extrcation notes utility for parsing note links

src/lib/server/note-links.ts

@@ -0,0 +1,48 @@
+import type { Db } from './db/index.js';
+import { noteLinks, notes } from './db/schema.js';
+import { eq, inArray } from 'drizzle-orm';
+import { canAccessNote } from './api-utils.js';
+
+/**
+ * Sync link rows for a note: removes old associations, inserts the current set.
+ * Mirrors syncNoteTags — called right after a note's content is saved.
+ */
+export function syncNoteLinks(db: Db, noteId: string, targetIds: string[]): void {
+	db.delete(noteLinks).where(eq(noteLinks.sourceNoteId, noteId)).run();
+
+	for (const targetId of targetIds) {
+		db.insert(noteLinks).values({ sourceNoteId: noteId, targetNoteId: targetId }).run();
+	}
+}
+
+/**
+ * Find notes that link to the given note, scoped to what the requesting user
+ * can access — this both respects normal sharing boundaries and, as a side
+ * effect, prevents an unrelated note from appearing in someone's backlinks
+ * just because it happens to reference a note ID it was never shared to see.
+ */
+export function fetchBacklinksForNote(
+	db: Db,
+	noteId: string,
+	userId: number
+): { id: string; title: string }[] {
+	const linkRows = db
+		.select({ sourceNoteId: noteLinks.sourceNoteId })
+		.from(noteLinks)
+		.where(eq(noteLinks.targetNoteId, noteId))
+		.all();
+
+	if (linkRows.length === 0) return [];
+
+	const sourceIds = linkRows.map((r) => r.sourceNoteId);
+	const accessibleIds = sourceIds.filter((id) => canAccessNote(db, id, userId).canAccess);
+	if (accessibleIds.length === 0) return [];
+
+	const sourceNotes = db
+		.select({ id: notes.id, title: notes.title })
+		.from(notes)
+		.where(inArray(notes.id, accessibleIds))
+		.all();
+
+	return sourceNotes;
+}