_base(repo_url)?;
     let raw = fetch_gitea_file(&api_base, &owner, &repo, branch, "aggregates.yaml").await?;
-    crate::aggregates::parse_aggregates_yaml(&raw)
+    // A mail's subject and body may be several (see `variants.rs`);
+    // the runtime's own buckets are added to every storyline.
+    let files = vec![("aggregates.yaml".to_string(), raw)];
+    let arity = super::variants::arity(&files)?;
+    let each = (0..arity)
+        .map(|n| crate::aggregates::parse_aggregates_yaml(&super::variants::storyline(&files, n)[0].1).map(with_builtin_aggregates))
+        .collect::<anyhow::Result<Vec<_>>>()?;
+    Ok(Storylines { each })
 }
 
 #[cfg(feature = "ssr")]
@@ -119,7 +133,7 @@ pub async fn load_questions_from_gitea(
     repo_url: &str,
     branch: &str,
     subdir: &str,
-) -> anyhow::Result<std::collections::HashMap<String, Question>> {
+) -> anyhow::Result<Storylines<std::collections::HashMap<String, Question>>> {
     let (owner, repo) = parse_owner_repo(repo_url)?;
     let api_base = gitea_api_base(repo_url)?;
 
@@ -161,7 +175,20 @@ pub async fn load_questions_from_gitea(
             .map_err(|e| anyhow::anyhow!("fetching {path}: {e}"))?;
         files.push((path[prefix.len()..].to_string(), raw));
     }
-    build_questions(&files)
+    build_storylines(&files)
+}
+
+/// Every storyline's arity is the site's or one: a mail told in two
+/// voices on a site whose pages are told in three has a hole in it.
+#[cfg(feature = "ssr")]
+pub fn same_arity(questions: usize, aggregates: usize, site: usize) -> anyhow::Result<usize> {
+    let arity = questions.max(aggregates).max(site);
+    for (what, n) in [("questions", questions), ("aggregates.yaml", aggregates), ("site.yaml", site)] {
+        if n != 1 && n != arity {
+            anyhow::bail!("{what} tells {n} storyline(s), but the site tells {arity}; every list of texts has the same length");
+        }
+    }
+    Ok(arity)
 }
 
 /// Published by the content repo's own CI (after it lints a push) to
@@ -192,11 +219,11 @@ pub async fn watch_for_reload(
     repo_url: String,
     branch: String,
     subdir: String,
-    questions: std::sync::Arc<arc_swap::ArcSwap<std::collections::HashMap<String, Question>>>,
+    questions: std::sync::Arc<arc_swap::ArcSwap<Storylines<std::collections::HashMap<String, Question>>>>,
     aggregates: std::sync::Arc<
-        arc_swap::ArcSwap<std::collections::HashMap<String, crate::aggregates::AggregateSchema>>,
+        arc_swap::ArcSwap<Storylines<std::collections::HashMap<String, crate::aggregates::AggregateSchema>>>,
     >,
-    site: std::sync::Arc<arc_swap::ArcSwap<SiteConfig>>,
+    site: std::sync::Arc<arc_swap::ArcSwap<Storylines<SiteConfig>>>,
     access: std::sync::Arc<arc_swap::ArcSwap<crate::access::Policy>>,
 ) {
     let mut sub = match nats.subscribe(CONTENT_RELOAD_SUBJECT).await {
@@ -209,7 +236,7 @@ pub async fn watch_for_reload(
     use futures::StreamExt;
     while sub.next().await.is_some() {
         let loaded_aggregates = match load_aggregates_from_gitea(&repo_url, &branch).await {
-            Ok(loaded) => with_builtin_aggregates(loaded),
+            Ok(loaded) => loaded,
             Err(e) => {
                 tracing::error!(error = %e, "aggregates.yaml reload failed, keeping last-good content");
                 continue;
@@ -228,7 +255,7 @@ pub async fn watch_for_reload(
         };
         match load_questions_from_gitea(&repo_url, &branch, &subdir).await {
             Ok(loaded) => {
-                if let Err(e) = validate_questions(&loaded, &loaded_aggregates) {
+                if let Err(e) = validate_questions(&loaded, &loaded_aggregates).and_then(|_| same_arity(loaded.arity(), loaded_aggregates.arity(), loaded_site.arity())) {
                     tracing::error!(error = %e, "content reload failed validation, keeping last-good content");
                     continue;
                 }

src/content/mod.rs

@@ -13,12 +13,16 @@ use serde::{Deserialize, Serialize};
 // Loading is server-only; the rest is shared with the browser build.
 #[cfg(feature = "ssr")]
 mod gitea;
+#[cfg(feature = "ssr")]
+mod variants;
 mod handlers;
 mod markdown;
 mod validate;
 
