From 3678343a0645c0b260bc8f90918197ae959062ed Mon Sep 17 00:00:00 2001
From: levlam <levlam@telegram.org>
Date: Mon, 27 Feb 2023 01:17:22 +0300
Subject: [PATCH] Simplify language code check.

---
 td/telegram/BotCommand.cpp | 25 +++----------------------
 td/telegram/misc.cpp       | 11 +++++++++++
 td/telegram/misc.h         |  4 ++++
 3 files changed, 18 insertions(+), 22 deletions(-)

diff --git a/td/telegram/BotCommand.cpp b/td/telegram/BotCommand.cpp
index 59ca71b64..0711f6ffb 100644
--- a/td/telegram/BotCommand.cpp
+++ b/td/telegram/BotCommand.cpp
@@ -141,23 +141,10 @@ bool operator==(const BotCommands &lhs, const BotCommands &rhs) {
   return lhs.bot_user_id_ == rhs.bot_user_id_ && lhs.commands_ == rhs.commands_;
 }
 
-static bool is_valid_language_code(const string &language_code) {
-  if (language_code.empty()) {
-    return true;
-  }
-  if (language_code.size() != 2) {
-    return false;
-  }
-  return 'a' <= language_code[0] && language_code[0] <= 'z' && 'a' <= language_code[1] && language_code[1] <= 'z';
-}
-
 void set_commands(Td *td, td_api::object_ptr<td_api::BotCommandScope> &&scope_ptr, string &&language_code,
                   vector<td_api::object_ptr<td_api::botCommand>> &&commands, Promise<Unit> &&promise) {
   TRY_RESULT_PROMISE(promise, scope, BotCommandScope::get_bot_command_scope(td, std::move(scope_ptr)));
-
-  if (!is_valid_language_code(language_code)) {
-    return promise.set_error(Status::Error(400, "Invalid language code specified"));
-  }
+  TRY_STATUS_PROMISE(promise, validate_bot_language_code(language_code));
 
   vector<BotCommand> new_commands;
   for (auto &command : commands) {
@@ -204,10 +191,7 @@ void set_commands(Td *td, td_api::object_ptr<td_api::BotCommandScope> &&scope_pt
 void delete_commands(Td *td, td_api::object_ptr<td_api::BotCommandScope> &&scope_ptr, string &&language_code,
                      Promise<Unit> &&promise) {
   TRY_RESULT_PROMISE(promise, scope, BotCommandScope::get_bot_command_scope(td, std::move(scope_ptr)));
-
-  if (!is_valid_language_code(language_code)) {
-    return promise.set_error(Status::Error(400, "Invalid language code specified"));
-  }
+  TRY_STATUS_PROMISE(promise, validate_bot_language_code(language_code));
 
   td->create_handler<ResetBotCommandsQuery>(std::move(promise))->send(scope, language_code);
 }
@@ -215,10 +199,7 @@ void delete_commands(Td *td, td_api::object_ptr<td_api::BotCommandScope> &&scope
 void get_commands(Td *td, td_api::object_ptr<td_api::BotCommandScope> &&scope_ptr, string &&language_code,
                   Promise<td_api::object_ptr<td_api::botCommands>> &&promise) {
   TRY_RESULT_PROMISE(promise, scope, BotCommandScope::get_bot_command_scope(td, std::move(scope_ptr)));
-
-  if (!is_valid_language_code(language_code)) {
-    return promise.set_error(Status::Error(400, "Invalid language code specified"));
-  }
+  TRY_STATUS_PROMISE(promise, validate_bot_language_code(language_code));
 
   td->create_handler<GetBotCommandsQuery>(std::move(promise))->send(scope, language_code);
 }
diff --git a/td/telegram/misc.cpp b/td/telegram/misc.cpp
index f8917a80d..800ef0a4c 100644
--- a/td/telegram/misc.cpp
+++ b/td/telegram/misc.cpp
@@ -340,4 +340,15 @@ bool check_currency_amount(int64 amount) {
   return -MAX_AMOUNT <= amount && amount <= MAX_AMOUNT;
 }
 
+Status validate_bot_language_code(const string &language_code) {
+  if (language_code.empty()) {
+    return Status::OK();
+  }
+  if (language_code.size() == 2 && 'a' <= language_code[0] && language_code[0] <= 'z' && 'a' <= language_code[1] &&
+      language_code[1] <= 'z') {
+    return Status::OK();
+  }
+  return Status::Error(400, "Invalid language code specified");
+}
+
 }  // namespace td
diff --git a/td/telegram/misc.h b/td/telegram/misc.h
index 611c6b9aa..37c91b76e 100644
--- a/td/telegram/misc.h
+++ b/td/telegram/misc.h
@@ -8,6 +8,7 @@
 
 #include "td/utils/common.h"
 #include "td/utils/Slice.h"
+#include "td/utils/Status.h"
 
 namespace td {
 
@@ -44,4 +45,7 @@ string get_emoji_fingerprint(uint64 num);
 // checks whether currency amount is valid
 bool check_currency_amount(int64 amount);
 
+// checks whether language code is valid for bot settings
+Status validate_bot_language_code(const string &language_code);
+
 }  // namespace td