Handle conversion of historical CLEARCHAT messages to NOTICE messages in Chatterino instead of relying on the Recent Messages API to handle it for us (#1804)

This has historically been done in the Recent Messages API, but this functionality is being moved to Chatterino instead

* Remove `clearchatToNotice=true` query parameter to the Recent Messages API

src/providers/twitch/TwitchChannel.cpp

@@ -20,6 +20,7 @@
 #include "singletons/Settings.hpp"
 #include "singletons/Toasts.hpp"
 #include "singletons/WindowManager.hpp"
+#include "util/FormatTime.hpp"
 #include "util/PostToThread.hpp"
 #include "widgets/Window.hpp"
 
@@ -36,6 +37,47 @@ namespace {
     constexpr int TITLE_REFRESH_PERIOD = 10;
     constexpr char MAGIC_MESSAGE_SUFFIX[] = u8" \U000E0000";
 
+    // convertClearchatToNotice takes a Communi::IrcMessage that is a CLEARCHAT command and converts it to a readable NOTICE message
+    // This has historically been done in the Recent Messages API, but this functionality is being moved to Chatterino instead
+    auto convertClearchatToNotice(Communi::IrcMessage *message)
+    {
+        auto channelName = message->parameter(0);
+        QString noticeMessage{};
+        if (message->tags().contains("target-user-id"))
+        {
+            auto target = message->parameter(1);
+
+            if (message->tags().contains("ban-duration"))
+            {
+                // User was timed out
+                noticeMessage =
+                    QString("%1 has been timed out for %2.")
+                        .arg(target)
+                        .arg(formatTime(
+                            message->tag("ban-duration").toString()));
+            }
+            else
+            {
+                // User was permanently banned
+                noticeMessage =
+                    QString("%1 has been permanently banned.").arg(target);
+            }
+        }
+        else
+        {
+            // Chat was cleared
+            noticeMessage = "Chat has been cleared by a moderator.";
+        }
+
+        // rebuild the raw irc message so we can convert it back to an ircmessage again!
+        // this could probably be done in a smarter way
+        auto s = QString(":tmi.twitch.tv NOTICE %1 :%2")
+                     .arg(channelName)
+                     .arg(noticeMessage);
+
+        return Communi::IrcMessage::fromData(s.toUtf8(), nullptr);
+    }
+
     // parseRecentMessages takes a json object and returns a vector of
     // Communi IrcMessages
     auto parseRecentMessages(const QJsonObject &jsonRoot, ChannelPtr channel)
@@ -49,8 +91,15 @@ namespace {
         for (const auto jsonMessage : jsonMessages)
         {
             auto content = jsonMessage.toString().toUtf8();
-            messages.emplace_back(
-                Communi::IrcMessage::fromData(content, nullptr));
+
+            auto message = Communi::IrcMessage::fromData(content, nullptr);
+
+            if (message->command() == "CLEARCHAT")
+            {
+                message = convertClearchatToNotice(message);
+            }
+
+            messages.emplace_back(std::move(message));
         }
 
         return messages;