 #[cfg(feature = "ssr")]
 pub use gitea::*;
+#[cfg(feature = "ssr")]
+pub use variants::*;
 pub use handlers::*;
 pub use markdown::*;
 pub use validate::*;
@@ -1073,6 +1077,25 @@ pub fn resolve_question(
 #[cfg(feature = "ssr")]
 pub fn build_questions(
     files: &[(String, String)],
+) -> anyhow::Result<std::collections::HashMap<String, Question>> {
+    // The first storyline, once every list of texts has been held to
+    // the site's arity (see `variants.rs`); the machinery reads this
+    // one, and `build_storylines` builds the rest for the visitors.
+    variants::arity(files)?;
+    build_one_storyline(&variants::storyline(files, 0))
+}
+
+/// Every storyline of the content, each a full map of questions.
+#[cfg(feature = "ssr")]
+pub fn build_storylines(files: &[(String, String)]) -> anyhow::Result<variants::Storylines<std::collections::HashMap<String, Question>>> {
+    let arity = variants::arity(files)?;
+    let each = (0..arity).map(|n| build_one_storyline(&variants::storyline(files, n))).collect::<anyhow::Result<Vec<_>>>()?;
+    Ok(variants::Storylines { each })
+}
+
+#[cfg(feature = "ssr")]
+fn build_one_storyline(
+    files: &[(String, String)],
 ) -> anyhow::Result<std::collections::HashMap<String, Question>> {
     // Sections first: (directory prefix, config), shallowest first so a
     // later (deeper) section overrides an outer one field-by-field.

src/content/validate.rs

@@ -278,9 +278,12 @@ pub fn validate_questions(
                         .flat_map(|f| &f.requirements)
                         .any(|r| r.name == name && !r.optional)
                 };
-                if !has("name") || !has("email") {
+                // A person is known by a phone number or an address;
+                // either will do, since memberships key on the number
+                // first and Kanidm on the address.
+                if !has("name") || !(has("email") || has("phone")) {
                     anyhow::bail!(
-                        "question {:?} alternative {:?}: an invite must collect required `name` and `email` fields",
+                        "question {:?} alternative {:?}: an invite must collect a required `name` and a required `email` or `phone` field",
                         question.id, alternative.name
                     );
                 }

