refactor header and code into 2 files

launcher/ui/pages/instance/McResolver.cpp

@@ -0,0 +1,72 @@
+#include <QObject>
+#include <QDnsLookup>
+#include <QtNetwork/qtcpsocket.h>
+#include <QHostInfo>
+
+#include "McResolver.hpp"
+
+MCResolver::MCResolver(QObject *parent, QString domain, int port): QObject(parent), constrDomain(domain), constrPort(port) {}
+
+void MCResolver::ping() {
+    pingWithDomainSRV(constrDomain, constrPort);
+}
+
+void MCResolver::pingWithDomainSRV(QString domain, int port) {
+    QDnsLookup *lookup = new QDnsLookup(this);
+    lookup->setName(QString("_minecraft._tcp.%1").arg(domain));
+    lookup->setType(QDnsLookup::SRV);
+
+    connect(lookup, &QDnsLookup::finished, this, [&, domain, port]() {
+        QDnsLookup *lookup = qobject_cast<QDnsLookup *>(sender());
+
+        lookup->deleteLater();
+
+        if (lookup->error() != QDnsLookup::NoError) {
+            qDebug() << QString("Warning: SRV record lookup failed (%1), trying A record lookup").arg(lookup->errorString());
+            pingWithDomainA(domain, port);
+            return;
+        }
+
+        auto records = lookup->serviceRecords();
+        if (records.isEmpty()) {
+            qDebug() << "Warning: no SRV entries found for domain, trying A record lookup";
+            pingWithDomainA(domain, port);
+            return;
+        }
+
+
+        const auto& firstRecord = records.at(0);
+        QString domain = firstRecord.target();
+        int port = firstRecord.port();
+        pingWithDomainA(domain, port);
+    });
+
+    lookup->lookup();
+}
+
+void MCResolver::pingWithDomainA(QString domain, int port) {
+    QHostInfo::lookupHost(domain, this, [&, port](const QHostInfo &hostInfo){
+        if (hostInfo.error() != QHostInfo::NoError) {
+            emitFail("A record lookup failed");
+            return;
+        } else {
+            auto records = hostInfo.addresses();
+            if (records.isEmpty()) {
+                emitFail("No A entries found for domain");
+                return;
+            }
+            
+            const auto& firstRecord = records.at(0);
+            emitSucceed(firstRecord.toString(), port);
+        }
+    });        
+}
+
+void MCResolver::emitFail(std::string error) {
+    qDebug() << "Ping error:" << QString::fromStdString(error);
+    emit fail();
+}
+
+void MCResolver::emitSucceed(QString ip, int port) {
+    emit succeed(ip, port);
+}