Make canSendMessageToUser response strongly typed.

td/generate/scheme/td_api.tl

@@ -5403,6 +5403,18 @@ readDatePrivacySettings show_read_date:Bool = ReadDatePrivacySettings;
 newChatPrivacySettings allow_new_chats_from_unknown_users:Bool = NewChatPrivacySettings;
 
 
+//@class CanSendMessageToUserResult @description Describes result of canSendMessageToUser
+
+//@description The user can be messaged
+canSendMessageToUserResultOk = CanSendMessageToUserResult;
+
+//@description The user can't be messaged, because they are deleted or unknown
+canSendMessageToUserResultUserIsDeleted = CanSendMessageToUserResult;
+
+//@description The user can't be messaged, because they restrict new chats with non-contacts
+canSendMessageToUserResultUserRestrictsNewChats = CanSendMessageToUserResult;
+
+
 //@description Contains information about the period of inactivity after which the current user's account will automatically be deleted @days Number of days of inactivity before the account will be flagged for deletion; 30-366 days
 accountTtl days:int32 = AccountTtl;
 
@@ -9526,7 +9538,7 @@ getNewChatPrivacySettings = NewChatPrivacySettings;
 
 
 //@description Check whether the current user can message another user or try to create a chat with them @user_id Identifier of the other user
-canSendMessageToUser user_id:int53 = Ok;
+canSendMessageToUser user_id:int53 = CanSendMessageToUserResult;
 
 
 //@description Returns the value of an option by its name. (Check the list of available options on https://core.telegram.org/tdlib/options.) Can be called before authorization. Can be called synchronously for options "version" and "commit_hash"

td/telegram/ContactsManager.cpp

@@ -5528,38 +5528,39 @@ int32 ContactsManager::get_user_was_online(const User *u, UserId user_id, int32
   return was_online;
 }
 
-void ContactsManager::can_send_message_to_user(UserId user_id, bool force, Promise<Unit> &&promise) {
+void ContactsManager::can_send_message_to_user(
+    UserId user_id, bool force, Promise<td_api::object_ptr<td_api::CanSendMessageToUserResult>> &&promise) {
   TRY_STATUS_PROMISE(promise, G()->close_status());
   if (user_id == get_my_id()) {
-    return promise.set_value(Unit());
+    return promise.set_value(td_api::make_object<td_api::canSendMessageToUserResultOk>());
   }
   const auto *u = get_user(user_id);
   if (!have_input_peer_user(u, user_id, AccessRights::Write)) {
-    return promise.set_error(Status::Error(400, "Have no write access to the chat"));
+    return promise.set_value(td_api::make_object<td_api::canSendMessageToUserResultUserIsDeleted>());
   }
   if (!u->contact_require_premium || td_->option_manager_->get_option_boolean("is_premium") || u->is_mutual_contact) {
-    return promise.set_value(Unit());
+    return promise.set_value(td_api::make_object<td_api::canSendMessageToUserResultOk>());
   }
 
   auto user_full = get_user_full_force(user_id, "can_send_message_to_user");
   if (user_full != nullptr) {
     if (!user_full->contact_require_premium) {
-      return promise.set_value(Unit());
+      return promise.set_value(td_api::make_object<td_api::canSendMessageToUserResultOk>());
     }
-    return promise.set_error(Status::Error(400, "Can't write to the user first"));
+    return promise.set_value(td_api::make_object<td_api::canSendMessageToUserResultUserRestrictsNewChats>());
   }
 
   auto it = user_full_contact_require_premium_.find(user_id);
   if (it != user_full_contact_require_premium_.end()) {
     if (!it->second) {
-      return promise.set_value(Unit());
+      return promise.set_value(td_api::make_object<td_api::canSendMessageToUserResultOk>());
     }
-    return promise.set_error(Status::Error(400, "Can't write to the user first"));
+    return promise.set_value(td_api::make_object<td_api::canSendMessageToUserResultUserRestrictsNewChats>());
   }
 
   if (force) {
     LOG(ERROR) << "Can't check " << user_id << " message privacy settings";
-    return promise.set_value(Unit());
+    return promise.set_value(td_api::make_object<td_api::canSendMessageToUserResultOk>());
   }
 
   auto query_promise = PromiseCreator::lambda(

td/telegram/ContactsManager.h

@@ -185,7 +185,8 @@ class ContactsManager final : public Actor {
   int32 get_secret_chat_layer(SecretChatId secret_chat_id) const;
   FolderId get_secret_chat_initial_folder_id(SecretChatId secret_chat_id) const;
 
-  void can_send_message_to_user(UserId user_id, bool force, Promise<Unit> &&promise);
+  void can_send_message_to_user(UserId user_id, bool force,
+                                Promise<td_api::object_ptr<td_api::CanSendMessageToUserResult>> &&promise);
 
   void on_imported_contacts(int64 random_id, Result<tl_object_ptr<telegram_api::contacts_importedContacts>> result);
 

td/telegram/Td.cpp

@@ -6530,7 +6530,7 @@ void Td::on_request(uint64 id, td_api::setNewChatPrivacySettings &request) {
 
 void Td::on_request(uint64 id, const td_api::canSendMessageToUser &request) {
   CHECK_IS_USER();
-  CREATE_OK_REQUEST_PROMISE();
+  CREATE_REQUEST_PROMISE();
   contacts_manager_->can_send_message_to_user(UserId(request.user_id_), false, std::move(promise));
 }