[BUG] Fix upload attachment

lib/features/composer/data/network/composer_api.dart

@@ -1,7 +1,9 @@
 
+import 'dart:convert';
 import 'dart:io';
 
 import 'package:core/core.dart';
+import 'package:dio/dio.dart';
 import 'package:model/model.dart';
 
 class ComposerAPI {
@@ -11,9 +13,15 @@ class ComposerAPI {
   ComposerAPI(this._dioClient);
 
   Future<UploadResponse> uploadAttachment(UploadRequest uploadRequest) async {
+    final file = File(uploadRequest.fileInfo.filePath);
+    final headerParam = _dioClient.getHeaders();
+    headerParam[HttpHeaders.contentTypeHeader] = uploadRequest.fileInfo.mimeType;
+    headerParam[HttpHeaders.contentLengthHeader] = file.readAsBytesSync().length;
+
     final resultJson = await _dioClient.post(
         Uri.decodeFull(uploadRequest.uploadUrl.toString()),
-        data: File(uploadRequest.fileInfo.filePath).readAsBytesSync());
-    return UploadResponse.fromJson(resultJson);
+        options: Options(headers: headerParam),
+        data: file.openRead());
+    return UploadResponse.fromJson(jsonDecode(resultJson));
   }
 }

model/lib/upload/file_info.dart

@@ -1,5 +1,6 @@
 
 import 'package:equatable/equatable.dart';
+import 'package:mime/mime.dart';
 
 class FileInfo with EquatableMixin {
   final String fileName;
@@ -12,6 +13,8 @@ class FileInfo with EquatableMixin {
     return FileInfo('', '', 0);
   }
 
+  String get mimeType => lookupMimeType(filePath) ?? 'application/json; charset=UTF-8';
+
   @override
   List<Object> get props => [fileName, filePath, fileSize];
 }

model/pubspec.yaml

@@ -57,6 +57,9 @@ dependencies:
   # http_parser
   http_parser: 4.0.0
 
+  # mime
+  mime: 1.0.1
+
 dev_dependencies:
   flutter_test:
     sdk: flutter