src/content/variants.rs

@@ -0,0 +1,224 @@
+//! Storylines: a text may be several, and `[n]` runs through the site.
+//!
+//! Anywhere content says something to a person - a page's `name` and
+//! `description`, an alternative's, a feature's, a `label`, a
+//! `placeholder`, a mail's `subject` and `body`, a list's `empty` line,
+//! the `consequence` buttons and `encouragements` - it may give a list
+//! instead of one string:
+//!
+//! ```yaml
+//! description:
+//!   - Dugnad, 17. mai og komiteene trenger flere hender. Si hva du kan.
+//!   - Naboene gjør det meste selv. Her melder du deg til det du har lyst på.
+//! ```
+//!
+//! Every such list has the same length, the site's *arity*, and a
+//! visitor is given one index for the whole site (a cookie, see
+//! `main.rs`), so they read one storyline from the front door to the
+//! mail they get. A single string is every storyline. What a visitor
+//! did is recorded with the index (`AnswerSubmitted.variant`), so the
+//! storylines can be compared on what people actually did, and nothing
+//! else about them.
+//!
+//! This is done to the YAML before the structs see it: the files are
+//! expanded once per storyline, and everything downstream keeps its one
+//! string per field. Keys that name things to the machine - a field's
+//! `name`, a select's `options`, states, groups, paths - never vary.
+//!
+//! The lint holds every list to the arity, so a storyline cannot have
+//! a hole in it.
+
+use serde_yaml::Value;
+
+/// Keys whose value is one string to a person.
+const TEXT: &[&str] = &["name", "description", "label", "placeholder", "subject", "body", "empty", "title"];
+/// Keys whose value is a list of strings to a person; their storylines
+/// are a list of lists.
+const TEXT_LIST: &[&str] = &["consequence", "encouragements"];
+
+/// Where in a document a key is not text but an identifier: a
+/// requirement's `name` is the stored field, never varied.
+fn is_identifier(path: &[String], key: &str) -> bool {
+    // `path` ends with the key itself, then the item's index, then the
+    // list it is in.
+    key == "name" && path.iter().rev().nth(2).is_some_and(|p| p == "requirements")
+}
+
+fn is_strings(seq: &[Value]) -> bool {
+    !seq.is_empty() && seq.iter().all(|v| v.is_string())
+}
+
+fn is_lists_of_strings(seq: &[Value]) -> bool {
+    !seq.is_empty() && seq.iter().all(|v| v.as_sequence().is_some_and(|s| s.iter().all(|x| x.is_string())))
+}
+
+/// The storyline counts found in a document, with where each was.
+fn counts(value: &Value, path: &mut Vec<String>, out: &mut Vec<(String, usize)>) {
+    match value {
+        Value::Mapping(map) => {
+            for (k, v) in map {
+                let key = k.as_str().unwrap_or_default().to_string();
+                path.push(key.clone());
+                let variants = match v {
+                    Value::Sequence(seq) if TEXT.contains(&key.as_str()) && !is_identifier(path, &key) && is_strings(seq) => Some(seq.len()),
+                    Value::Sequence(seq) if TEXT_LIST.contains(&key.as_str()) && is_lists_of_strings(seq) => Some(seq.len()),
+                    _ => None,
+                };
+                match variants {
+                    Some(n) => out.push((path.join("."), n)),
+                    None => counts(v, path, out),
+                }
+                path.pop();
+            }
+        }
+        Value::Sequence(seq) => {
+            for (i, v) in seq.iter().enumerate() {
+                path.push(i.to_string());
+                counts(v, path, out);
+                path.pop();
+            }
+        }
+        _ => {}
+    }
+}
+
+/// One storyline of a document: every list of texts becomes its `n`th.
+fn pick(value: &mut Value, path: &mut Vec<String>, n: usize) {
+    match value {
+        Value::Mapping(map) => {
+            for (k, v) in map.iter_mut() {
+                let key = k.as_str().unwrap_or_default().to_string();
+                path.push(key.clone());
+                let chosen = match v {
+                    Value::Sequence(seq) if TEXT.contains(&key.as_str()) && !is_identifier(path, &key) && is_strings(seq) => Some(seq[n.min(seq.len() - 1)].clone()),
+                    Value::Sequence(seq) if TEXT_LIST.contains(&key.as_str()) && is_lists_of_strings(seq) => Some(seq[n.min(seq.len() - 1)].clone()),
+                    _ => None,
+                };
+                match chosen {
+                    Some(c) => *v = c,
+                    None => pick(v, path, n),
+                }
+                path.pop();
+            }
+        }
+        Value::Sequence(seq) => {
+            for (i, v) in seq.iter_mut().enumerate() {
+                path.push(i.to_string());
+                pick(v, path, n);
+                path.pop();
+            }
+        }
+        _ => {}
+    }
+}
+
+/// How many storylines these files tell: the length every list of
