From 6ee5d55e73eb82523b95dbade98c17f6a636247d Mon Sep 17 00:00:00 2001
From: RadRussianRus <radrussianrus@gmail.com>
Date: Sun, 11 Sep 2022 04:43:46 +0300
Subject: [PATCH] [Improvement] Convert tg://user?id=<userid> to mentions if
 possible

---
 .../SourceFiles/api/api_text_entities.cpp     | 40 ++++++++++++++++++-
 1 file changed, 39 insertions(+), 1 deletion(-)

diff --git a/Telegram/SourceFiles/api/api_text_entities.cpp b/Telegram/SourceFiles/api/api_text_entities.cpp
index a782d6153..abe8b066a 100644
--- a/Telegram/SourceFiles/api/api_text_entities.cpp
+++ b/Telegram/SourceFiles/api/api_text_entities.cpp
@@ -13,6 +13,8 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_session.h"
 #include "data/data_document.h"
 #include "data/data_user.h"
+#include "base/qthelp_regex.h"
+#include "base/qthelp_url.h"
 
 namespace Api {
 namespace {
@@ -155,7 +157,43 @@ MTPVector<MTPMessageEntity> EntitiesToMTP(
 		auto length = MTP_int(entity.length());
 		switch (entity.type()) {
 		case EntityType::Url: v.push_back(MTP_messageEntityUrl(offset, length)); break;
-		case EntityType::CustomUrl: v.push_back(MTP_messageEntityTextUrl(offset, length, MTP_string(entity.data()))); break;
+		case EntityType::CustomUrl: {
+			auto url = entity.data();
+			auto inputUser = [&](const QString &data) -> MTPInputUser {
+				const auto trimmed = url.trimmed();
+				if (trimmed.isEmpty()) {
+					return MTP_inputUserEmpty();
+				}
+				auto regex = QRegularExpression(
+					QString::fromUtf8("^(?i)tg://user\\?(.+)"),
+					QRegularExpression::UseUnicodePropertiesOption);
+				regex.optimize();
+				const auto match = regex.match(trimmed);
+				if (!match.hasMatch() || match.capturedStart() != 0) {
+					return MTP_inputUserEmpty();
+				}
+				const auto parsed = qthelp::url_parse_params(match.captured(1), qthelp::UrlParamNameTransform::ToLower);
+				const auto qstr_uid = parsed.value("id");
+				if (qstr_uid.isEmpty()) {
+					return MTP_inputUserEmpty();
+				}
+				bool success;
+				UserId uid = qstr_uid.toLongLong(&success);
+				if (success && session) {
+					if (uid == session->userId()) {
+						return MTP_inputUserSelf();
+					} else if (const auto user = session->data().userLoaded(uid)) {
+						return MTP_inputUser(MTP_long(uid.bare), MTP_long(user->accessHash()));
+					}
+				}
+				return MTP_inputUserEmpty();
+			}(url);
+			if (inputUser.type() != mtpc_inputUserEmpty) {
+				v.push_back(MTP_inputMessageEntityMentionName(offset, length, inputUser));
+			} else {
+				v.push_back(MTP_messageEntityTextUrl(offset, length, MTP_string(url)));
+			}
+		} break;
 		case EntityType::Email: v.push_back(MTP_messageEntityEmail(offset, length)); break;
 		case EntityType::Hashtag: v.push_back(MTP_messageEntityHashtag(offset, length)); break;
 		case EntityType::Cashtag: v.push_back(MTP_messageEntityCashtag(offset, length)); break;