Add synchronous td_api::getCountryFlagEmoji.

td/generate/scheme/td_api.tl

@@ -3978,7 +3978,7 @@ availableReaction type:ReactionType needs_premium:Bool = AvailableReaction;
 //@allow_custom_emoji True, if any custom emoji reaction can be added by Telegram Premium subscribers
 availableReactions top_reactions:vector<availableReaction> recent_reactions:vector<availableReaction> popular_reactions:vector<availableReaction> allow_custom_emoji:Bool = AvailableReactions;
 
-//@description Contains information about a emoji reaction
+//@description Contains information about an emoji reaction
 //@emoji Text representation of the reaction
 //@title Reaction title
 //@is_active True, if the reaction can be added to new messages and enabled in chats
@@ -7520,7 +7520,7 @@ setPinnedForumTopics chat_id:int53 message_thread_ids:vector<int53> = Ok;
 deleteForumTopic chat_id:int53 message_thread_id:int53 = Ok;
 
 
-//@description Returns information about a emoji reaction. Returns a 404 error if the reaction is not found @emoji Text representation of the reaction
+//@description Returns information about an emoji reaction. Returns a 404 error if the reaction is not found @emoji Text representation of the reaction
 getEmojiReaction emoji:string = EmojiReaction;
 
 //@description Returns TGS stickers with generic animations for custom emoji reactions
@@ -7587,6 +7587,9 @@ parseMarkdown text:formattedText = FormattedText;
 //@description Replaces text entities with Markdown formatting in a human-friendly format. Entities that can't be represented in Markdown unambiguously are kept as is. Can be called synchronously @text The text
 getMarkdownText text:formattedText = FormattedText;
 
+//@description Returns an emoji for the given country. Returns an empty string on failure. Can be called synchronously @country_code A two-letter ISO 3166-1 alpha-2 country code as received from getCountries
+getCountryFlagEmoji country_code:string = Text;
+
 //@description Returns the MIME type of a file, guessed by its extension. Returns an empty string on failure. Can be called synchronously @file_name The name of the file or path to the file
 getFileMimeType file_name:string = Text;
 

td/telegram/CountryInfoManager.cpp

@@ -577,6 +577,32 @@ const CountryInfoManager::CountryList *CountryInfoManager::get_country_list(Coun
   return country;
 }
 
+string CountryInfoManager::get_country_flag_emoji(const string &country_code) {
+  if (country_code.size() != 2 || !is_alpha(country_code[0]) || !is_alpha(country_code[1])) {
+    return string();
+  }
+  char first = to_upper(country_code[0]);
+  char second = to_upper(country_code[1]);
+  if (first == 'Y' && second == 'L') {
+    return string();
+  }
+  if (first == 'F' && second == 'T') {
+    return "\xF0\x9F\x8F\xB4\xE2\x80\x8D\xE2\x98\xA0\xEF\xB8\x8F";  // pirate flag
+  }
+  if (first == 'X' && second == 'G') {
+    return "\xF0\x9F\x9B\xB0";  // satellite
+  }
+  if (first == 'X' && second == 'V') {
+    return "\xF0\x9F\x8C\x8D";  // globe showing Europe-Africa
+  }
+  string result;
+  result.reserve(8);
+  append_utf8_character(result, 0x1F1A5 + first);
+  append_utf8_character(result, 0x1F1A5 + second);
+  CHECK(result.size() == 8);
+  return result;
+}
+
 int32 CountryInfoManager::manager_count_ = 0;
 std::mutex CountryInfoManager::country_mutex_;
 FlatHashMap<string, unique_ptr<CountryInfoManager::CountryList>> CountryInfoManager::countries_;

td/telegram/CountryInfoManager.h

@@ -37,6 +37,8 @@ class CountryInfoManager final : public Actor {
   static td_api::object_ptr<td_api::phoneNumberInfo> get_phone_number_info_sync(const string &language_code,
                                                                                 string phone_number_prefix);
 
+  static string get_country_flag_emoji(const string &country_code);
+
   void on_update_fragment_prefixes();
 
