import 'dart:convert';
import 'dart:math';

import 'package:manager_api_new/api.dart';
import 'package:tablet_app/client.dart';

class StatisticsService {
  final Client clientAPI;
  final String? instanceId;
  final String? configurationId;
  final String? appType; // "Mobile" or "Tablet"
  final String? language;
  final String sessionId;

  StatisticsService({
    required this.clientAPI,
    required this.instanceId,
    required this.configurationId,
    this.appType = 'Tablet',
    this.language,
  }) : sessionId = _generateSessionId();

  static String _generateSessionId() {
    final rand = Random();
    final bytes = List<int>.generate(16, (_) => rand.nextInt(256));
    return bytes.map((b) => b.toRadixString(16).padLeft(2, '0')).join();
  }

  Future<void> track(
    String eventType, {
    String? sectionId,
    int? durationSeconds,
    Map<String, dynamic>? metadata,
  }) async {
    try {
      await clientAPI.statsApi!.statsTrackEvent(VisitEventDTO(
        instanceId: instanceId ?? '',
        configurationId: configurationId,
        sectionId: sectionId,
        sessionId: sessionId,
        eventType: eventType,
        appType: appType,
        language: language,
        durationSeconds: durationSeconds,
        metadata: metadata != null ? jsonEncode(metadata) : null,
        timestamp: DateTime.now(),
      ));
    } catch (_) {
      // fire-and-forget — never block the UI on stats errors
    }
  }
}