TF-3416 Handle download attachment in EML previewer on mobile

core/lib/data/constants/constant.dart

@@ -10,4 +10,7 @@ class Constant {
   static const textVCardMimeType = 'text/x-vcard';
   static const textPlainMimeType = 'text/plain';
   static const emlMimeType = 'message/rfc822';
+  static const mailtoScheme = 'mailto';
+  static const attachmentScheme = 'attachment';
+  static const emlPreviewerScheme = 'eml-previewer';
 }

core/lib/presentation/views/html_viewer/html_content_viewer_widget.dart

@@ -1,12 +1,12 @@
 import 'dart:async';
 import 'dart:math' as math;
 
+import 'package:core/data/constants/constant.dart';
 import 'package:core/presentation/views/loading/cupertino_loading_widget.dart';
 import 'package:core/utils/app_logger.dart';
 import 'package:core/utils/html/html_interaction.dart';
 import 'package:core/utils/html/html_utils.dart';
 import 'package:core/utils/platform_info.dart';
-import 'package:core/utils/preview_eml_file_utils.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
@@ -18,6 +18,7 @@ typedef OnScrollHorizontalEndAction = Function(bool leftDirection);
 typedef OnLoadWidthHtmlViewerAction = Function(bool isScrollPageViewActivated);
 typedef OnMailtoDelegateAction = Future<void> Function(Uri? uri);
 typedef OnPreviewEMLDelegateAction = Future<void> Function(Uri? uri);
+typedef OnDownloadAttachmentDelegateAction = Future<void> Function(Uri? uri);
 
 class HtmlContentViewer extends StatefulWidget {
 
@@ -29,6 +30,7 @@ class HtmlContentViewer extends StatefulWidget {
   final OnMailtoDelegateAction? onMailtoDelegateAction;
   final OnScrollHorizontalEndAction? onScrollHorizontalEnd;
   final OnPreviewEMLDelegateAction? onPreviewEMLDelegateAction;
+  final OnDownloadAttachmentDelegateAction? onDownloadAttachmentDelegateAction;
 
   const HtmlContentViewer({
     Key? key,
@@ -39,6 +41,7 @@ class HtmlContentViewer extends StatefulWidget {
     this.onMailtoDelegateAction,
     this.onScrollHorizontalEnd,
     this.onPreviewEMLDelegateAction,
+    this.onDownloadAttachmentDelegateAction,
   }) : super(key: key);
 
   @override
@@ -261,17 +264,23 @@ class _HtmlContentViewState extends State<HtmlContentViewer> {
 
     final requestUri = Uri.parse(url);
     if (widget.onMailtoDelegateAction != null &&
-        requestUri.isScheme('mailto')) {
+        requestUri.isScheme(Constant.mailtoScheme)) {
       await widget.onMailtoDelegateAction?.call(requestUri);
       return NavigationActionPolicy.CANCEL;
     }
 
     if (widget.onPreviewEMLDelegateAction != null &&
-        requestUri.isScheme(PreviewEmlFileUtils.emlPreviewerScheme)) {
+        requestUri.isScheme(Constant.emlPreviewerScheme)) {
       await widget.onPreviewEMLDelegateAction?.call(requestUri);
       return NavigationActionPolicy.CANCEL;
     }
 
+    if (widget.onDownloadAttachmentDelegateAction != null &&
+        requestUri.isScheme(Constant.attachmentScheme)) {
+      await widget.onDownloadAttachmentDelegateAction?.call(requestUri);
+      return NavigationActionPolicy.CANCEL;
+    }
+
     if (await launcher.canLaunchUrl(Uri.parse(url))) {
       await launcher.launchUrl(
         Uri.parse(url),

core/lib/utils/preview_eml_file_utils.dart

@@ -7,8 +7,6 @@ import 'package:html/dom.dart';
 import 'package:html/parser.dart';
 
 class PreviewEmlFileUtils {
-  static const String emlPreviewerScheme = 'eml-previewer';
-
   Element? _createEmailElement({
     required String subjectPrefix,
     required String fromPrefix,

lib/features/email/data/datasource_impl/email_datasource_impl.dart

@@ -42,8 +42,6 @@ import 'package:tmail_ui_user/features/mailbox/domain/model/create_new_mailbox_r
 import 'package:tmail_ui_user/features/sending_queue/domain/model/sending_email.dart';
 import 'package:tmail_ui_user/main/exceptions/exception_thrower.dart';
 import 'package:tmail_ui_user/main/exceptions/send_email_exception_thrower.dart';
-import 'package:tmail_ui_user/main/routes/app_routes.dart';
-import 'package:tmail_ui_user/main/routes/route_utils.dart';
 
 class EmailDataSourceImpl extends EmailDataSource {
 
@@ -452,15 +450,11 @@ class EmailDataSourceImpl extends EmailDataSource {
           final iconBase64Data = await _fileUtils.convertImageAssetToBase64(
             attachment.getIcon(_imagePaths));
 