   CountryInfoManager(const CountryInfoManager &) = delete;

td/telegram/Td.cpp

@@ -2740,6 +2740,7 @@ bool Td::is_synchronous_request(const td_api::Function *function) {
     case td_api::parseMarkdown::ID:
     case td_api::getMarkdownText::ID:
     case td_api::searchStringsByPrefix::ID:
+    case td_api::getCountryFlagEmoji::ID:
     case td_api::getFileMimeType::ID:
     case td_api::getFileExtension::ID:
     case td_api::cleanFileName::ID:
@@ -2980,6 +2981,7 @@ td_api::object_ptr<td_api::Object> Td::static_request(td_api::object_ptr<td_api:
       case td_api::parseMarkdown::ID:
       case td_api::getMarkdownText::ID:
       case td_api::searchStringsByPrefix::ID:
+      case td_api::getCountryFlagEmoji::ID:
       case td_api::getFileMimeType::ID:
       case td_api::getFileExtension::ID:
       case td_api::cleanFileName::ID:
@@ -9042,6 +9044,10 @@ void Td::on_request(uint64 id, const td_api::searchStringsByPrefix &request) {
   UNREACHABLE();
 }
 
+void Td::on_request(uint64 id, const td_api::getCountryFlagEmoji &request) {
+  UNREACHABLE();
+}
+
 void Td::on_request(uint64 id, const td_api::getFileMimeType &request) {
   UNREACHABLE();
 }
@@ -9246,6 +9252,11 @@ td_api::object_ptr<td_api::Object> Td::do_static_request(td_api::searchStringsBy
   return td_api::make_object<td_api::foundPositions>(total_count, std::move(result));
 }
 
+td_api::object_ptr<td_api::Object> Td::do_static_request(const td_api::getCountryFlagEmoji &request) {
+  // don't check country code UTF-8 correctness
+  return td_api::make_object<td_api::text>(CountryInfoManager::get_country_flag_emoji(request.country_code_));
+}
+
 td_api::object_ptr<td_api::Object> Td::do_static_request(const td_api::getFileMimeType &request) {
   // don't check file name UTF-8 correctness
   return make_tl_object<td_api::text>(MimeType::from_extension(PathView(request.file_name_).extension()));

td/telegram/Td.h

@@ -1731,6 +1731,8 @@ class Td final : public Actor {
 
   void on_request(uint64 id, const td_api::searchStringsByPrefix &request);
 
+  void on_request(uint64 id, const td_api::getCountryFlagEmoji &request);
+
   void on_request(uint64 id, const td_api::getFileMimeType &request);
 
   void on_request(uint64 id, const td_api::getFileExtension &request);
@@ -1793,6 +1795,7 @@ class Td final : public Actor {
   static td_api::object_ptr<td_api::Object> do_static_request(td_api::parseMarkdown &request);
   static td_api::object_ptr<td_api::Object> do_static_request(td_api::getMarkdownText &request);
   static td_api::object_ptr<td_api::Object> do_static_request(td_api::searchStringsByPrefix &request);
+  static td_api::object_ptr<td_api::Object> do_static_request(const td_api::getCountryFlagEmoji &request);
   static td_api::object_ptr<td_api::Object> do_static_request(const td_api::getFileMimeType &request);
   static td_api::object_ptr<td_api::Object> do_static_request(const td_api::getFileExtension &request);
   static td_api::object_ptr<td_api::Object> do_static_request(const td_api::cleanFileName &request);

td/telegram/cli.cpp

@@ -4133,6 +4133,8 @@ class CliClient final : public Actor {
       get_args(args, strings, query, limit, return_none_for_empty_query);
       execute(td_api::make_object<td_api::searchStringsByPrefix>(autosplit_str(strings), query, as_limit(limit),
                                                                  return_none_for_empty_query));
+    } else if (op == "gcfe") {
+      execute(td_api::make_object<td_api::getCountryFlagEmoji>(trim(args)));
     } else if (op == "gfmt") {
       execute(td_api::make_object<td_api::getFileMimeType>(trim(args)));
     } else if (op == "gfe") {