import 'dart:async';
import 'dart:convert';
import 'dart:io';

import 'package:device_info_plus/device_info_plus.dart';
import 'package:dio/dio.dart';
import 'package:package_info_plus/package_info_plus.dart';

import '../../../../push/push_registration_store.dart';
import '../../../../push/push_registration_type.dart';
import '../../errors/marianumconnect_error.dart';
import '../../marianumconnect_api.dart';
import '../../marianumconnect_endpoint.dart';
import 'telemetry_device_id.dart';

/// Sends a telemetry heartbeat to MarianumConnect (`POST me/telemetry`) —
/// upserts the stable install id, platform, app version and device info. Sent
/// once on app start and again once push registration completes that session
/// (so a fresh registration isn't under-reported until the next launch).
/// Bearer-authenticated via the shared dio interceptor. Replaces the legacy
/// mhsl.eu `server/userIndex/update` call.
class TelemetryHeartbeat {
  final Dio _dio;

  TelemetryHeartbeat({Dio? dio}) : _dio = dio ?? MarianumConnectApi.dio();

  /// Fire-and-forget: schedules a heartbeat and swallows any error, so a failed
  /// send never disrupts app start. Used from the app shell's initState and
  /// re-emitted once push registration completes (see `_MainState._syncPush`).
  static void report({required bool notificationsEnabled}) {
    unawaited(
      TelemetryHeartbeat()
          .send(notificationsEnabled: notificationsEnabled)
          .catchError((Object _) {}),
    );
  }

  Future<void> send({required bool notificationsEnabled}) async {
    try {
      final info = DeviceInfoPlugin();
      final package = await PackageInfo.fromPlatform();
      final deviceIdentifier = await TelemetryDeviceId.resolve();
      final pushDeviceIdentifier = await const PushRegistrationStore()
          .deviceIdentifier(PushRegistrationType.general);

      var platform = 'unknown';
      String? deviceModel;
      String? osVersion;
      var raw = <String, dynamic>{};
      if (Platform.isAndroid) {
        platform = 'android';
        final androidInfo = await info.androidInfo;
        deviceModel = androidInfo.model;
        osVersion = androidInfo.version.release;
        raw = androidInfo.data;
      } else if (Platform.isIOS) {
        platform = 'ios';
        final appleInfo = await info.iosInfo;
        deviceModel = appleInfo.utsname.machine;
        osVersion = appleInfo.systemVersion;
        raw = appleInfo.data;
      }

      await _dio.post<void>(
        MarianumConnectEndpoint.resolve('me/telemetry'),
        data: {
          'deviceIdentifier': deviceIdentifier,
          // `pushDeviceIdentifier` reflects a *completed* registration and is
          // absent until it lands; `pushEnabled` carries the user's intent
          // (the notification toggle) so the backend can tell "user wants push"
          // apart from "registration not finished yet".
          'pushDeviceIdentifier': ?pushDeviceIdentifier,
          'pushEnabled': notificationsEnabled,
          'platform': platform,
          'appVersion': package.version,
          'appBuild': int.tryParse(package.buildNumber),
          'deviceModel': deviceModel,
          'osVersion': osVersion,
          'deviceInfo': jsonEncode(raw),
        },
      );
    } on DioException catch (e) {
      throw mapMarianumConnectError(e);
    }
  }
}