1 files changed, 114 insertions, 0 deletions
diff --git a/meshmc/launcher/minecraft/Rule.cpp b/meshmc/launcher/minecraft/Rule.cpp
new file mode 100644
index 0000000000..c77193790f
--- /dev/null
+++ b/meshmc/launcher/minecraft/Rule.cpp
@@ -0,0 +1,114 @@
+/* SPDX-FileCopyrightText: 2026 Project Tick
+ * SPDX-FileContributor: Project Tick
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ *   MeshMC - A Custom Launcher for Minecraft
+ *   Copyright (C) 2026 Project Tick
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ *  This file incorporates work covered by the following copyright and
+ *  permission notice:
+ *
+ * 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 <QJsonObject>
+#include <QJsonArray>
+
+#include "Rule.h"
+
+RuleAction RuleAction_fromString(QString name)
+{
+	if (name == "allow")
+		return Allow;
+	if (name == "disallow")
+		return Disallow;
+	return Defer;
+}
+
+QList<std::shared_ptr<Rule>> rulesFromJsonV4(const QJsonObject& objectWithRules)
+{
+	QList<std::shared_ptr<Rule>> rules;
+	auto rulesVal = objectWithRules.value("rules");
+	if (!rulesVal.isArray())
+		return rules;
+
+	QJsonArray ruleList = rulesVal.toArray();
+	for (auto ruleVal : ruleList) {
+		std::shared_ptr<Rule> rule;
+		if (!ruleVal.isObject())
+			continue;
+		auto ruleObj = ruleVal.toObject();
+		auto actionVal = ruleObj.value("action");
+		if (!actionVal.isString())
+			continue;
+		auto action = RuleAction_fromString(actionVal.toString());
+		if (action == Defer)
+			continue;
+
+		auto osVal = ruleObj.value("os");
+		if (!osVal.isObject()) {
+			// add a new implicit action rule
+			rules.append(ImplicitRule::create(action));
+			continue;
+		}
+
+		auto osObj = osVal.toObject();
+		auto osNameVal = osObj.value("name");
+		if (!osNameVal.isString())
+			continue;
+		OpSys requiredOs = OpSys_fromString(osNameVal.toString());
+		QString versionRegex = osObj.value("version").toString();
+		// add a new OS rule
+		rules.append(OsRule::create(action, requiredOs, versionRegex));
+	}
+	return rules;
+}
+
+QJsonObject ImplicitRule::toJson()
+{
+	QJsonObject ruleObj;
+	ruleObj.insert("action",
+				   m_result == Allow ? QString("allow") : QString("disallow"));
+	return ruleObj;
+}
+
+QJsonObject OsRule::toJson()
+{
+	QJsonObject ruleObj;
+	ruleObj.insert("action",
+				   m_result == Allow ? QString("allow") : QString("disallow"));
+	QJsonObject osObj;
+	{
+		osObj.insert("name", OpSys_toString(m_system));
+		if (!m_version_regexp.isEmpty()) {
+			osObj.insert("version", m_version_regexp);
+		}
+	}
+	ruleObj.insert("os", osObj);
+	return ruleObj;
+}