GH-3392 dirty initial MSA support that shares logic with Mojang flows

Both act as the first step of AuthContext.

launcher/minecraft/auth/AccountTask.cpp

@@ -0,0 +1,69 @@
+/* Copyright 2013-2021 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "AccountTask.h"
+#include "MinecraftAccount.h"
+
+#include <QObject>
+#include <QString>
+#include <QJsonObject>
+#include <QJsonDocument>
+#include <QNetworkReply>
+#include <QByteArray>
+
+#include <Env.h>
+
+#include <BuildConfig.h>
+
+#include <QDebug>
+
+AccountTask::AccountTask(AccountData *data, QObject *parent)
+    : Task(parent), m_data(data)
+{
+    changeState(STATE_CREATED);
+}
+
+QString AccountTask::getStateMessage() const
+{
+    switch (m_accountState)
+    {
+    case STATE_CREATED:
+        return "Waiting...";
+    case STATE_WORKING:
+        return tr("Sending request to auth servers...");
+    case STATE_SUCCEEDED:
+        return tr("Authentication task succeeded.");
+    case STATE_FAILED_SOFT:
+        return tr("Failed to contact the authentication server.");
+    case STATE_FAILED_HARD:
+        return tr("Failed to authenticate.");
+    default:
+        return tr("...");
+    }
+}
+
+void AccountTask::changeState(AccountTask::State newState, QString reason)
+{
+    m_accountState = newState;
+    setStatus(getStateMessage());
+    if (newState == STATE_SUCCEEDED)
+    {
+        emitSucceeded();
+    }
+    else if (newState == STATE_FAILED_HARD || newState == STATE_FAILED_SOFT)
+    {
+        emitFailed(reason);
+    }
+}