Add local UDP discovery and invitation delivery for chat clients

tools/chatgui/src/mainwindow.cpp

@@ -209,6 +209,7 @@ MainWindow::~MainWindow() {
     s_mainWindow = nullptr;
     m_cpuLoadTimer->stop();
     gui_bridge_set_cpu_load_cb(nullptr);
+    gui_bridge_set_local_invite_cb(nullptr);
     DEBUG_DEBUG(DEBUG_CATEGORY_SYS, "desktop CPU indicator polling stopped");
     if (m_messageNotification) m_messageNotification->dismiss("shutdown");
     m_messageNotification.reset();
@@ -441,6 +442,22 @@ void MainWindow::setupSoundFromConfig() {
 
 void MainWindow::setupBridgeCallbacks() {
     s_mainWindow = this;
+    gui_bridge_set_local_invite_cb([](const uint8_t* data, int len) {
+        if (!s_mainWindow || len < 10 || 9 + data[8] >= len) {
+            DEBUG_WARN(DEBUG_CATEGORY_DISCOVERY, "invalid local invitation event bytes=%d", len); return;
+        }
+        QString name = QString::fromUtf8((const char*)data + 9, data[8]);
+        QString link = QString::fromUtf8((const char*)data + 9 + data[8], len - 9 - data[8]);
+        auto* window = s_mainWindow;
+        auto* prompt = new QMessageBox(QMessageBox::Question, QCoreApplication::translate("ChatGui", "Invitation"),
+            QCoreApplication::translate("ChatGui", "%1 sent an invitation over the local network. Connect?").arg(name),
+            QMessageBox::Yes | QMessageBox::No, window);
+        prompt->setTextFormat(Qt::PlainText); prompt->setAttribute(Qt::WA_DeleteOnClose);
+        QObject::connect(prompt, &QMessageBox::finished, window, [window, link](int result) {
+            if (result == QMessageBox::Yes) window->onMessageLinkActivated(link);
+        });
+        prompt->open();
+    });
     gui_bridge_set_cpu_load_cb([](int percent) {
         if (!s_mainWindow) return;
         s_mainWindow->m_cpuLoadPending = false;