import 'package:drift/drift.dart';
import 'package:trainhub_flutter/data/database/app_database.dart';

part 'knowledge_chunk_dao.g.dart';

@DriftAccessor(tables: [KnowledgeChunks])
class KnowledgeChunkDao extends DatabaseAccessor<AppDatabase>
    with _$KnowledgeChunkDaoMixin {
  KnowledgeChunkDao(super.db);

  Future<void> insertChunk(KnowledgeChunksCompanion entry) =>
      into(knowledgeChunks).insert(entry);

  /// Returns every stored chunk, including its JSON-encoded embedding.
  /// Loaded into memory for in-process cosine similarity scoring.
  Future<List<KnowledgeChunk>> getAllChunks() =>
      (select(knowledgeChunks)
            ..orderBy([
              (t) =>
                  OrderingTerm(expression: t.createdAt, mode: OrderingMode.asc)
            ]))
          .get();

  Future<int> getCount() async {
    final rows = await select(knowledgeChunks).get();
    return rows.length;
  }

  Future<void> deleteAll() => delete(knowledgeChunks).go();

  Future<void> deleteBySourceId(String sourceId) =>
      (delete(knowledgeChunks)
            ..where((t) => t.sourceId.equals(sourceId)))
          .go();
}