v3: added content slugs, fixed real-time updates in client, added @mentions across the app, added new file selector and drop zone

api/services/notification-service.ts

@@ -7,6 +7,9 @@ import { APIErrorCode, APIException } from "../model/interfaces.ts";
 import { db, isNotificationRow, notificationRowToApi } from "../model/db.ts";
 import { sendToUser } from "./ws-service.ts";
 
+// Regex: matches @username not already inside a markdown link ([...] or (...)
+const MENTION_RE = /(?<![[(\\w])@([\w]+)/g;
+
 // ── Core CRUD ─────────────────────────────────────────────────────────────────
 
 // sourceKey: if set, INSERT OR IGNORE — same (user_id, source_key) pair is a no-op.
@@ -191,6 +194,45 @@ export function notifyDumpOwnerUpvote(
   );
 }
 
+export function notifyMentions(
+  mentionerUserId: string,
+  body: string,
+  contextType: "comment" | "dump" | "playlist",
+  contextId: string,
+  contextTitle: string,
+  dumpId?: string,
+): void {
+  const mentionerRow = db.prepare(
+    `SELECT username FROM users WHERE id = ?;`,
+  ).get(mentionerUserId) as { username: string } | undefined;
+  if (!mentionerRow) return;
+
+  const usernames = [...new Set(
+    [...body.matchAll(MENTION_RE)].map((m) => m[1].toLowerCase()),
+  )];
+
+  for (const username of usernames) {
+    const mentionedRow = db.prepare(
+      `SELECT id FROM users WHERE lower(username) = ?;`,
+    ).get(username) as { id: string } | undefined;
+    if (!mentionedRow || mentionedRow.id === mentionerUserId) continue;
+
+    createNotification(
+      mentionedRow.id,
+      "user_mentioned",
+      {
+        mentionerId: mentionerUserId,
+        mentionerUsername: mentionerRow.username,
+        contextType,
+        contextId,
+        contextTitle,
+        dumpId,
+      },
+      `mention:${contextType}:${contextId}:${mentionedRow.id}`,
+    );
+  }
+}
+
 export function notifyPlaylistFollowersNewDump(
   playlistId: string,
   playlistTitle: string,