import 'dart:convert';
import 'package:http/http.dart' as http;
import 'package:p_tits_pas/models/user.dart';
import 'package:p_tits_pas/models/parent_model.dart';
import 'package:p_tits_pas/models/assistante_maternelle_model.dart';
import 'package:p_tits_pas/models/pending_family.dart';
import 'package:p_tits_pas/models/dossier_unifie.dart';
import 'package:p_tits_pas/services/api/api_config.dart';
import 'package:p_tits_pas/services/api/tokenService.dart';

class UserService {
  static Future<Map<String, String>> _headers() async {
    final token = await TokenService.getToken();
    return token != null
        ? ApiConfig.authHeaders(token)
        : Map<String, String>.from(ApiConfig.headers);
  }

  static String? _toStr(dynamic v) {
    if (v == null) return null;
    if (v is String) return v;
    return v.toString();
  }

  static String _errMessage(dynamic err) {
    if (err == null) return 'Erreur inconnue';
    if (err is String) return err;
    if (err is Map) {
      final m = err['message'];
      if (m is String) return m;
      if (m is Map && m['message'] is String) return m['message'] as String;
      if (m != null) return _toStr(m) ?? 'Erreur inconnue';
    }
    return _toStr(err) ?? 'Erreur inconnue';
  }

  /// Utilisateurs en attente de validation (GET /users/pending). Ticket #107.
  static Future<List<AppUser>> getPendingUsers({String? role}) async {
    final query = role != null ? '?role=$role' : '';
    final response = await http.get(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.users}/pending$query'),
      headers: await _headers(),
    );
    if (response.statusCode != 200) {
      try {
        final err = jsonDecode(response.body);
        throw Exception(_errMessage(err is Map ? err['message'] : err));
      } catch (e) {
        if (e is Exception) rethrow;
        throw Exception('Erreur chargement comptes en attente (${response.statusCode})');
      }
    }
    try {
      final decoded = jsonDecode(response.body);
      final data = decoded is List ? decoded as List<dynamic> : <dynamic>[];
      return data
          .where((e) => e is Map<String, dynamic>)
          .map((e) => AppUser.fromJson(Map<String, dynamic>.from(e as Map)))
          .toList();
    } catch (e) {
      throw Exception('Réponse invalide (comptes en attente): ${e is Exception ? e.toString() : "format inattendu"}');
    }
  }

  /// Familles en attente (une entrée par famille). GET /parents/pending-families. Ticket #107.
  static Future<List<PendingFamily>> getPendingFamilies() async {
    final response = await http.get(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.parents}/pending-families'),
      headers: await _headers(),
    );
    if (response.statusCode != 200) {
      try {
        final err = jsonDecode(response.body);
        throw Exception(_errMessage(err is Map ? err['message'] : err));
      } catch (e) {
        if (e is Exception) rethrow;
        throw Exception('Erreur chargement familles en attente (${response.statusCode})');
      }
    }
    try {
      final decoded = jsonDecode(response.body);
      final data = decoded is List ? decoded as List<dynamic> : <dynamic>[];
      return data
          .where((e) => e is Map)
          .map((e) => PendingFamily.fromJson(Map<String, dynamic>.from(e as Map)))
          .toList();
    } catch (e) {
      throw Exception('Réponse invalide (familles en attente): ${e is Exception ? e.toString() : "format inattendu"}');
    }
  }

  /// Dossier unifié par numéro (AM ou famille). GET /dossiers/:numeroDossier. Ticket #119, #107.
  static Future<DossierUnifie> getDossier(String numeroDossier) async {
    final encoded = Uri.encodeComponent(numeroDossier);
    final response = await http.get(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.dossiers}/$encoded'),
      headers: await _headers(),
    );
    if (response.statusCode == 404) {
      throw Exception('Aucun dossier avec ce numéro.');
    }
    if (response.statusCode != 200) {
      try {
        final err = jsonDecode(response.body);
        throw Exception(_errMessage(err is Map ? err['message'] : err));
      } catch (e) {
        if (e is Exception) rethrow;
        throw Exception('Erreur chargement dossier (${response.statusCode})');
      }
    }
    try {
      final decoded = jsonDecode(response.body);
      if (decoded is! Map<String, dynamic>) {
        throw FormatException('Réponse invalide');
      }
      return DossierUnifie.fromJson(Map<String, dynamic>.from(decoded));
    } catch (e) {
      if (e is FormatException) rethrow;
      throw Exception('Réponse invalide (dossier): ${e is Exception ? e.toString() : "format inattendu"}');
    }
  }

