import 'dart:convert';
import 'package:http/http.dart' as http;
import '../models/sms_message.dart';

class ApiService {
  String _baseUrl = '';
  String? _token;

  void configure(String baseUrl, String token) {
    _baseUrl = baseUrl.endsWith('/') ? baseUrl.substring(0, baseUrl.length - 1) : baseUrl;
    _token = token;
  }

  Map<String, String> get _headers => {
        'Content-Type': 'application/json',
        if (_token != null) 'Authorization': 'Bearer $_token',
      };

  Future<String> login(String username, String password) async {
    final res = await http.post(
      Uri.parse('$_baseUrl/api/auth/login'),
      headers: {'Content-Type': 'application/json'},
      body: jsonEncode({'username': username, 'password': password}),
    );
    if (res.statusCode != 200) throw Exception(_error(res));
    return jsonDecode(res.body)['token'];
  }

  Future<String> register(String username, String password) async {
    final res = await http.post(
      Uri.parse('$_baseUrl/api/auth/register'),
      headers: {'Content-Type': 'application/json'},
      body: jsonEncode({'username': username, 'password': password}),
    );
    if (res.statusCode != 201) throw Exception(_error(res));
    return jsonDecode(res.body)['token'];
  }

  Future<int> uploadSms(List<SmsMessage> messages) async {
    final res = await http.post(
      Uri.parse('$_baseUrl/api/sms/upload'),
      headers: _headers,
      body: jsonEncode(messages.map((m) => m.toJson()).toList()),
    );
    if (res.statusCode != 200) throw Exception(_error(res));
    return jsonDecode(res.body)['uploaded'];
  }

  Future<void> registerDevice(String deviceName) async {
    await http.post(
      Uri.parse('$_baseUrl/api/devices/register'),
      headers: _headers,
      body: jsonEncode({'device_name': deviceName}),
    );
  }

  String _error(http.Response res) {
    try {
      return jsonDecode(res.body)['error'] ?? 'Request failed';
    } catch (_) {
      return 'Request failed (${res.statusCode})';
    }
  }
}