feat: personal library — filter by read/saved books, add save button

ui/src/lib/server/pocketbase.ts

@@ -346,6 +346,82 @@ export async function mergeSessionProgress(sessionId: string, userId: string): P
 	log.info('pocketbase', 'mergeSessionProgress: done', { sessionId, userId, count: sessionRows.length });
 }
 
+// ─── User library (saved books) ───────────────────────────────────────────────
+
+export interface UserLibraryEntry {
+	id?: string;
+	session_id: string;
+	user_id?: string;
+	slug: string;
+	saved_at: string;
+}
+
+function libraryFilter(sessionId: string, userId?: string): string {
+	if (userId) return `user_id="${userId}"`;
+	return `session_id="${sessionId}"`;
+}
+
+/** Returns all slugs the user has explicitly saved to their library. */
+export async function getSavedSlugs(sessionId: string, userId?: string): Promise<Set<string>> {
+	const rows = await listAll<UserLibraryEntry>(
+		'user_library',
+		libraryFilter(sessionId, userId)
+	);
+	return new Set(rows.map((r) => r.slug));
+}
+
+/** Returns whether a specific slug is saved. */
+export async function isBookSaved(
+	sessionId: string,
+	slug: string,
+	userId?: string
+): Promise<boolean> {
+	const filter = userId
+		? `user_id="${userId}"&&slug="${slug}"`
+		: `session_id="${sessionId}"&&slug="${slug}"`;
+	const row = await listOne<UserLibraryEntry>('user_library', filter);
+	return row !== null;
+}
+
+/** Save a book to the user's library. No-op if already saved. */
+export async function saveBook(
+	sessionId: string,
+	slug: string,
+	userId?: string
+): Promise<void> {
+	const alreadySaved = await isBookSaved(sessionId, slug, userId);
+	if (alreadySaved) return;
+	const payload: Partial<UserLibraryEntry> = {
+		session_id: sessionId,
+		slug,
+		saved_at: new Date().toISOString()
+	};
+	if (userId) payload.user_id = userId;
+	const res = await pbPost('/api/collections/user_library/records', payload);
+	if (!res.ok) {
+		const body = await res.text().catch(() => '');
+		log.error('pocketbase', 'saveBook POST failed', { slug, status: res.status, body });
+	}
+}
+
+/** Remove a book from the user's library. */
+export async function unsaveBook(
+	sessionId: string,
+	slug: string,
+	userId?: string
+): Promise<void> {
+	const filter = userId
+		? `user_id="${userId}"&&slug="${slug}"`
+		: `session_id="${sessionId}"&&slug="${slug}"`;
+	const row = await listOne<UserLibraryEntry & { id: string }>('user_library', filter);
+	if (!row) return;
+	const token = await getToken();
+	await fetch(`${PB_URL}/api/collections/user_library/records/${row.id}`, {
+		method: 'DELETE',
+		headers: { Authorization: `Bearer ${token}` }
+	});
+}
+
 // ─── Users ────────────────────────────────────────────────────────────────────
 
 import { scryptSync, randomBytes, timingSafeEqual } from 'node:crypto';