import 'dart:async';
import 'dart:convert';
import 'package:flutter_foreground_task/flutter_foreground_task.dart';
import 'package:telephony/telephony.dart' as tel;
import 'package:shared_preferences/shared_preferences.dart';
import 'package:http/http.dart' as http;
import '../models/sms_message.dart';

class SmsForegroundHandler extends TaskHandler {
  StreamSubscription? _smsSub;
  int _uploadedCount = 0;

  @override
  Future<void> onStart(DateTime timestamp, TaskStarter starter) async {
    _startListening();
  }

  @override
  void onRepeatEvent(DateTime timestamp) {}

  @override
  Future<void> onDestroy(DateTime timestamp) async {
    _smsSub?.cancel();
  }

  @override
  void onNotificationPressed() {
    FlutterForegroundTask.launchApp('/');
  }

  void _startListening() async {
    final telephony = tel.Telephony.instance;
    final prefs = await SharedPreferences.getInstance();
    final baseUrl = prefs.getString('server_url') ?? '';
    final token = prefs.getString('token') ?? '';

    telephony.listenIncomingSms(
      onNewMessage: (tel.SmsMessage sms) async {
        final msg = SmsMessage(
          phoneNumber: sms.address ?? '',
          contactName: sms.address,
          content: sms.body ?? '',
          type: 'received',
          smsDate: DateTime.now().toUtc().toIso8601String(),
        );

        if (baseUrl.isNotEmpty && token.isNotEmpty) {
          try {
            await http.post(
              Uri.parse('$baseUrl/api/sms/upload'),
              headers: {
                'Content-Type': 'application/json',
                'Authorization': 'Bearer $token',
              },
              body: jsonEncode([msg.toJson()]),
            );
            _uploadedCount++;
            FlutterForegroundTask.updateService(
              notificationText: '已自动上传 $_uploadedCount 条短信',
            );
          } catch (_) {
            FlutterForegroundTask.updateService(
              notificationText: '上传失败，等待重试... (已上传 $_uploadedCount 条)',
            );
          }
        }
      },
      listenInBackground: false,
    );
  }
}

@pragma('vm:entry-point')
void startCallback() {
  FlutterForegroundTask.setTaskHandler(SmsForegroundHandler());
}