Migrate /announce command to Helix API. (#4003)

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

src/controllers/commands/CommandController.cpp

@@ -1568,6 +1568,70 @@ void CommandController::initialize(Settings &, Paths &paths)
 
         return "";
     });
+
+    this->registerCommand(
+        "/announce", [](const QStringList &words, auto channel) -> QString {
+            auto *twitchChannel = dynamic_cast<TwitchChannel *>(channel.get());
+            if (twitchChannel == nullptr)
+            {
+                channel->addMessage(makeSystemMessage(
+                    "This command can only be used in Twitch channels."));
+                return "";
+            }
+
+            if (words.size() < 2)
+            {
+                channel->addMessage(makeSystemMessage(
+                    "Usage: /announce <message> - Call attention to your "
+                    "message with a highlight."));
+                return "";
+            }
+
+            auto user = getApp()->accounts->twitch.getCurrent();
+            if (user->isAnon())
+            {
+                channel->addMessage(makeSystemMessage(
+                    "You must be logged in to use the /announce command"));
+                return "";
+            }
+
+            getHelix()->sendChatAnnouncement(
+                twitchChannel->roomId(), user->getUserId(),
+                words.mid(1).join(" "), HelixAnnouncementColor::Primary,
+                []() {
+                    // do nothing.
+                },
+                [channel](auto error, auto message) {
+                    using Error = HelixSendChatAnnouncementError;
+                    QString errorMessage =
+                        QString("Failed to send announcement - ");
+
+                    switch (error)
+                    {
+                        case Error::UserMissingScope: {
+                            // TODO(pajlada): Phrase MISSING_REQUIRED_SCOPE
+                            errorMessage +=
+                                "Missing required scope. Re-login with your "
+                                "account and try again.";
+                        }
+                        break;
+
+                        case Error::Forwarded: {
+                            errorMessage += message;
+                        }
+                        break;
+
+                        case Error::Unknown:
+                        default: {
+                            errorMessage += "An unknown error has occurred.";
+                        }
+                        break;
+                    }
+
+                    channel->addMessage(makeSystemMessage(errorMessage));
+                });
+            return "";
+        });
 }
 
 void CommandController::save()