-          final link = attachment.isEMLFile
-            ? _generateEMLAttachmentLink(attachment.blobId?.value)
-            : null;
-
           final previewAttachment = PreviewAttachment(
             iconBase64Data: iconBase64Data,
             name: attachment.name.escapeLtGtHtmlString(),
             size: filesize(attachment.size?.value),
-            link: link,
+            link: attachment.hyperLink,
           );
 
           listPreviewAttachment.add(previewAttachment);
@@ -498,21 +492,6 @@ class EmailDataSourceImpl extends EmailDataSource {
     }).catchError(_exceptionThrower.throwException);
   }
 
-  String _generateEMLAttachmentLink(String? blobId) {
-    if (blobId == null) return '';
-
-    if (PlatformInfo.isWeb) {
-      return RouteUtils.createUrlWebLocationBar(
-        AppRoutes.emailEMLPreviewer,
-        previewId: blobId,
-      ).toString();
-    } else if (PlatformInfo.isMobile) {
-      return '${PreviewEmlFileUtils.emlPreviewerScheme}://$blobId';
-    } else {
-      return '';
-    }
-  }
-
   Future<String> _transformEmailContent(
     List<EmailContent> emailContents,
     Map<String, String> mapCidImageDownloadUrl,

lib/features/email/presentation/controller/single_email_controller.dart

@@ -2059,6 +2059,8 @@ class SingleEmailController extends BaseController with AppLoaderMixin {
             emlPreviewer: emlPreviewer,
             onMailtoDelegateAction: openMailToLink,
             onPreviewEMLDelegateAction: (uri) => _openEMLPreviewer(context, uri),
+            onDownloadAttachmentDelegateAction: (uri) =>
+                _downloadAttachmentInEMLPreview(context, uri),
           ),
         );
       },
@@ -2069,13 +2071,23 @@ class SingleEmailController extends BaseController with AppLoaderMixin {
     log('SingleEmailController::_openEMLPreviewer:uri = $uri');
     if (uri == null) return;
 
-    final blobId = uri.authority;
+    final blobId = uri.path;
     log('SingleEmailController::_openEMLPreviewer:blobId = $blobId');
     if (blobId.isEmpty) return;
 
     previewEMLFileAction(Id(blobId), AppLocalizations.of(context));
   }
 
+  Future<void> _downloadAttachmentInEMLPreview(BuildContext context, Uri? uri) async {
+    log('SingleEmailController::_downloadAttachmentInEMLPreview:uri = $uri');
+    if (uri == null) return;
+
+    final attachment = EmailUtils.parsingAttachmentByUri(uri);
+    if (attachment == null) return;
+
+    handleDownloadAttachmentAction(context, attachment);
+  }
+
   void handleMailToAttendees(CalendarOrganizer? organizer, List<CalendarAttendee>? attendees) {
     final listEmailAddressAttendees = attendees
       ?.map((attendee) => EmailAddress(attendee.name?.name, attendee.mailto?.mailAddress.value))

lib/features/email/presentation/extensions/attachment_extension.dart

@@ -1,6 +1,10 @@
+import 'package:core/data/constants/constant.dart';
 import 'package:core/presentation/extensions/media_type_extension.dart';
 import 'package:core/presentation/resources/image_paths.dart';
+import 'package:core/utils/platform_info.dart';
 import 'package:model/email/attachment.dart';
+import 'package:tmail_ui_user/main/routes/app_routes.dart';
+import 'package:tmail_ui_user/main/routes/route_utils.dart';
 
 extension AttachmentExtension on Attachment {
   String getIcon(ImagePaths imagePaths) => type?.getIcon(imagePaths, fileName: name) ?? imagePaths.icFileEPup;
@@ -8,4 +12,27 @@ extension AttachmentExtension on Attachment {
   bool get isPDFFile => type?.isPDFFile(fileName: name) ?? false;
 
   bool get isEMLFile => type?.isEMLFile ?? false;
+
+  String get hyperLink => isEMLFile ? emlLink : attachmentLink;
+
+  String get emlLink {
+    if (blobId == null) return '';
+
+    if (PlatformInfo.isWeb) {
+      return RouteUtils.createUrlWebLocationBar(
+        AppRoutes.emailEMLPreviewer,
+        previewId: blobId!.value,
+      ).toString();
+    } else if (PlatformInfo.isMobile) {
+      return '${Constant.emlPreviewerScheme}:${blobId!.value}';
+    } else {
+      return '';
+    }
+  }
+
+  String get attachmentLink {
+    if (blobId == null) return '';
+
+    return '${Constant.attachmentScheme}:${blobId!.value}?name=${name ?? ''}&size=${size?.value ?? ''}&type=${type?.mimeType ?? ''}';
+  }
 }