+/// texts has, or 1 when there is none. A list of another length is an
+/// error that names it.
+pub fn arity(files: &[(String, String)]) -> anyhow::Result<usize> {
+    let mut found: Vec<(String, String, usize)> = Vec::new();
+    for (rel, raw) in files {
+        let Ok(value) = serde_yaml::from_str::<Value>(raw) else { continue };
+        let mut out = Vec::new();
+        counts(&value, &mut Vec::new(), &mut out);
+        found.extend(out.into_iter().map(|(p, n)| (rel.clone(), p, n)));
+    }
+    let arity = found.iter().map(|(_, _, n)| *n).max().unwrap_or(1);
+    if let Some((rel, p, n)) = found.iter().find(|(_, _, n)| *n != arity) {
+        anyhow::bail!("{rel}: {p} tells {n} storyline(s), but the site tells {arity}; every list of texts has the same length");
+    }
+    Ok(arity.max(1))
+}
+
+/// The files as storyline `n` tells them.
+pub fn storyline(files: &[(String, String)], n: usize) -> Vec<(String, String)> {
+    files
+        .iter()
+        .map(|(rel, raw)| {
+            let Ok(mut value) = serde_yaml::from_str::<Value>(raw) else { return (rel.clone(), raw.clone()) };
+            let mut out = Vec::new();
+            counts(&value, &mut Vec::new(), &mut out);
+            if out.is_empty() {
+                return (rel.clone(), raw.clone());
+            }
+            pick(&mut value, &mut Vec::new(), n);
+            (rel.clone(), serde_yaml::to_string(&value).unwrap_or_else(|_| raw.clone()))
+        })
+        .collect()
+}
+
+/// One thing per storyline, and the first as what the machinery reads
+/// when nobody in particular is asking: a seed, a lint, a desk sweep.
+#[derive(Clone, Debug)]
+pub struct Storylines<T> {
+    pub each: Vec<T>,
+}
+
+impl<T> Storylines<T> {
+    pub fn one(item: T) -> Self {
+        Storylines { each: vec![item] }
+    }
+
+    pub fn arity(&self) -> usize {
+        self.each.len().max(1)
+    }
+
+    /// Storyline `n`, or the last for an index from a site that told
+    /// more storylines than this one does.
+    pub fn at(&self, n: usize) -> &T {
+        &self.each[n.min(self.each.len() - 1)]
+    }
+}
+
+impl<T> std::ops::Deref for Storylines<T> {
+    type Target = T;
+    fn deref(&self) -> &T {
+        &self.each[0]
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const PAGE: &str = "name: [Vil du hjelpe til?, Trenger naboene deg?]\ndescription: Alle trenger flere hender.\nalternatives:\n  - name: [Bli med, Meld deg]\n    description: [Si hva du kan., Si hva du har lyst på.]\n    consequence: [[Send], [Meld meg]]\n    features:\n      - name: Skjema\n        requirements:\n          - name: [navn]\n            label: [Navn, Hva heter du?]\n          - name: hva\n            type: select\n            options: [Dugnad, Komité]\n";
+
+    #[test]
+    fn every_list_of_texts_is_a_storyline_and_identifiers_are_not() {
+        let files = vec![("index.yaml".to_string(), PAGE.to_string())];
+        assert_eq!(arity(&files).unwrap(), 2);
+        let second = storyline(&files, 1);
+        let v: Value = serde_yaml::from_str(&second[0].1).unwrap();
+        assert_eq!(v["name"], "Trenger naboene deg?");
+        assert_eq!(v["description"], "Alle trenger flere hender.");
+        assert_eq!(v["alternatives"][0]["name"], "Meld deg");
+        assert_eq!(v["alternatives"][0]["consequence"], serde_yaml::to_value(vec!["Meld meg"]).unwrap());
+        // A requirement's name is the stored field: left as written.
+        assert_eq!(v["alternatives"][0]["features"][0]["requirements"][0]["name"], serde_yaml::to_value(vec!["navn"]).unwrap());
+        assert_eq!(v["alternatives"][0]["features"][0]["requirements"][0]["label"], "Hva heter du?");
+        // Options are values people choose from and are stored: untouched.
+        assert_eq!(v["alternatives"][0]["features"][0]["requirements"][1]["options"], serde_yaml::to_value(vec!["Dugnad", "Komité"]).unwrap());
+    }
+
+    #[test]
+    fn a_site_with_no_lists_tells_one_storyline_and_a_short_list_is_refused() {
+        let plain = vec![("index.yaml".to_string(), "name: Hva?\nalternatives:\n  - name: A\n    consequence: [Send]\n".to_string())];
+        assert_eq!(arity(&plain).unwrap(), 1);
+        assert_eq!(storyline(&plain, 0)[0].1, plain[0].1);
+        let uneven = vec![
+            ("index.yaml".to_string(), PAGE.to_string()),
+            ("b.yaml".to_string(), "name: [En, To, Tre]\n".to_string()),
+        ];
+        let err = arity(&uneven).unwrap_err().to_string();
+        assert!(err.contains("b.yaml: name tells 3") && err.contains("tells 2") || err.contains("tells 3"), "{err}");
+    }
+
+    #[test]
+    fn the_first_storyline_is_what_the_machinery_reads() {
+        let s = Storylines { each: vec!["a", "b"] };
+        assert_eq!(*s, "a");
+        assert_eq!(*s.at(1), "b");
+        assert_eq!(*s.at(7), "b");
+        assert_eq!(s.arity(), 2);
+    }
+}