  /// Valider un utilisateur (AM). PATCH /users/:id/valider. Ticket #108.
  static Future<AppUser> validateUser(String userId, {String? comment}) async {
    final response = await http.patch(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.users}/$userId/valider'),
      headers: await _headers(),
      body: jsonEncode(comment != null ? {'comment': comment} : {}),
    );
    if (response.statusCode != 200) {
      try {
        final err = jsonDecode(response.body);
        throw Exception(_errMessage(err is Map ? err['message'] : err));
      } catch (e) {
        if (e is Exception) rethrow;
        throw Exception('Erreur validation (${response.statusCode})');
      }
    }
    final data = jsonDecode(response.body);
    return AppUser.fromJson(Map<String, dynamic>.from(data is Map ? data : {}));
  }

  /// Valider tout le dossier famille. POST /parents/:parentId/valider-dossier. Ticket #108.
  static Future<List<AppUser>> validerDossierFamille(String parentId, {String? comment}) async {
    final response = await http.post(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.parents}/$parentId/valider-dossier'),
      headers: await _headers(),
      body: jsonEncode(comment != null ? {'comment': comment} : {}),
    );
    if (response.statusCode != 200) {
      try {
        final err = jsonDecode(response.body);
        throw Exception(_errMessage(err is Map ? err['message'] : err));
      } catch (e) {
        if (e is Exception) rethrow;
        throw Exception('Erreur validation dossier famille (${response.statusCode})');
      }
    }
    final data = jsonDecode(response.body);
    final list = data is List ? data : [];
    return list.map((e) => AppUser.fromJson(Map<String, dynamic>.from(e as Map))).toList();
  }

  // Récupérer la liste des gestionnaires (endpoint dédié)
  static Future<List<AppUser>> getGestionnaires() async {
    final response = await http.get(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.gestionnaires}'),
      headers: await _headers(),
    );

    if (response.statusCode != 200) {
      final err = jsonDecode(response.body) as Map<String, dynamic>?;
      throw Exception(
          _toStr(err?['message']) ?? 'Erreur chargement gestionnaires');
    }

    final List<dynamic> data = jsonDecode(response.body);
    return data.map((e) => AppUser.fromJson(e)).toList();
  }

  static Future<AppUser> createGestionnaire({
    required String nom,
    required String prenom,
    required String email,
    required String password,
    required String telephone,
    String? relaisId,
  }) async {
    final response = await http.post(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.gestionnaires}'),
      headers: await _headers(),
      body: jsonEncode(<String, dynamic>{
        'nom': nom,
        'prenom': prenom,
        'email': email,
        'password': password,
        'telephone': telephone,
        'cguAccepted': true,
        'relaisId': relaisId,
      }),
    );

    if (response.statusCode != 200 && response.statusCode != 201) {
      final decoded = jsonDecode(response.body);
      if (decoded is Map<String, dynamic>) {
        final message = decoded['message'];
        if (message is List && message.isNotEmpty) {
          throw Exception(message.join(' - '));
        }
        throw Exception(_toStr(message) ?? 'Erreur création gestionnaire');
      }
      throw Exception('Erreur création gestionnaire');
    }

    final data = jsonDecode(response.body) as Map<String, dynamic>;
    return AppUser.fromJson(data);
  }

  static Future<AppUser> createAdministrateur({
    required String nom,
    required String prenom,
    required String email,
    required String password,
    required String telephone,
  }) async {
    final response = await http.post(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.users}/admin'),
      headers: await _headers(),
      body: jsonEncode(<String, dynamic>{
        'nom': nom,
        'prenom': prenom,
        'email': email,
        'password': password,
        'telephone': telephone,
      }),
    );

    if (response.statusCode != 200 && response.statusCode != 201) {
      final decoded = jsonDecode(response.body);
      if (decoded is Map<String, dynamic>) {
        final message = decoded['message'];
        if (message is List && message.isNotEmpty) {
          throw Exception(message.join(' - '));
        }
        throw Exception(_toStr(message) ?? 'Erreur création administrateur');
      }
      throw Exception('Erreur création administrateur');
    }

    final data = jsonDecode(response.body) as Map<String, dynamic>;
    return AppUser.fromJson(data);
  }

