Add NIP-50 thread search helper

src/lib/search.ts

@@ -0,0 +1,71 @@
+import type { Event } from "@nostr/tools/core";
+import type { Filter } from "@nostr/tools/filter";
+import { queryForum } from "$lib/relay";
+import { GROUP_ID, MODE } from "$lib/config";
+import { groupsStore } from "$lib/groups.svelte";
+
+export type SearchResult = {
+  threadId: string;
+  title: string;
+  snippet: string;
+  matchKind: "thread" | "reply";
+  createdAt: number;
+};
+
+function snippetOf(content: string): string {
+  const flat = content.replace(/\s+/g, " ").trim();
+  return flat.length > 140 ? flat.slice(0, 140) + "…" : flat;
+}
+
+// NIP-50 search over the forum relay: thread OPs (kind 11) and replies
+// (kind 1111), deduped by thread. Simple mode scopes to the single group;
+// full mode spans every visible room.
+export async function searchThreads(query: string): Promise<SearchResult[]> {
+  const filter: Filter = { kinds: [11, 1111], search: query, limit: 30 };
+  if (MODE === "simple") filter["#h"] = [GROUP_ID];
+  else if (groupsStore.list.length > 0)
+    filter["#h"] = groupsStore.list.map((g) => g.id);
+
+  const events = await queryForum(filter, { label: "search" });
+
+  const byThread = new Map<string, SearchResult>();
+  const opless: SearchResult[] = [];
+  for (const e of events) {
+    if (e.kind === 11) {
+      const existing = byThread.get(e.id);
+      // An OP match wins over a reply match on the same thread
+      if (existing && existing.matchKind === "thread") continue;
+      byThread.set(e.id, {
+        threadId: e.id,
+        title: e.tags.find((t) => t[0] === "title")?.[1] ?? "(untitled)",
+        snippet: snippetOf(e.content),
+        matchKind: "thread",
+        createdAt: e.created_at,
+      });
+    } else {
+      const root = e.tags.find((t) => t[0] === "E")?.[1];
+      if (!root || byThread.has(root)) continue;
+      const r: SearchResult = {
+        threadId: root,
+        title: "",
+        snippet: snippetOf(e.content),
+        matchKind: "reply",
+        createdAt: e.created_at,
+      };
+      byThread.set(root, r);
+      opless.push(r);
+    }
+  }
+
+  // Backfill titles for reply-only matches; the group relay truncates
+  // multi-id queries, so fetch each OP on its own
+  await Promise.all(
+    opless.map(async (r) => {
+      const ops = await queryForum({ kinds: [11], ids: [r.threadId] });
+      const op: Event | undefined = ops[0];
+      r.title = op?.tags.find((t) => t[0] === "title")?.[1] ?? "(untitled)";
+    }),
+  );
+
+  return [...byThread.values()].sort((a, b) => b.createdAt - a.createdAt);
+}