src/deadlines.rs

@@ -94,7 +94,7 @@ pub async fn sweep(state: &AppState) -> anyhow::Result<()> {
             if let Ok(data) = serde_json::to_vec(&answer) {
                 let _ = store.put(&id, data.into()).await;
             }
-            crate::mail::on_state(state, &schema.bucket, &id, &target, &answer.responses).await;
+            crate::mail::on_state(state, &schema.bucket, &id, &target, &answer.responses, answer.storyline).await;
             crate::people::on_state(state, &schema.bucket, &id, &target, &answer.responses).await;
 
             let parent_hashes = vec![id.clone()];
@@ -108,6 +108,7 @@ pub async fn sweep(state: &AppState) -> anyhow::Result<()> {
                     alternative: target.clone(),
                     responses: payload,
                     timestamp_ms: now_ms,
+                    storyline: answer.storyline,
                 },
             )
             .await
@@ -145,6 +146,7 @@ aggregates:
             id: "r".into(), question_id: "/q".into(), alternative: "a".into(),
             responses: serde_json::json!({}), state: state.into(),
             submitted_ms: since_ms, decided_ms: None, decided_by: None, notes: vec![],
+            storyline: 0,
         }
     }
 

src/events/mod.rs

@@ -15,6 +15,10 @@ pub struct AnswerSubmitted {
     pub alternative: String,
     pub responses: serde_json::Value,
     pub timestamp_ms: i64,
+    /// The storyline the person read (see `content/variants.rs`): what
+    /// the storylines are compared on, and nothing else about them.
+    #[serde(default)]
+    pub storyline: u32,
 }
 
 pub const ANSWERS_SUBJECT: &str = "portal.answers.submitted";

src/lib.rs

@@ -35,6 +35,8 @@ pub mod mail;
 pub mod seed;
 #[cfg(feature = "ssr")]
 pub mod memberships;
+#[cfg(feature = "ssr")]
+pub mod report;
 
 pub mod maps;
 

src/mail.rs

@@ -306,8 +306,10 @@ async fn publish(js: &async_nats::jetstream::Context, mail: &Outgoing) -> anyhow
 /// if anything. Best-effort by design - the transition is already
 /// committed, and a mail that cannot be rendered is logged, never a
 /// failed request.
-pub async fn on_state(state: &crate::server::AppState, bucket: &str, id: &str, to_state: &str, responses: &serde_json::Value) {
-    let Some(spec) = state.aggregates.load().get(bucket).and_then(|s| s.mail_for(to_state)).cloned() else {
+pub async fn on_state(state: &crate::server::AppState, bucket: &str, id: &str, to_state: &str, responses: &serde_json::Value, storyline: u32) {
+    // The mail tells the storyline the person read.
+    let storyline = storyline as usize;
+    let Some(spec) = state.aggregates.load().at(storyline).get(bucket).and_then(|s| s.mail_for(to_state)).cloned() else {
         // A suggestion has its own words for this unless the content
         // gave the state a mail, which then is the one sent.
         if bucket == crate::content::EDIT_SUGGESTIONS_BUCKET {
@@ -315,7 +317,8 @@ pub async fn on_state(state: &crate::server::AppState, bucket: &str, id: &str, t
         }
         return;
     };
-    let site = state.site.load();
+    let site_storylines = state.site.load();
+    let site = site_storylines.at(storyline);
     let Some(cfg) = &site.mail else {
         tracing::warn!(bucket, to_state, "a mail is declared for this state, but site.yaml has no `mail.from` - not sent");
         return;
@@ -702,6 +705,7 @@ mod tests {
             responses: serde_json::json!({ "email": email, "where": "The bend" }),
             state: "open".into(),
             submitted_ms: 1,
+            storyline: 0,
             decided_ms: None,
             decided_by: None,
             notes: Vec::new(),

