Add getMessageFileType method.

td/generate/scheme/td_api.tl

@@ -2615,6 +2615,18 @@ checkChatUsernameResultPublicChatsTooMuch = CheckChatUsernameResult;
 checkChatUsernameResultPublicGroupsUnavailable = CheckChatUsernameResult;
 
 
+//@class MessageFileType @description Contains information about a file with messages exported from another app
+
+//@description The messages was exported from a private chat
+messageFileTypePrivate = MessageFileType;
+
+//@description The messages was exported from a group chat @title Title of the group chat
+messageFileTypeGroup title:string = MessageFileType;
+
+//@description The messages was exported from a chat of unknown type
+messageFileTypeUnknown = MessageFileType;
+
+
 //@class PushMessageContent @description Contains content of a push message notification
 
 //@description A general message with hidden content @is_pinned True, if the message is a pinned message with the specified content
@@ -4388,6 +4400,9 @@ readFilePart file_id:int32 offset:int32 count:int32 = FilePart;
 deleteFile file_id:int32 = Ok;
 
 
+//@description Returns information about a file with messages exported from another app @message_file_head Beginning of the message file; up to 100 first lines
+getMessageFileType message_file_head:string = MessageFileType;
+
 //@description Imports messages exported from another app
 //@chat_id Identifier of a chat to which the messages will be imported. It must be an identifier of a private chat with a mutual contact or an identifier of a created supergroup chat
 //@message_file File with messages to import. Only inputFileLocal and inputFileGenerated are supported. The file must not be previously uploaded

td/telegram/MessagesManager.cpp

@@ -1009,6 +1009,43 @@ class CreateChannelQuery : public Td::ResultHandler {
   }
 };
 
+class CheckHistoryImportQuery : public Td::ResultHandler {
+  Promise<tl_object_ptr<td_api::MessageFileType>> promise_;
+
+ public:
+  explicit CheckHistoryImportQuery(Promise<tl_object_ptr<td_api::MessageFileType>> &&promise)
+      : promise_(std::move(promise)) {
+  }
+
+  void send(const string &message_file_head) {
+    send_query(G()->net_query_creator().create(telegram_api::messages_checkHistoryImport(message_file_head)));
+  }
+
+  void on_result(uint64 id, BufferSlice packet) override {
+    auto result_ptr = fetch_result<telegram_api::messages_checkHistoryImport>(packet);
+    if (result_ptr.is_error()) {
+      return on_error(id, result_ptr.move_as_error());
+    }
+
+    auto ptr = result_ptr.move_as_ok();
+    LOG(INFO) << "Receive result for CheckHistoryImportQuery: " << to_string(ptr);
+    auto file_type = [&]() -> td_api::object_ptr<td_api::MessageFileType> {
+      if (ptr->pm_) {
+        return td_api::make_object<td_api::messageFileTypePrivate>();
+      } else if (ptr->group_) {
+        return td_api::make_object<td_api::messageFileTypeGroup>(ptr->title_);
+      } else {
+        return td_api::make_object<td_api::messageFileTypeUnknown>();
+      }
+    }();
+    promise_.set_value(std::move(file_type));
+  }
+
+  void on_error(uint64 id, Status status) override {
+    promise_.set_error(std::move(status));
+  }
+};
+
 class InitHistoryImportQuery : public Td::ResultHandler {
   Promise<Unit> promise_;
   FileId file_id_;
@@ -26405,6 +26442,11 @@ Result<MessageId> MessagesManager::add_local_message(
   return message_id;
 }
 
+void MessagesManager::get_message_file_type(const string &message_file_head,
+                                            Promise<td_api::object_ptr<td_api::MessageFileType>> &&promise) {
+  td_->create_handler<CheckHistoryImportQuery>(std::move(promise))->send(message_file_head);
+}
+
 void MessagesManager::import_messages(DialogId dialog_id, const td_api::object_ptr<td_api::InputFile> &message_file,
                                       const vector<td_api::object_ptr<td_api::InputFile>> &attached_files,
                                       Promise<Unit> &&promise) {

td/telegram/MessagesManager.h

@@ -394,6 +394,9 @@ class MessagesManager : public Actor {
                                       tl_object_ptr<td_api::InputMessageContent> &&input_message_content)
       TD_WARN_UNUSED_RESULT;
 
+  void get_message_file_type(const string &message_file_head,
+                             Promise<td_api::object_ptr<td_api::MessageFileType>> &&promise);
+
   void import_messages(DialogId dialog_id, const td_api::object_ptr<td_api::InputFile> &message_file,
                        const vector<td_api::object_ptr<td_api::InputFile>> &attached_files, Promise<Unit> &&promise);
 

td/telegram/Td.cpp

@@ -6535,6 +6535,13 @@ void Td::on_request(uint64 id, const td_api::deleteFile &request) {
                "td_api::deleteFile");
 }
 
+void Td::on_request(uint64 id, td_api::getMessageFileType &request) {
+  CHECK_IS_USER();
+  CLEAN_INPUT_STRING(request.message_file_head_);
+  CREATE_REQUEST_PROMISE();
+  messages_manager_->get_message_file_type(request.message_file_head_, std::move(promise));
+}
+
 void Td::on_request(uint64 id, const td_api::importMessages &request) {
   CHECK_IS_USER();
   CREATE_OK_REQUEST_PROMISE();

td/telegram/Td.h

@@ -836,6 +836,8 @@ class Td final : public NetQueryCallback {
 
   void on_request(uint64 id, const td_api::deleteFile &request);
 
+  void on_request(uint64 id, td_api::getMessageFileType &request);
+
   void on_request(uint64 id, const td_api::importMessages &request);
 
   void on_request(uint64 id, const td_api::blockMessageSenderFromReplies &request);

td/telegram/cli.cpp

@@ -24,6 +24,7 @@
 #include "td/utils/crypto.h"
 #include "td/utils/ExitGuard.h"
 #include "td/utils/FileLog.h"
+#include "td/utils/filesystem.h"
 #include "td/utils/format.h"
 #include "td/utils/JsonBuilder.h"
 #include "td/utils/logging.h"
@@ -41,6 +42,7 @@
 #include "td/utils/Status.h"
 #include "td/utils/StringBuilder.h"
 #include "td/utils/Time.h"
+#include "td/utils/utf8.h"
 
 #ifndef USE_READLINE
 #include "td/utils/find_boundary.h"
@@ -2971,6 +2973,17 @@ class CliClient final : public Actor {
                 as_input_file(document), nullptr, true, as_caption(""));
             return content;
           })));
+    } else if (op == "gmft") {
+      auto r_message_file_head = read_file_str(args, 2 << 10);
+      if (r_message_file_head.is_error()) {
+        LOG(ERROR) << r_message_file_head.error();
+      } else {
+        auto message_file_head = r_message_file_head.move_as_ok();
+        while (!check_utf8(message_file_head)) {
+          message_file_head.pop_back();
+        }
+        send_request(td_api::make_object<td_api::getMessageFileType>(message_file_head));
+      }
     } else if (op == "im") {
       string chat_id;
       string message_file;