From 1774b21e88a8f9f35cc0223a74e52fac672aa49f Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Thu, 21 Jan 2021 08:20:29 +0400
Subject: [PATCH] Add ability to completely delete legacy group.

---
 Telegram/SourceFiles/boxes/confirm_box.cpp               | 6 +++---
 .../SourceFiles/boxes/peers/edit_peer_invite_links.cpp   | 2 +-
 Telegram/SourceFiles/data/data_histories.cpp             | 9 ++++++++-
 Telegram/SourceFiles/data/data_peer.cpp                  | 2 ++
 4 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/Telegram/SourceFiles/boxes/confirm_box.cpp b/Telegram/SourceFiles/boxes/confirm_box.cpp
index e5b4f766da..224f7ec2c9 100644
--- a/Telegram/SourceFiles/boxes/confirm_box.cpp
+++ b/Telegram/SourceFiles/boxes/confirm_box.cpp
@@ -601,9 +601,7 @@ void DeleteMessagesBox::prepare() {
 			deleteText = _wipeHistoryPeer->isUser()
 				? tr::lng_box_delete()
 				: tr::lng_box_leave();
-			deleteStyle = &(peer->isChannel()
-				? st::defaultBoxButton
-				: st::attentionBoxButton);
+			deleteStyle = &st::attentionBoxButton;
 		}
 		if (auto revoke = revokeText(peer)) {
 			_revoke.create(this, revoke->checkbox, false, st::defaultBoxCheckbox);
@@ -702,6 +700,8 @@ auto DeleteMessagesBox::revokeText(not_null<PeerData*> peer) const
 				tr::now,
 				lt_user,
 				user->firstName);
+		} else if (_wipeHistoryJustClear) {
+			return std::nullopt;
 		} else {
 			result.checkbox = tr::lng_delete_for_everyone_check(tr::now);
 		}
diff --git a/Telegram/SourceFiles/boxes/peers/edit_peer_invite_links.cpp b/Telegram/SourceFiles/boxes/peers/edit_peer_invite_links.cpp
index 91d0751eca..4f8f08f5a5 100644
--- a/Telegram/SourceFiles/boxes/peers/edit_peer_invite_links.cpp
+++ b/Telegram/SourceFiles/boxes/peers/edit_peer_invite_links.cpp
@@ -748,7 +748,7 @@ void ManageInviteLinksBox(
 	const auto deleteAll = Ui::CreateChild<Ui::LinkButton>(
 		container.get(),
 		tr::lng_group_invite_context_delete_all(tr::now),
-		st::boxLinkButton);
+		st::defaultLinkButton);
 	rpl::combine(
 		header->topValue(),
 		container->widthValue()
diff --git a/Telegram/SourceFiles/data/data_histories.cpp b/Telegram/SourceFiles/data/data_histories.cpp
index 69ba4ddbc4..da2efa02c3 100644
--- a/Telegram/SourceFiles/data/data_histories.cpp
+++ b/Telegram/SourceFiles/data/data_histories.cpp
@@ -9,6 +9,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 
 #include "data/data_session.h"
 #include "data/data_channel.h"
+#include "data/data_chat.h"
 #include "data/data_folder.h"
 #include "data/data_scheduled_messages.h"
 #include "main/main_session.h"
@@ -599,11 +600,17 @@ void Histories::deleteAllMessages(
 			)).done([=](const MTPBool &result) {
 				finish();
 			}).fail(fail).send();
+		} else if (revoke && peer->isChat() && peer->asChat()->amCreator()) {
+			return session().api().request(MTPmessages_DeleteChat(
+				peer->asChat()->inputChat
+			)).done([=](const MTPBool &result) {
+				finish();
+			}).fail(fail).send();
 		} else {
 			using Flag = MTPmessages_DeleteHistory::Flag;
 			const auto flags = Flag(0)
 				| (justClear ? Flag::f_just_clear : Flag(0))
-				| ((peer->isUser() && revoke) ? Flag::f_revoke : Flag(0));
+				| (revoke ? Flag::f_revoke : Flag(0));
 			return session().api().request(MTPmessages_DeleteHistory(
 				MTP_flags(flags),
 				peer->input,
diff --git a/Telegram/SourceFiles/data/data_peer.cpp b/Telegram/SourceFiles/data/data_peer.cpp
index 75edd778ed..ac3f2074ce 100644
--- a/Telegram/SourceFiles/data/data_peer.cpp
+++ b/Telegram/SourceFiles/data/data_peer.cpp
@@ -825,6 +825,8 @@ bool PeerData::canRevokeFullHistory() const {
 			&& (!user->isBot() || user->isSupport())
 			&& session().serverConfig().revokePrivateInbox
 			&& (session().serverConfig().revokePrivateTimeLimit == 0x7FFFFFFF);
+	} else if (const auto chat = asChat()) {
+		return chat->amCreator();
 	}
 	return false;
 }