src/main.rs

@@ -30,13 +30,12 @@ async fn main() -> anyhow::Result<()> {
     let content_branch = std::env::var("CONTENT_BRANCH").unwrap_or_else(|_| "main".to_string());
     let gitea_base = content::gitea_api_base(&content_repo)?;
     let content_raw_base = content::gitea_raw_base(&content_repo)?;
-    let aggregates = content::with_builtin_aggregates(
-        content::load_aggregates_from_gitea(&content_repo, &content_branch).await?,
-    );
+    let aggregates = content::load_aggregates_from_gitea(&content_repo, &content_branch).await?;
     let questions = content::load_questions_from_gitea(&content_repo, &content_branch, "questions").await?;
     content::validate_questions(&questions, &aggregates)?;
     let site = content::load_site_from_gitea(&content_repo, &content_branch).await?;
-    tracing::info!(count = questions.len(), repo = %content_repo, branch = %content_branch, "loaded content");
+    let storylines = content::same_arity(questions.arity(), aggregates.arity(), site.arity())?;
+    tracing::info!(count = questions.len(), storylines, repo = %content_repo, branch = %content_branch, "loaded content");
     let access = Arc::new(arc_swap::ArcSwap::from_pointee(portal::access::Policy::from_content(&questions, &aggregates)));
     let questions = Arc::new(arc_swap::ArcSwap::from_pointee(questions));
     let aggregates = Arc::new(arc_swap::ArcSwap::from_pointee(aggregates));
@@ -225,6 +224,8 @@ async fn main() -> anyhow::Result<()> {
             get(upload::attachment),
         )
         .route("/gitea-repo", get(content::gitea_repo_handler))
+        // What the storylines did, as counts (report.rs).
+        .route("/report", get(portal::report::handler))
         // Content-shipped assets (hero module etc.), same-origin.
         .route("/site/{*path}", get(content::site_asset_handler))
         .route("/automation/kv/{bucket}", get(content::automation_kv_handler))
@@ -273,7 +274,9 @@ async fn main() -> anyhow::Result<()> {
             },
         )
         .fallback(leptos_axum::file_and_error_handler::<AppState, _>(shell))
-        .layer(session_layer);
+        .layer(session_layer)
+        // Which storyline this visitor reads, before anything renders.
+        .layer(axum::middleware::from_fn_with_state(state.clone(), portal::server::storyline::assign));
     // Outermost, so a caller who is over the limit is turned away
     // before a session is loaded or a handler is entered.
     let app = match governor {

src/memberships.rs

@@ -226,6 +226,7 @@ async fn move_to(state: &crate::server::AppState, store: &async_nats::jetstream:
         alternative: target.to_string(),
         responses: payload,
         timestamp_ms: now_ms,
+        storyline: answer.storyline,
     };
     let _ = crate::events::emit_answer_submitted(&state.nats, &event).await;
     Ok(answer)
@@ -266,7 +267,7 @@ pub async fn grant(state: &crate::server::AppState, group: &str, name: &str, who
                 "name": name, "group": group, "by": by,
                 "phone": who.phone, "email": who.email, "sub": who.sub,
             });
-            crate::answers::store_answer(&state.jetstream, &state.aggregates.load(), BUCKET, id, "/", "Membership", &responses, now_ms).await?;
+            crate::answers::store_answer(&state.jetstream, &state.aggregates.load(), BUCKET, id, "/", "Membership", &responses, now_ms, 0).await?;
             Ok(invited(true))
         }
     }
@@ -346,6 +347,7 @@ mod tests {
             responses: serde_json::json!({ "group": group, "phone": phone, "email": email, "sub": sub, "name": "X" }),
             state: state.into(),
             submitted_ms: 0,
+            storyline: 0,
             decided_ms: None,
             decided_by: None,
             notes: Vec::new(),

src/people.rs

@@ -414,7 +414,7 @@ pub async fn record(state: &crate::server::AppState, invited: &Invited, responsi
         responses["responsible_for"] = serde_json::json!(responsible_for);
     }
     let id = crate::chain::hash_node("/", &[], &responses, now_ms);
-    if let Err(e) = crate::answers::store_answer(&state.jetstream, &state.aggregates.load(), INVITES_BUCKET, id, "/", SEED_ALTERNATIVE, &responses, now_ms).await {
+    if let Err(e) = crate::answers::store_answer(&state.jetstream, &state.aggregates.load(), INVITES_BUCKET, id, "/", SEED_ALTERNATIVE, &responses, now_ms, 0).await {
         tracing::warn!(user = %invited.username, "the invite is sent, but could not be put on file for a desk: {e}");
     }
 }
@@ -454,6 +454,7 @@ async fn move_invite(state: &crate::server::AppState, store: &async_nats::jetstr
         alternative: target.to_string(),
         responses: payload,
         timestamp_ms: now_ms,
+        storyline: answer.storyline,
     };
     if let Err(e) = crate::events::emit_answer_submitted(&state.nats, &event).await {
         tracing::warn!(id = %answer.id, target, "the invite was moved but not published: {e}");
@@ -702,6 +703,7 @@ mod tests {
             }}),
             state: state.into(),
             submitted_ms: 1_000,
+            storyline: 0,
             decided_ms: None,
             decided_by: None,
             notes: Vec::new(),

