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

class ApiException implements Exception {
  final int statusCode;
  final String message;

  const ApiException({required this.statusCode, required this.message});

  @override
  String toString() => 'ApiException($statusCode): $message';
}

class ApiClient {
  final String baseUrl;
  String? _token;

  ApiClient({required this.baseUrl});

  void setToken(String token) => _token = token;
  void clearToken() => _token = null;

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

  Future<dynamic> post(String path, Map<String, dynamic> body) async {
    final response = await http.post(
      Uri.parse('$baseUrl$path'),
      headers: _headers,
      body: jsonEncode(body),
    );
    return _handleResponse(response);
  }

  Future<dynamic> get(String path) async {
    final response = await http.get(
      Uri.parse('$baseUrl$path'),
      headers: _headers,
    );
    return _handleResponse(response);
  }

  dynamic _handleResponse(http.Response response) {
    if (response.body.isEmpty) return null;
    final data = jsonDecode(response.body);
    if (response.statusCode >= 200 && response.statusCode < 300) {
      return data;
    }
    final detail = data is Map ? (data['detail'] ?? 'Unknown error') : 'Unknown error';
    throw ApiException(statusCode: response.statusCode, message: detail.toString());
  }
}