dmc/app/lib/services/database/mission_repository.dart

import 'dart:convert';

import 'package:drift/drift.dart';

import '../../domain/waypoint/flat_waypoint_list.dart';
import 'app_database.dart';
import 'waypoint_json_codec.dart';

/// Kopfzeilen-taugliche Zusammenfassung einer gespeicherten Mission, ohne
/// die komplette Wegpunktliste zu materialisieren (fuer die Missionsliste
/// im Verwaltungsmenue, Doku 3.6/7.1).
class MissionSummary {
  const MissionSummary({
    required this.id,
    required this.name,
    required this.placeName,
    required this.waypointCount,
    required this.updatedAt,
  });

  final int id;
  final String name;
  final String? placeName;
  final int waypointCount;
  final DateTime updatedAt;
}

class LoadedMission {
  const LoadedMission({
    required this.name,
    required this.placeName,
    required this.createdAt,
    required this.waypoints,
  });

  final String name;
  final String? placeName;
  final DateTime createdAt;
  final List<Waypoint> waypoints;
}

/// Persistenz-Zugriff fuer Missionen (Doku 4.15): kapselt die Drift-Tabelle
/// und die JSON-(De-)Serialisierung der Wegpunktliste - die Domain-Schicht
/// (Waypoint) kennt bewusst kein JSON, siehe flat_waypoint_list.dart.
class MissionRepository {
  MissionRepository(this._db);

  final AppDatabase _db;

  Stream<List<MissionSummary>> watchSummaries() {
    return _db.select(_db.missions).watch().map((rows) {
      final summaries = [
        for (final row in rows)
          MissionSummary(
            id: row.id,
            name: row.name,
            placeName: row.location,
            waypointCount:
                (jsonDecode(row.waypointsJson) as List).length,
            updatedAt: row.updatedAt,
          ),
      ];
      return summaries;
    });
  }

  Future<LoadedMission?> load(int id) async {
    final row = await (_db.select(_db.missions)
          ..where((m) => m.id.equals(id)))
        .getSingleOrNull();
    if (row == null) return null;
    final decoded = jsonDecode(row.waypointsJson) as List;
    return LoadedMission(
      name: row.name,
      placeName: row.location,
      createdAt: row.createdAt,
      waypoints: [
        for (final entry in decoded) waypointFromJson(entry as Map<String, dynamic>),
      ],
    );
  }

  /// Legt eine neue Mission an oder ueberschreibt die bestehende mit [id] -
  /// analog saveCurrentMission()/Mission.toRecord() im HTML-Demonstrator
  /// (find-or-insert nach id). Gibt die (ggf. neu vergebene) id zurueck.
  Future<int> upsert({
    int? id,
    required String name,
    String? placeName,
    required List<Waypoint> waypoints,
  }) async {
    final waypointsJson = jsonEncode([for (final w in waypoints) waypointToJson(w)]);
    final companion = MissionsCompanion(
      name: Value(name),
      location: Value(placeName),
      updatedAt: Value(DateTime.now()),
      waypointsJson: Value(waypointsJson),
    );
    if (id == null) {
      return _db.into(_db.missions).insert(companion);
    }
    final existing = await (_db.select(_db.missions)
          ..where((m) => m.id.equals(id)))
        .getSingleOrNull();
    if (existing == null) {
      return _db.into(_db.missions).insert(companion.copyWith(id: Value(id)));
    }
    await (_db.update(_db.missions)..where((m) => m.id.equals(id)))
        .write(companion);
    return id;
  }

  Future<void> rename(int id, String name) async {
    await (_db.update(_db.missions)..where((m) => m.id.equals(id))).write(
      MissionsCompanion(name: Value(name), updatedAt: Value(DateTime.now())),
    );
  }

  Future<void> delete(int id) async {
    await (_db.delete(_db.missions)..where((m) => m.id.equals(id))).go();
  }
}