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

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

import '../config/intra_config.dart';
import 'intra_api_exception.dart';
import 'intra_auth_service.dart';

class IntraUserService {
  IntraUserService._();
  static final IntraUserService instance = IntraUserService._();

  final IntraAuthService _auth = IntraAuthService.instance;

  /// Recherche par login — réutilise le token OAuth (pas de nouvel OAuth).
  Future<Map<String, dynamic>> fetchUserByLogin(String login) async {
    final trimmed = login.trim();
    if (trimmed.isEmpty) {
      throw const IntraApiErrorException('Saisis un login');
    }
    if (!_auth.isAuthenticated) {
      throw const IntraNotAuthenticatedException();
    }

    final uri = Uri.parse('${IntraConfig.apiBaseUrl}/users').replace(
      queryParameters: {'filter[login]': trimmed},
    );

    try {
      final response = await http.get(uri, headers: _auth.authHeaders());
      return _parseUserListResponse(response, trimmed);
    } on IntraApiException {
      rethrow;
    } on SocketException {
      throw const IntraNetworkException();
    } on http.ClientException {
      throw const IntraNetworkException();
    }
  }

  Map<String, dynamic> _parseUserListResponse(
    http.Response response,
    String login,
  ) {
    if (response.statusCode == 401) {
      throw const IntraUnauthorizedException();
    }
    if (response.statusCode != 200) {
      throw IntraApiErrorException(
        'Erreur API (${response.statusCode})',
      );
    }

    final decoded = jsonDecode(response.body);
    if (decoded is! List) {
      throw IntraApiErrorException('Réponse API inattendue');
    }
    if (decoded.isEmpty) {
      throw const IntraUserNotFoundException();
    }

    final user = decoded.first;
    if (user is! Map<String, dynamic>) {
      throw IntraApiErrorException('Réponse API inattendue');
    }
    return user;
  }
}