Split up space information and directory

src/app/recent.ts

@@ -0,0 +1,67 @@
+import {derived} from "svelte/store"
+import {groupBy, first, sortBy, uniqBy, ago, MONTH} from "@welshman/lib"
+import {MESSAGE, COMMENT, getTagValue, getTagValues, getIdAndAddress} from "@welshman/util"
+import type {TrustedEvent} from "@welshman/util"
+import {repository} from "@welshman/app"
+import {deriveEventsForUrl} from "@app/repository"
+import {CONTENT_KINDS} from "@app/content"
+
+export type RecentActivityItem = {
+  type: "message" | "content"
+  event: TrustedEvent
+  count: number
+  timestamp: number
+}
+
+// Recent activity for a space: latest message per room plus content with the
+// most recent activity (post or comment), sorted newest first.
+export const deriveRecentActivity = (url: string) => {
+  const since = ago(3, MONTH)
+  const messages = deriveEventsForUrl(url, [{kinds: [MESSAGE], since}])
+  const content = deriveEventsForUrl(url, [{kinds: CONTENT_KINDS, since}])
+  const comments = deriveEventsForUrl(url, [{kinds: [COMMENT], since}])
+
+  return derived([messages, content, comments], ([$messages, $content, $comments]) => {
+    const activity: RecentActivityItem[] = []
+
+    const byRoom = groupBy(e => getTagValue("h", e.tags), $messages)
+    for (const roomMessages of byRoom.values()) {
+      const latest = first(roomMessages)
+      if (latest) {
+        activity.push({
+          type: "message",
+          event: latest,
+          count: roomMessages.length,
+          timestamp: latest.created_at,
+        })
+      }
+    }
+
+    const latestActivityByKey = new Map<string, number>()
+
+    for (const event of $content) {
+      for (const k of getIdAndAddress(event)) {
+        latestActivityByKey.set(k, Math.max(latestActivityByKey.get(k) || 0, event.created_at))
+      }
+    }
+
+    for (const event of $comments) {
+      for (const k of getTagValues(["E", "A"], event.tags)) {
+        latestActivityByKey.set(k, Math.max(latestActivityByKey.get(k) || 0, event.created_at))
+      }
+    }
+
+    for (const [address, timestamp] of latestActivityByKey.entries()) {
+      const event = repository.getEvent(address)
+
+      if (event) {
+        activity.push({type: "content", event, timestamp, count: 1})
+      }
+    }
+
+    return sortBy(
+      a => -a.timestamp,
+      uniqBy(a => a.event.id, activity),
+    )
+  })
+}