  // Récupérer la liste des parents
  static Future<List<ParentModel>> getParents() async {
    final response = await http.get(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.parents}'),
      headers: await _headers(),
    );

    if (response.statusCode != 200) {
      final err = jsonDecode(response.body) as Map<String, dynamic>?;
      throw Exception(_toStr(err?['message']) ?? 'Erreur chargement parents');
    }

    final List<dynamic> data = jsonDecode(response.body);
    return data.map((e) => ParentModel.fromJson(e)).toList();
  }

  // Récupérer la liste des assistantes maternelles
  static Future<List<AssistanteMaternelleModel>>
      getAssistantesMaternelles() async {
    final response = await http.get(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.assistantesMaternelles}'),
      headers: await _headers(),
    );

    if (response.statusCode != 200) {
      final err = jsonDecode(response.body) as Map<String, dynamic>?;
      throw Exception(_toStr(err?['message']) ?? 'Erreur chargement AM');
    }

    final List<dynamic> data = jsonDecode(response.body);
    return data.map((e) => AssistanteMaternelleModel.fromJson(e)).toList();
  }

  // Récupérer la liste des administrateurs (via /users filtré ou autre)
  // Pour l'instant on va utiliser /users et filtrer côté client si on est super admin
  static Future<List<AppUser>> getAdministrateurs() async {
    // TODO: Endpoint dédié ou filtrage
    // En attendant, on retourne une liste vide ou on tente /users
    try {
      final response = await http.get(
        Uri.parse('${ApiConfig.baseUrl}${ApiConfig.users}'),
        headers: await _headers(),
      );

      if (response.statusCode == 200) {
        final List<dynamic> data = jsonDecode(response.body);
        return data
            .map((e) => AppUser.fromJson(e))
            .where((u) => u.role == 'administrateur' || u.role == 'super_admin')
            .toList();
      }
    } catch (e) {
      // On garde un fallback vide pour ne pas bloquer l'UI admin.
    }
    return [];
  }

  static Future<AppUser> createAdmin({
    required String nom,
    required String prenom,
    required String email,
    required String password,
    required String telephone,
  }) async {
    final response = await http.post(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.users}/admin'),
      headers: await _headers(),
      body: jsonEncode(<String, dynamic>{
        'nom': nom,
        'prenom': prenom,
        'email': email,
        'password': password,
        'telephone': telephone,
      }),
    );

    if (response.statusCode != 200 && response.statusCode != 201) {
      final decoded = jsonDecode(response.body);
      if (decoded is Map<String, dynamic>) {
        final message = decoded['message'];
        if (message is List && message.isNotEmpty) {
          throw Exception(message.join(' - '));
        }
        throw Exception(_toStr(message) ?? 'Erreur création administrateur');
      }
      throw Exception('Erreur création administrateur');
    }

    final data = jsonDecode(response.body) as Map<String, dynamic>;
    return AppUser.fromJson(data);
  }

  static Future<AppUser> updateAdmin({
    required String adminId,
    required String nom,
    required String prenom,
    required String email,
    required String telephone,
    String? password,
  }) async {
    final body = <String, dynamic>{
      'nom': nom,
      'prenom': prenom,
      'email': email,
      'telephone': telephone,
    };

    if (password != null && password.trim().isNotEmpty) {
      body['password'] = password.trim();
    }

    final response = await http.patch(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.users}/$adminId'),
      headers: await _headers(),
      body: jsonEncode(body),
    );

