TF-2510 Validate outside & inline attachment

Signed-off-by: dab246 <tdvu@linagora.com>

model/lib/email/attachment.dart

@@ -11,6 +11,7 @@ class Attachment with EquatableMixin {
 
   static const String eventICSSubtype = 'ics';
   static const String eventCalendarSubtype = 'calendar';
+  static const String applicationRTFType = 'application/rtf';
 
   final PartId? partId;
   final Id? blobId;
@@ -34,7 +35,13 @@ class Attachment with EquatableMixin {
 
   bool hasCid() => cid != null && cid?.isNotEmpty == true;
 
-  bool isInlined() => disposition == ContentDisposition.inline;
+  bool isDispositionInlined() => disposition == ContentDisposition.inline;
+
+  bool isDispositionAttachment() => disposition == ContentDisposition.attachment;
+
+  bool isDispositionAttachmentNoCID() => isDispositionAttachment() && noCid();
+
+  bool isApplicationRTFInlined() => type?.mimeType == applicationRTFType && isDispositionInlined();
 
   String getDownloadUrl(String baseDownloadUrl, AccountId accountId) {
     final downloadUriTemplate = UriTemplate(baseDownloadUrl);

model/lib/extensions/attachment_extension.dart

@@ -27,4 +27,10 @@ extension AttachmentExtension on Attachment {
         disposition: disposition ?? this.disposition
     );
   }
+
+  bool isOutsideAttachment(List<Attachment> htmlBodyAttachments) {
+    return (isDispositionAttachmentNoCID() || !isDispositionInlined()) &&
+      !isApplicationRTFInlined() &&
+      !htmlBodyAttachments.include(this);
+  }
 }

model/lib/extensions/list_attachment_extension.dart

@@ -2,6 +2,7 @@
 import 'package:collection/collection.dart';
 import 'package:jmap_dart_client/jmap/account_id.dart';
 import 'package:model/email/attachment.dart';
+import 'package:model/extensions/attachment_extension.dart';
 
 extension ListAttachmentExtension on List<Attachment> {
 
@@ -14,21 +15,18 @@ extension ListAttachmentExtension on List<Attachment> {
     return 0;
   }
 
-  List<Attachment> getListAttachmentsDisplayedOutside(List<Attachment>? htmlBodyAttachments) {
-    return where((attachment) => _validateOutsideAttachment(attachment, htmlBodyAttachments)).toList();
+  List<Attachment> getListAttachmentsDisplayedOutside(List<Attachment> htmlBodyAttachments) {
+    return where((attachment) => attachment.isOutsideAttachment(htmlBodyAttachments)).toList();
   }
 
-  bool _validateOutsideAttachment(Attachment attachment, List<Attachment>? htmlBodyAttachments) {
-    final result = (attachment.noCid() || !attachment.isInlined()) && (htmlBodyAttachments == null || !htmlBodyAttachments._include(attachment));
-    return result;
-  }
-
-  bool _include(Attachment newAttachment) {
+  bool include(Attachment newAttachment) {
     final matchedAttachment = firstWhereOrNull((attachment) => attachment.blobId == newAttachment.blobId);
     return matchedAttachment != null;
   }
 
-  List<Attachment> get listAttachmentsDisplayedInContent => where((attachment) => attachment.hasCid()).toList();
+  List<Attachment> get listAttachmentsDisplayedInContent =>
+    where((attachment) => attachment.hasCid() && attachment.isDispositionInlined())
+    .toList();
 
   Map<String, String> toMapCidImageDownloadUrl({
     required AccountId accountId,