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)
+}

src/resource.rs

@@ -33,7 +33,7 @@ pub async fn get_resource(
     use crate::server::AppState;
 
     let state = expect_context::<AppState>();
-    let feature = find_feature(&state, &question_id, &alternative, &feature_name)?;
+    let feature = find_feature(&state, crate::server::storyline::current().await, &question_id, &alternative, &feature_name)?;
     let resource = feature
         .resource
         .as_ref()
@@ -62,7 +62,7 @@ pub async fn get_requirement_options(
     use crate::server::AppState;
 
     let state = expect_context::<AppState>();
-    let feature = find_feature(&state, &question_id, &alternative, &feature_name)?;
+    let feature = find_feature(&state, crate::server::storyline::current().await, &question_id, &alternative, &feature_name)?;
     let requirement = feature
         .requirements
         .iter()
@@ -103,7 +103,7 @@ pub async fn get_requirement_binding(
     use crate::server::AppState;
 
     let state = expect_context::<AppState>();
-    let feature = find_feature(&state, &question_id, &alternative, &feature_name)?;
+    let feature = find_feature(&state, crate::server::storyline::current().await, &question_id, &alternative, &feature_name)?;
     let requirement = feature
         .requirements
         .iter()
@@ -128,6 +128,7 @@ pub async fn get_requirement_binding(
 #[cfg(feature = "ssr")]
 fn find_feature(
     state: &crate::server::AppState,
+    storyline: usize,
     question_id: &str,
     alternative: &str,
     feature_name: &str,
@@ -137,7 +138,7 @@ fn find_feature(
     // also what substitutes the URL segment into the page's resource
     // keys - so this lookup is where a `/review/<record>` page's
     // feature acquires its record-specific key.
-    let question = crate::content::resolve_question(&state.questions.load(), question_id)
+    let question = crate::content::resolve_question(state.questions.load().at(storyline), question_id)
         .ok_or_else(|| ServerFnError::new("unknown question"))?;
     question
         .alternatives

src/server/mod.rs

@@ -1,6 +1,7 @@
 #![cfg(feature = "ssr")]
 
 pub mod oidc;
+pub mod storyline;
 
 use arc_swap::ArcSwap;
 use axum::extract::FromRef;
@@ -21,18 +22,18 @@ pub struct AppState {
     /// message (see `content::watch_for_reload`) - readers never hold
     /// a lock, just an atomic pointer load, so a reload never blocks or
     /// is blocked by an in-flight request.
-    pub questions: Arc<ArcSwap<HashMap<String, Question>>>,
+    pub questions: Arc<ArcSwap<crate::content::Storylines<HashMap<String, Question>>>>,
     /// Every bucket's event-sourced state graph, loaded from
     /// `aggregates.yaml` (see `content::load_aggregates_from_gitea`) and
     /// hot-swapped alongside `questions` on the same reload. A bucket
     /// with no entry here isn't event-sourced - plain KV mutate-in-place
     /// still works (see `answers.rs`).
-    pub aggregates: Arc<ArcSwap<HashMap<String, crate::aggregates::AggregateSchema>>>,
+    pub aggregates: Arc<ArcSwap<crate::content::Storylines<HashMap<String, crate::aggregates::AggregateSchema>>>>,
     /// Site branding from the content repo's optional `site.yaml`
     /// (title, wordmark, hero kind) - hot-swapped with `questions`/
     /// `aggregates` on the same reload. Default = the historical uhhm
     /// look.
-    pub site: Arc<ArcSwap<crate::content::SiteConfig>>,
+    pub site: Arc<ArcSwap<crate::content::Storylines<crate::content::SiteConfig>>>,
     /// The access policy compiled from the content above (see
     /// `access.rs`), swapped with it on every reload. Every server entry
     /// point decides through this and nothing else.