    if (response.statusCode != 200) {
      final decoded = jsonDecode(response.body);
      if (decoded is Map<String, dynamic>) {
        final message = decoded['message'];
        if (message is List && message.isNotEmpty) {
          throw Exception(message.join(' - '));
        }
        throw Exception(_toStr(message) ?? 'Erreur modification administrateur');
      }
      throw Exception('Erreur modification administrateur');
    }

    final data = jsonDecode(response.body) as Map<String, dynamic>;
    return AppUser.fromJson(data);
  }

  static Future<void> updateGestionnaireRelais({
    required String gestionnaireId,
    required String? relaisId,
  }) async {
    final response = await http.patch(
      Uri.parse(
          '${ApiConfig.baseUrl}${ApiConfig.gestionnaires}/$gestionnaireId'),
      headers: await _headers(),
      body: jsonEncode(<String, dynamic>{'relaisId': relaisId}),
    );

    if (response.statusCode != 200 && response.statusCode != 204) {
      final err = jsonDecode(response.body) as Map<String, dynamic>?;
      throw Exception(
        _toStr(err?['message']) ?? 'Erreur rattachement relais au gestionnaire',
      );
    }
  }

  static Future<AppUser> updateGestionnaire({
    required String gestionnaireId,
    required String nom,
    required String prenom,
    required String email,
    String? telephone,
    required String? relaisId,
    String? password,
  }) async {
    final body = <String, dynamic>{
      'nom': nom,
      'prenom': prenom,
      'email': email,
      'relaisId': relaisId,
    };

    if (telephone != null && telephone.trim().isNotEmpty) {
      body['telephone'] = telephone.trim();
    }

    if (password != null && password.trim().isNotEmpty) {
      body['password'] = password.trim();
    }

    final response = await http.patch(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.gestionnaires}/$gestionnaireId'),
      headers: await _headers(),
      body: jsonEncode(body),
    );

    if (response.statusCode != 200) {
      final decoded = jsonDecode(response.body);
      if (decoded is Map<String, dynamic>) {
        final message = decoded['message'];
        if (message is List && message.isNotEmpty) {
          throw Exception(message.join(' - '));
        }
        throw Exception(_toStr(message) ?? 'Erreur modification gestionnaire');
      }
      throw Exception('Erreur modification gestionnaire');
    }

    final data = jsonDecode(response.body) as Map<String, dynamic>;
    return AppUser.fromJson(data);
  }

  static Future<AppUser> updateAdministrateur({
    required String adminId,
    required String nom,
    required String prenom,
    required String email,
    String? telephone,
    String? password,
  }) async {
    final body = <String, dynamic>{
      'nom': nom,
      'prenom': prenom,
      'email': email,
    };

    if (telephone != null && telephone.trim().isNotEmpty) {
      body['telephone'] = telephone.trim();
    }

    if (password != null && password.trim().isNotEmpty) {
      body['password'] = password.trim();
    }

    final response = await http.patch(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.users}/$adminId'),
      headers: await _headers(),
      body: jsonEncode(body),
    );

    if (response.statusCode != 200) {
      final decoded = jsonDecode(response.body);
      if (decoded is Map<String, dynamic>) {
        final message = decoded['message'];
        if (message is List && message.isNotEmpty) {
          throw Exception(message.join(' - '));
        }
        throw Exception(_toStr(message) ?? 'Erreur modification administrateur');
      }
      throw Exception('Erreur modification administrateur');
    }

    final data = jsonDecode(response.body) as Map<String, dynamic>;
    return AppUser.fromJson(data);
  }

  static Future<void> deleteUser(String userId) async {
    final response = await http.delete(
      Uri.parse('${ApiConfig.baseUrl}${ApiConfig.users}/$userId'),
      headers: await _headers(),
    );

    if (response.statusCode != 200 && response.statusCode != 204) {
      final decoded = jsonDecode(response.body);
      if (decoded is Map<String, dynamic>) {
        final message = decoded['message'];
        if (message is List && message.isNotEmpty) {
          throw Exception(message.join(' - '));
        }
        throw Exception(_toStr(message) ?? 'Erreur suppression utilisateur');
      }
      throw Exception('Erreur suppression utilisateur');
    }
  }
}