lib/features/email/presentation/utils/email_utils.dart

@@ -5,11 +5,15 @@ import 'package:core/utils/app_logger.dart';
 import 'package:core/utils/mail/mail_address.dart';
 import 'package:get/get_utils/src/get_utils/get_utils.dart';
 import 'package:dartz/dartz.dart';
+import 'package:http_parser/http_parser.dart';
 import 'package:jmap_dart_client/jmap/account_id.dart';
 import 'package:jmap_dart_client/jmap/core/capability/capability_identifier.dart';
+import 'package:jmap_dart_client/jmap/core/id.dart';
 import 'package:jmap_dart_client/jmap/core/properties/properties.dart';
 import 'package:jmap_dart_client/jmap/core/session/session.dart';
+import 'package:jmap_dart_client/jmap/core/unsigned_int.dart';
 import 'package:jmap_dart_client/jmap/mail/email/email_address.dart';
+import 'package:model/email/attachment.dart';
 import 'package:tmail_ui_user/features/email/domain/state/download_attachment_for_web_state.dart';
 import 'package:tmail_ui_user/features/email/presentation/model/email_unsubscribe.dart';
 import 'package:tmail_ui_user/features/thread/domain/constants/thread_constants.dart';
@@ -190,4 +194,24 @@ class EmailUtils {
     final mailtoLinks = extractMailtoLinksFromListPost(listPost);
     return extractRecipientsFromListMailtoLink(mailtoLinks);
   }
+
+  static Attachment? parsingAttachmentByUri(Uri uri) {
+    try {
+      final blobId = uri.path;
+      final queryParams = uri.queryParameters;
+      final name = queryParams['name'];
+      final size = queryParams['size'];
+      final type = queryParams['type'];
+      log('EmailUtils::parsingAttachmentByUri:blobId = $blobId | name = $name | size = $size | type = $type');
+      return Attachment(
+        blobId: Id(blobId),
+        name: name,
+        size: size?.isNotEmpty == true ? UnsignedInt(int.parse(size!)) : null,
+        type: type?.isNotEmpty == true ? MediaType.parse(type!) : null,
+      );
+    } catch (e) {
+      logError('EmailUtils::parsingAttachmentByUri:Exception = $e:');
+      return null;
+    }
+  }
 }

lib/features/email_previewer/email_previewer_dialog_view.dart

@@ -10,12 +10,14 @@ class EmailPreviewerDialogView extends StatelessWidget {
   final EMLPreviewer emlPreviewer;
   final OnMailtoDelegateAction onMailtoDelegateAction;
   final OnPreviewEMLDelegateAction onPreviewEMLDelegateAction;
+  final OnDownloadAttachmentDelegateAction onDownloadAttachmentDelegateAction;
 
   const EmailPreviewerDialogView({
     super.key,
     required this.emlPreviewer,
     required this.onMailtoDelegateAction,
     required this.onPreviewEMLDelegateAction,
+    required this.onDownloadAttachmentDelegateAction,
   });
 
   @override
@@ -29,6 +31,7 @@ class EmailPreviewerDialogView extends StatelessWidget {
           direction: AppUtils.getCurrentDirection(context),
           onMailtoDelegateAction: onMailtoDelegateAction,
           onPreviewEMLDelegateAction: onPreviewEMLDelegateAction,
+          onDownloadAttachmentDelegateAction: onDownloadAttachmentDelegateAction,
         ),
       ),
     );

test/features/email/parsing_attachment_by_uri_test.dart

@@ -0,0 +1,63 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:tmail_ui_user/features/email/presentation/utils/email_utils.dart';
+
+void main() {
+  group('parsingAttachmentByUri', () {
+    test('should parse a valid URI and return an Attachment object', () {
+      final uri = Uri.parse(
+        'attachment:blobId?name=testfile.txt&size=1024&type=text/plain',
+      );
+
+      final attachment = EmailUtils.parsingAttachmentByUri(uri);
+
+      expect(attachment, isNotNull);
+      expect(attachment!.blobId?.value, 'blobId');
+      expect(attachment.name, 'testfile.txt');
+      expect(attachment.size?.value, 1024);
+      expect(attachment.type?.toString(), 'text/plain');
+    });
+
+    test('should return null for an invalid URI', () {
+      final uri = Uri.parse('https://example.com');
+
+      final attachment = EmailUtils.parsingAttachmentByUri(uri);
+
+      expect(attachment, isNull);
+    });
+
+    test('should handle missing optional parameters gracefully', () {
+      final uri = Uri.parse('attachment:blobId?name=testfile.txt');
+
+      final attachment = EmailUtils.parsingAttachmentByUri(uri);
+
+      expect(attachment, isNotNull);
+      expect(attachment!.blobId?.value, 'blobId');
+      expect(attachment.name, 'testfile.txt');
+      expect(attachment.size, isNull);
+      expect(attachment.type, isNull);
+    });
+
+    test('should handle invalid size parameter gracefully', () {
+      final uri = Uri.parse(
+        'attachment:blobId?name=testfile.txt&size=invalid',
+      );
+
+      final attachment = EmailUtils.parsingAttachmentByUri(uri);
+
+      expect(attachment, isNull);
+    });
+
+    test('should handle empty type parameter gracefully', () {
+      final uri = Uri.parse(
+        'attachment:blobId?name=testfile.txt&type=',
+      );
+
+      final attachment = EmailUtils.parsingAttachmentByUri(uri);
+
+      expect(attachment, isNotNull);
+      expect(attachment!.blobId?.value, 'blobId');
+      expect(attachment.name, 'testfile.txt');
+      expect(attachment.type, isNull);
+    });
+  });
+}