import 'package:drift/drift.dart';
import 'package:uto_manager/infrastructure/database/app_database.dart';

part 'position_slot_dao.g.dart';

/// Data Access Object for [PositionSlots] table operations.
@DriftAccessor(tables: [PositionSlots])
class PositionSlotDao extends DatabaseAccessor<AppDatabase> with _$PositionSlotDaoMixin {
  PositionSlotDao(super.db);

  /// Returns all position slot rows.
  Future<List<PositionSlot>> getAllSlots() => select(positionSlots).get();

  /// Returns the slot with [slotId], or null if not found.
  Future<PositionSlot?> getSlotById(String slotId) =>
      (select(positionSlots)..where((t) => t.slotId.equals(slotId))).getSingleOrNull();

  /// Returns all slots belonging to [unitId].
  Future<List<PositionSlot>> getSlotsByUnit(String unitId) =>
      (select(positionSlots)..where((t) => t.unitId.equals(unitId))).get();

  /// Returns all vacant slots (no assigned personnel).
  Future<List<PositionSlot>> getVacantSlots() =>
      (select(positionSlots)..where((t) => t.assignedPersonnelId.isNull())).get();

  /// Returns all key leader slots.
  Future<List<PositionSlot>> getKeyLeaderSlots() =>
      (select(positionSlots)..where((t) => t.isKeyLeader.equals(true))).get();

  /// Inserts a new position slot row.
  Future<void> insertSlot(PositionSlotsCompanion entry) =>
      into(positionSlots).insert(entry, mode: InsertMode.insertOrFail);

  /// Inserts multiple position slot rows in a single transaction.
  Future<void> insertAllSlots(List<PositionSlotsCompanion> entries) =>
      batch((b) => b.insertAll(positionSlots, entries, mode: InsertMode.insertOrFail));

  /// Updates an existing position slot row.
  Future<bool> updateSlot(PositionSlotsCompanion entry) => update(positionSlots).replace(entry);

  /// Assigns [personnelId] to the slot with [slotId].
  Future<void> assignPersonnel(String slotId, String personnelId) async {
    await (update(positionSlots)..where((t) => t.slotId.equals(slotId))).write(
      PositionSlotsCompanion(assignedPersonnelId: Value(personnelId)),
    );
  }

  /// Clears the personnel assignment for the slot with [slotId].
  Future<void> clearAssignment(String slotId) async {
    await (update(positionSlots)..where((t) => t.slotId.equals(slotId))).write(
      const PositionSlotsCompanion(assignedPersonnelId: Value(null)),
    );
  }

  /// Deletes the slot with [slotId].
  Future<int> deleteSlot(String slotId) =>
      (delete(positionSlots)..where((t) => t.slotId.equals(slotId))).go();

  /// Deletes all slots belonging to [unitId].
  Future<int> deleteSlotsByUnit(String unitId) =>
      (delete(positionSlots)..where((t) => t.unitId.equals(unitId))).go();

  /// Deletes all position slots.
  Future<int> deleteAllSlots() => delete(positionSlots).go();

  /// Returns a stream that emits all slots whenever the table changes.
  Stream<List<PositionSlot>> watchAllSlots() => select(positionSlots).watch();

  /// Returns a stream that emits slots for [unitId] on changes.
  Stream<List<PositionSlot>> watchSlotsByUnit(String unitId) =>
      (select(positionSlots)..where((t) => t.unitId.equals(unitId))).watch();
}