1 files changed, 82 insertions, 0 deletions
diff --git a/src/client/db/study-builder.ts b/src/client/db/study-builder.ts
new file mode 100644
index 0000000..25d1652
--- /dev/null
+++ b/src/client/db/study-builder.ts
@@ -0,0 +1,82 @@
+import type { CardStateType } from "./index";
+import {
+	localCardRepository,
+	localNoteFieldTypeRepository,
+	localNoteFieldValueRepository,
+	localNoteRepository,
+	localNoteTypeRepository,
+} from "./repositories";
+
+export interface StudyCardView {
+	id: string;
+	deckId: string;
+	noteId: string;
+	isReversed: boolean;
+	state: CardStateType;
+	noteType: {
+		frontTemplate: string;
+		backTemplate: string;
+	};
+	fieldValuesMap: Record<string, string>;
+}
+
+/**
+ * Build study card views for all due cards in a deck from IndexedDB.
+ *
+ * Cards whose note or note type has been soft-deleted are skipped, mirroring
+ * the server-side enrichment in `enrichCardsForStudy`.
+ */
+export async function buildStudyCards(
+	deckId: string,
+): Promise<StudyCardView[]> {
+	const dueCards = await localCardRepository.findDueCards(deckId);
+	if (dueCards.length === 0) {
+		return [];
+	}
+
+	const noteTypeFieldsCache = new Map<string, Map<string, string>>();
+	const result: StudyCardView[] = [];
+
+	for (const card of dueCards) {
+		const note = await localNoteRepository.findById(card.noteId);
+		if (!note || note.deletedAt !== null) continue;
+
+		const noteType = await localNoteTypeRepository.findById(note.noteTypeId);
+		if (!noteType || noteType.deletedAt !== null) continue;
+
+		let fieldTypeIdToName = noteTypeFieldsCache.get(noteType.id);
+		if (!fieldTypeIdToName) {
+			const fieldTypes = await localNoteFieldTypeRepository.findByNoteTypeId(
+				noteType.id,
+			);
+			fieldTypeIdToName = new Map(fieldTypes.map((ft) => [ft.id, ft.name]));
+			noteTypeFieldsCache.set(noteType.id, fieldTypeIdToName);
+		}
+
+		const fieldValues = await localNoteFieldValueRepository.findByNoteId(
+			note.id,
+		);
+		const fieldValuesMap: Record<string, string> = {};
+		for (const fv of fieldValues) {
+			const name = fieldTypeIdToName.get(fv.noteFieldTypeId);
+			if (name) {
+				fieldValuesMap[name] = fv.value;
+			}
+		}
+
+		result.push({
+			id: card.id,
+			deckId: card.deckId,
+			noteId: card.noteId,
+			isReversed: card.isReversed,
+			state: card.state,
+			noteType: {
+				frontTemplate: noteType.frontTemplate,
+				backTemplate: noteType.backTemplate,
+			},
+			fieldValuesMap,
+		});
+	}
+
+	return result;
+}