Implement direct sign-up to an event with registration derived from meeting point memberships

backend/services/registration.service.js

@@ -35,17 +35,16 @@ const firstStringOf = value =>
     .find(v => typeof v === 'string' && v.trim().length > 0);
 
 /**
- * What a Join/Leave targets: the stored object must be a meeting point — an `as:Event` (checked by
- * `verifiedDelivery`, and by `meetingPointOf` on the creator's copy) anchored to an event by
- * `as:context` — whose creator is its `dc:creator`, required to own the pod the meeting point lies
- * in. Only on the copy the creator's pod serves (`meetingPointOf`) is that creator believed (the pod
+ * What a Join/Leave targets: the stored object must be an `as:Event` (checked by `verifiedDelivery`,
+ * and by `meetingPointOf` on the creator's copy) — a meeting point when anchored to an event by
+ * `as:context`, otherwise an event signed up to directly, which is its own anchor — whose creator is
+ * its `dc:creator`, required to own the pod it lies in. Only on the copy the creator's pod serves (`meetingPointOf`) is that creator believed (the pod
  * stamps the creator, and nobody can store a resource in someone else's pod); on the copy read
  * through the participant's pod, it only names where to read that one. Resolves
  * `{ ok, eventUri, creatorUri }` or a refusal.
  */
 function meetingPointTarget(meetingPoint, meetingPointUri) {
-  const eventUri = linkOf(meetingPoint, 'context', 'as:context', `${AS}context`);
-  if (!eventUri) return { ok: false, reason: `the meeting point ${meetingPointUri} names no single as:context (its event)` };
+  const eventUri = linkOf(meetingPoint, 'context', 'as:context', `${AS}context`) ?? meetingPointUri;
   const creatorUri = linkOf(meetingPoint, 'dc:creator', DC_CREATOR);
   if (!creatorUri) return { ok: false, reason: `the meeting point ${meetingPointUri} names no single dc:creator` };
   if (!isInActorPod(meetingPointUri, creatorUri)) {
@@ -55,9 +54,9 @@ function meetingPointTarget(meetingPoint, meetingPointUri) {
 }
 
 /**
- * The notification template for the creator of a meeting point (`pod-notifications.send`, rendered in
- * the creator's language): always ANONYMOUS, the meeting point named through `meetingPointName`, the
- * link to its event's meeting points (`eventUri`). Every value travels as a template PARAMETER, never
+ * The notification template for the creator of a target (`pod-notifications.send`, rendered in the
+ * creator's language): always ANONYMOUS, the target named through `meetingPointName` or `eventName`, the link to the
+ * event (`eventUri`), or to its meeting points when the target is one. Every value travels as a template PARAMETER, never
  * inside the template, so no user text is compiled.
  *
  * Never names the participant: naming would need a trustworthy signal that the creator is one of the
@@ -66,21 +65,18 @@ function meetingPointTarget(meetingPoint, meetingPointUri) {
  * request checked; platform defect reported upstream). Until that list can be trusted, every
  * notification is anonymous.
  */
-function notificationTemplate(change) {
-  const title =
-    change === 'join'
-      ? {
-          en: 'A participant joined your meeting point "{{{meetingPointName}}}"',
-          fr: 'Un participant a rejoint votre point de rencontre « {{{meetingPointName}}} »'
-        }
-      : {
-          en: 'A participant left your meeting point "{{{meetingPointName}}}"',
-          fr: 'Un participant a quitté votre point de rencontre « {{{meetingPointName}}} »'
-        };
-  return {
-    title,
-    actions: [{ caption: { en: 'View', fr: 'Voir' }, link: '/events/{{encodeUri eventUri}}/meeting-points' }]
+function notificationTemplate(change, isMeetingPoint) {
+  const joined = change === 'join';
+  const nameParam = isMeetingPoint ? 'meetingPointName' : 'eventName';
+  const subject = isMeetingPoint
+    ? { en: 'your meeting point', fr: 'votre point de rencontre' }
+    : { en: 'your event', fr: 'votre événement' };
+  const title = {
+    en: `A participant ${joined ? 'joined' : 'left'} ${subject.en} "{{{${nameParam}}}}"`,
+    fr: `Un participant a ${joined ? 'rejoint' : 'quitté'} ${subject.fr} « {{{${nameParam}}}} »`
   };
+  const link = isMeetingPoint ? '/events/{{encodeUri eventUri}}/meeting-points' : '/events/{{encodeUri eventUri}}';
+  return { title, actions: [{ caption: { en: 'View', fr: 'Voir' }, link }] };
 }
 
 // Participation (decision_2026-10-29_participation-privacy-mechanism; its delivery:
@@ -366,25 +362,27 @@ module.exports = {
       await expectItem(ctx, { collectionUri, itemUri: meetingPointUri, actorUri: participantUri, present: joining });
     },
     /**
-     * Tells the creator of the meeting point that a participant joined or left it — ALWAYS anonymously.
+     * Tells the creator of the target (a meeting point, or an event signed up to directly) that a
+     * participant joined or left it — ALWAYS anonymously.
      * The participant is never named: the only membership signal the app can read (the participant's
      * `apods:contacts` list) is forgeable, so naming cannot be trusted (platform defect reported
      * upstream, see `notificationTemplate`). The notification carries no `activity`: given one,
      * `pod-notifications.send` fetches the emitter's profile. A creator acting on their own meeting
-     * point is not notified. A failure is logged, never thrown: the act stands.
+     * point or event is not notified. A failure is logged, never thrown: the act stands.
      */
     async notifyCreator(ctx, { change, meetingPointUri, meetingPoint, eventUri, creatorUri, participantUri }) {
+      const isMeetingPoint = eventUri !== meetingPointUri;
       try {
         if (creatorUri === participantUri) {
-          this.logger.info(`${participantUri} acted on their own meeting point ${meetingPointUri}: no notification`);
+          this.logger.info(`${participantUri} acted on their own ${meetingPointUri}: no notification`);
           return;
         }
         this.logger.info(`Notifying ${creatorUri} of a ${change} on ${meetingPointUri}, anonymously`);
         await ctx.call('pod-notifications.send', {
-          template: notificationTemplate(change),
+          template: notificationTemplate(change, isMeetingPoint),
           recipientUri: creatorUri,
           context: meetingPointUri,
-          meetingPointName: firstStringOf(meetingPoint.name ?? meetingPoint['as:name'] ?? meetingPoint[`${AS}name`]) ?? '',
+          [isMeetingPoint ? 'meetingPointName' : 'eventName']: firstStringOf(meetingPoint.name ?? meetingPoint['as:name'] ?? meetingPoint[`${AS}name`]) ?? '',
           eventUri
         });
       } catch (e) {