import 'dart:convert';

import 'package:drift/drift.dart' show Value;
import 'package:uto_manager/domain/entities/authorized_rank.dart';
import 'package:uto_manager/domain/entities/personnel_record.dart' as domain;
import 'package:uto_manager/domain/repositories/personnel_repository.dart';
import 'package:uto_manager/domain/value_objects/duty_mos.dart';
import 'package:uto_manager/infrastructure/database/app_database.dart';
import 'package:uto_manager/infrastructure/database/daos/personnel_dao.dart';

/// Drift-backed implementation of [PersonnelRepository].
///
/// Converts between Drift [PersonnelData] rows and domain
/// [domain.PersonnelRecord] entities. All persistence is handled via
/// [PersonnelDao].
class DriftPersonnelRepository implements PersonnelRepository {
  const DriftPersonnelRepository({required this.dao});

  final PersonnelDao dao;

  // ---------------------------------------------------------------------------
  // Mapping helpers
  // ---------------------------------------------------------------------------

  domain.PersonnelRecord _toDomain(PersonnelData row) {
    return domain.PersonnelRecord(
      soldierId: row.soldierId,
      name: row.name,
      primaryMos: DutyMos.unvalidated(row.primaryMos),
      payGrade: AuthorizedRank.values.firstWhere((r) => r.name == row.payGrade),
      qualifications: (jsonDecode(row.qualifications) as List<dynamic>).cast<String>(),
      readinessState: domain.ReadinessState.values.firstWhere(
        (s) => s.name == row.readinessState,
      ),
      assignedSlotId: row.assignedSlotId,
    );
  }

  PersonnelCompanion _toCompanion(domain.PersonnelRecord record) {
    return PersonnelCompanion.insert(
      soldierId: record.soldierId,
      name: record.name,
      primaryMos: record.primaryMos.code,
      payGrade: record.payGrade.name,
      qualifications: jsonEncode(record.qualifications),
      readinessState: record.readinessState.name,
      assignedSlotId: Value(record.assignedSlotId),
    );
  }

  // ---------------------------------------------------------------------------
  // PersonnelRepository implementation
  // ---------------------------------------------------------------------------

  @override
  Future<List<domain.PersonnelRecord>> getAll() async {
    final rows = await dao.getAllPersonnel();
    return rows.map(_toDomain).toList();
  }

  @override
  Future<domain.PersonnelRecord?> getById(String soldierId) async {
    final row = await dao.getPersonnelById(soldierId);
    return row == null ? null : _toDomain(row);
  }

  @override
  Future<List<domain.PersonnelRecord>> getBySlot(String slotId) async {
    final rows = await dao.getBySlot(slotId);
    return rows.map(_toDomain).toList();
  }

  @override
  Future<List<domain.PersonnelRecord>> getUnassigned() async {
    final rows = await dao.getUnassigned();
    return rows.map(_toDomain).toList();
  }

  @override
  Future<List<domain.PersonnelRecord>> getByMos(DutyMos primaryMos) async {
    final rows = await dao.getByMos(primaryMos.code);
    return rows.map(_toDomain).toList();
  }

  @override
  Future<List<domain.PersonnelRecord>> getByPayGrade(AuthorizedRank payGrade) async {
    final rows = await dao.getByPayGrade(payGrade.name);
    return rows.map(_toDomain).toList();
  }

  @override
  Future<void> insert(domain.PersonnelRecord record) async {
    final existing = await dao.getPersonnelById(record.soldierId);
    if (existing != null) {
      throw StateError('Personnel ${record.soldierId} already exists.');
    }
    await dao.insertPersonnel(_toCompanion(record));
  }

  @override
  Future<void> insertAll(List<domain.PersonnelRecord> records) async {
    await dao.insertAllPersonnel(records.map(_toCompanion).toList());
  }

  @override
  Future<void> update(domain.PersonnelRecord record) async {
    final existing = await dao.getPersonnelById(record.soldierId);
    if (existing == null) {
      throw StateError('Personnel ${record.soldierId} not found.');
    }
    await dao.updatePersonnel(_toCompanion(record));
  }

  @override
  Future<void> delete(String soldierId) async {
    await dao.deletePersonnel(soldierId);
  }

  @override
  Future<void> assignToSlot(String soldierId, String slotId) async {
    await dao.assignToSlot(soldierId, slotId);
  }

  @override
  Future<void> unassignFromSlot(String soldierId) async {
    await dao.unassignFromSlot(soldierId);
  }

  @override
  Stream<List<domain.PersonnelRecord>> watchAll() {
    return dao.watchAllPersonnel().map((rows) => rows.map(_toDomain).toList());
  }

  @override
  Stream<List<domain.PersonnelRecord>> watchUnassigned() {
    return dao.watchUnassigned().map((rows) => rows.map(_toDomain).toList());
  }

  @override
  Future<void> deleteAll() async {
    await dao.deleteAllPersonnel();
  }
}