src/server/storyline.rs

@@ -0,0 +1,70 @@
+//! Which storyline a visitor reads (see `content/variants.rs`): one
+//! index for the whole site, chosen at their first request and kept in
+//! a cookie for a year, so every page and every mail they get tells
+//! the same story. A site that tells one story sets no cookie.
+#![cfg(feature = "ssr")]
+
+use axum::{
+    extract::{Request, State},
+    http::header::{COOKIE, SET_COOKIE},
+    middleware::Next,
+    response::Response,
+};
+
+pub const COOKIE_NAME: &str = "portal_storyline";
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct Storyline(pub usize);
+
+/// The index in a request's cookies, if it names one this site tells.
+fn from_cookies(header: Option<&str>, arity: usize) -> Option<usize> {
+    header?
+        .split(';')
+        .map(str::trim)
+        .find_map(|kv| kv.strip_prefix(COOKIE_NAME).and_then(|rest| rest.strip_prefix('=')))
+        .and_then(|v| v.trim().parse::<usize>().ok())
+        .filter(|n| *n < arity)
+}
+
+/// Evenly, from nothing about the person.
+fn pick(arity: usize) -> usize {
+    (uuid::Uuid::new_v4().as_u128() % arity.max(1) as u128) as usize
+}
+
+pub async fn assign(State(state): State<super::AppState>, mut req: Request, next: Next) -> Response {
+    let arity = state.questions.load().arity();
+    let held = from_cookies(req.headers().get(COOKIE).and_then(|v| v.to_str().ok()), arity);
+    let n = held.unwrap_or_else(|| pick(arity));
+    req.extensions_mut().insert(Storyline(n));
+    let mut res = next.run(req).await;
+    if held.is_none() && arity > 1 {
+        if let Ok(value) = format!("{COOKIE_NAME}={n}; Path=/; Max-Age=31536000; SameSite=Lax").parse() {
+            res.headers_mut().append(SET_COOKIE, value);
+        }
+    }
+    res
+}
+
+/// The storyline of the request a server function is answering, or
+/// the first when there is none to ask (a call outside a request).
+pub async fn current() -> usize {
+    leptos_axum::extract::<axum::Extension<Storyline>>()
+        .await
+        .map(|axum::Extension(Storyline(n))| n)
+        .unwrap_or(0)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn a_cookie_names_a_storyline_the_site_tells() {
+        assert_eq!(from_cookies(Some("a=b; portal_storyline=1; c=d"), 3), Some(1));
+        assert_eq!(from_cookies(Some("portal_storyline=7"), 3), None);
+        assert_eq!(from_cookies(Some("portal_storylines=1"), 3), None);
+        assert_eq!(from_cookies(None, 3), None);
+        assert!(pick(1) == 0);
+        assert!((0..50).all(|_| pick(3) < 3));
+    }
+}

tests/jetstream.rs

@@ -34,7 +34,7 @@ async fn a_submission_is_created_moved_refused_and_read_back_through_the_real_en
     let now = chrono::Utc::now().timestamp_millis();
 
     // The submission: a KV record in the initial state, plus the first event.
-    store_answer(&js, &schemas, &bucket, "rec-1".into(), "/", "Hire us", &json!({"email": "a@b.example"}), now)
+    store_answer(&js, &schemas, &bucket, "rec-1".into(), "/", "Hire us", &json!({"email": "a@b.example"}), now, 0)
         .await
         .expect("store");
     let store = js.get_key_value(&bucket).await.expect("bucket exists");
@@ -178,9 +178,9 @@ async fn a_membership_is_invited_becomes_active_at_sign_in_and_can_be_taken_back
         leptos_options: leptos::config::LeptosOptions::builder().output_name("test").build(),
         nats,
         jetstream: js,
-        questions: std::sync::Arc::new(arc_swap::ArcSwap::from_pointee(questions)),
-        aggregates: std::sync::Arc::new(arc_swap::ArcSwap::from_pointee(aggregates)),
-        site: std::sync::Arc::new(arc_swap::ArcSwap::from_pointee(Default::default())),
+        questions: std::sync::Arc::new(arc_swap::ArcSwap::from_pointee(portal::content::Storylines::one(questions))),
+        aggregates: std::sync::Arc::new(arc_swap::ArcSwap::from_pointee(portal::content::Storylines::one(aggregates))),
+        site: std::sync::Arc::new(arc_swap::ArcSwap::from_pointee(portal::content::Storylines::one(Default::default()))),
         access: std::sync::Arc::new(arc_swap::ArcSwap::from_pointee(access)),
         gitea_base: String::new(),
         content_raw_base: String::new(),