import 'dart:io';
import 'package:dio/dio.dart';
import 'package:http_parser/http_parser.dart';
import 'package:injectable/injectable.dart';
import '../../../../core/config/environment.dart';
import '../../../../core/utils/logger.dart';

/// Service pour uploader des documents (pièces justificatives LCB-FT)
@lazySingleton
class DocumentUploadService {
  final Dio _dio;

  DocumentUploadService(this._dio);

  /// Upload un fichier vers le backend
  /// Retourne l'ID du document créé
  Future<String> uploadDocument({
    required File file,
    String? description,
    String typeDocument = 'PIECE_JUSTIFICATIVE',
  }) async {
    try {
      final fileName = file.path.split('/').last;
      final fileExtension = fileName.split('.').last.toLowerCase();

      // Déterminer le type MIME
      String contentType;
      if (fileExtension == 'pdf') {
        contentType = 'application/pdf';
      } else if (fileExtension == 'jpg' || fileExtension == 'jpeg') {
        contentType = 'image/jpeg';
      } else if (fileExtension == 'png') {
        contentType = 'image/png';
      } else if (fileExtension == 'gif') {
        contentType = 'image/gif';
      } else {
        throw Exception('Type de fichier non supporté: .$fileExtension');
      }

      // Vérifier la taille (max 5 MB)
      final fileSize = await file.length();
      const maxSize = 5 * 1024 * 1024; // 5 MB
      if (fileSize > maxSize) {
        throw Exception('Fichier trop volumineux. Taille max: 5 MB');
      }

      // Créer le FormData
      final formData = FormData.fromMap({
        'file': await MultipartFile.fromFile(
          file.path,
          filename: fileName,
          contentType: MediaType.parse(contentType),
        ),
        if (description != null && description.isNotEmpty)
          'description': description,
        'typeDocument': typeDocument,
      });

      AppLogger.debug('Upload de $fileName (${_formatBytes(fileSize)})');

      final response = await _dio.post(
        '${AppConfig.apiBaseUrl}/documents/upload',
        data: formData,
        options: Options(
          headers: {
            'Content-Type': 'multipart/form-data',
          },
        ),
      );

      if (response.statusCode == 201 && response.data != null) {
        final documentId = response.data['id'] as String;
        AppLogger.info('Document uploadé avec succès: $documentId');
        return documentId;
      } else {
        throw Exception('Erreur lors de l\'upload: ${response.statusCode}');
      }
    } on DioException catch (e) {
      AppLogger.error('Erreur Dio lors de l\'upload: ${e.message}', error: e);
      if (e.response?.data != null && e.response!.data['error'] != null) {
        throw Exception(e.response!.data['error']);
      }
      throw Exception('Erreur réseau lors de l\'upload');
    } catch (e) {
      AppLogger.error('Erreur lors de l\'upload du document', error: e);
      rethrow;
    }
  }

  String _formatBytes(int bytes) {
    if (bytes < 1024) {
      return '$bytes B';
    } else if (bytes < 1024 * 1024) {
      return '${(bytes / 1024).toStringAsFixed(2)} KB';
    } else {
      return '${(bytes / (1024 * 1024)).toStringAsFixed(2)} MB';
    }
  }
}