Add 'meshmc/' from commit 'fad6a1066616b69d7f5fef01178efdf014c59537'

git-subtree-dir: meshmc
git-subtree-mainline: 934382c8a1ce738589dee9ee0f14e1cec812770e
git-subtree-split: fad6a1066616b69d7f5fef01178efdf014c59537

1 files changed, 478 insertions, 0 deletions

diff --git a/meshmc/launcher/minecraft/World.cpp b/meshmc/launcher/minecraft/World.cpp
new file mode 100644
index 0000000000..4ae59afaf5
--- /dev/null
+++ b/meshmc/launcher/minecraft/World.cpp
@@ -0,0 +1,478 @@
+/* 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 2015-2021 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 <QDir>
+#include <QString>
+#include <QDebug>
+#include <QSaveFile>
+#include "World.h"
+
+#include "GZip.h"
+#include <MMCZip.h>
+#include <FileSystem.h>
+#include <sstream>
+#include <io/stream_reader.h>
+#include <tag_string.h>
+#include <tag_primitive.h>
+
+#include <QCoreApplication>
+
+#include <nonstd/optional>
+
+using nonstd::nullopt;
+using nonstd::optional;
+
+GameType::GameType(nonstd::optional<int> original) : original(original)
+{
+	if (!original) {
+		return;
+	}
+	switch (*original) {
+		case 0:
+			type = GameType::Survival;
+			break;
+		case 1:
+			type = GameType::Creative;
+			break;
+		case 2:
+			type = GameType::Adventure;
+			break;
+		case 3:
+			type = GameType::Spectator;
+			break;
+		default:
+			break;
+	}
+}
+
+QString GameType::toTranslatedString() const
+{
+	switch (type) {
+		case GameType::Survival:
+			return QCoreApplication::translate("GameType", "Survival");
+		case GameType::Creative:
+			return QCoreApplication::translate("GameType", "Creative");
+		case GameType::Adventure:
+			return QCoreApplication::translate("GameType", "Adventure");
+		case GameType::Spectator:
+			return QCoreApplication::translate("GameType", "Spectator");
+		default:
+			break;
+	}
+	if (original) {
+		return QCoreApplication::translate("GameType", "Unknown (%1)")
+			.arg(*original);
+	}
+	return QCoreApplication::translate("GameType", "Undefined");
+}
+
+QString GameType::toLogString() const
+{
+	switch (type) {
+		case GameType::Survival:
+			return "Survival";
+		case GameType::Creative:
+			return "Creative";
+		case GameType::Adventure:
+			return "Adventure";
+		case GameType::Spectator:
+			return "Spectator";
+		default:
+			break;
+	}
+	if (original) {
+		return QString("Unknown (%1)").arg(*original);
+	}
+	return "Undefined";
+}
+
+std::unique_ptr<nbt::tag_compound> parseLevelDat(QByteArray data)
+{
+	QByteArray output;
+	if (!GZip::unzip(data, output)) {
+		return nullptr;
+	}
+	std::istringstream foo(std::string(output.constData(), output.size()));
+	try {
+		auto pair = nbt::io::read_compound(foo);
+
+		if (pair.first != "")
+			return nullptr;
+
+		if (pair.second == nullptr)
+			return nullptr;
+
+		return std::move(pair.second);
+	} catch (const nbt::io::input_error& e) {
+		qWarning() << "Unable to parse level.dat:" << e.what();
+		return nullptr;
+	}
+}
+
+QByteArray serializeLevelDat(nbt::tag_compound* levelInfo)
+{
+	std::ostringstream s;
+	nbt::io::write_tag("", *levelInfo, s);
+	QByteArray val(s.str().data(), (int)s.str().size());
+	return val;
+}
+
+QString getLevelDatFromFS(const QFileInfo& file)
+{
+	QDir worldDir(file.filePath());
+	if (!file.isDir() || !worldDir.exists("level.dat")) {
+		return QString();
+	}
+	return worldDir.absoluteFilePath("level.dat");
+}
+
+QByteArray getLevelDatDataFromFS(const QFileInfo& file)
+{
+	auto fullFilePath = getLevelDatFromFS(file);
+	if (fullFilePath.isNull()) {
+		return QByteArray();
+	}
+	QFile f(fullFilePath);
+	if (!f.open(QIODevice::ReadOnly)) {
+		return QByteArray();
+	}
+	return f.readAll();
+}
+
+bool putLevelDatDataToFS(const QFileInfo& file, QByteArray& data)
+{
+	auto fullFilePath = getLevelDatFromFS(file);
+	if (fullFilePath.isNull()) {
+		return false;
+	}
+	QSaveFile f(fullFilePath);
+	if (!f.open(QIODevice::WriteOnly)) {
+		return false;
+	}
+	QByteArray compressed;
+	if (!GZip::zip(data, compressed)) {
+		return false;
+	}
+	if (f.write(compressed) != compressed.size()) {
+		f.cancelWriting();
+		return false;
+	}
+	return f.commit();
+}
+
+World::World(const QFileInfo& file)
+{
+	repath(file);
+}
+
+void World::repath(const QFileInfo& file)
+{
+	m_containerFile = file;
+	m_folderName = file.fileName();
+	if (file.isFile() && file.suffix() == "zip") {
+		m_iconFile = QString();
+		readFromZip(file);
+	} else if (file.isDir()) {
+		QFileInfo assumedIconPath(file.absoluteFilePath() + "/icon.png");
+		if (assumedIconPath.exists()) {
+			m_iconFile = assumedIconPath.absoluteFilePath();
+		}
+		readFromFS(file);
+	}
+}
+
+bool World::resetIcon()
+{
+	if (m_iconFile.isNull()) {
+		return false;
+	}
+	if (QFile(m_iconFile).remove()) {
+		m_iconFile = QString();
+		return true;
+	}
+	return false;
+}
+
+void World::readFromFS(const QFileInfo& file)
+{
+	auto bytes = getLevelDatDataFromFS(file);
+	if (bytes.isEmpty()) {
+		is_valid = false;
+		return;
+	}
+	loadFromLevelDat(bytes);
+	levelDatTime = file.lastModified();
+}
+
+void World::readFromZip(const QFileInfo& file)
+{
+	QString zipPath = file.absoluteFilePath();
+	auto location = MMCZip::findFolderOfFileInZip(zipPath, "level.dat");
+	is_valid = !location.isEmpty();
+	if (!is_valid) {
+		return;
+	}
+	m_containerOffsetPath = location;
+	QByteArray levelDatData =
+		MMCZip::readFileFromZip(zipPath, location + "level.dat");
+	is_valid = !levelDatData.isEmpty();
+	if (!is_valid) {
+		return;
+	}
+	levelDatTime = MMCZip::getEntryModTime(zipPath, location + "level.dat");
+	loadFromLevelDat(levelDatData);
+}
+
+bool World::install(const QString& to, const QString& name)
+{
+	auto finalPath =
+		FS::PathCombine(to, FS::DirNameFromString(m_actualName, to));
+	if (!FS::ensureFolderPathExists(finalPath)) {
+		return false;
+	}
+	bool ok = false;
+	if (m_containerFile.isFile()) {
+		auto result = MMCZip::extractSubDir(m_containerFile.absoluteFilePath(),
+											m_containerOffsetPath, finalPath);
+		ok = result.has_value();
+	} else if (m_containerFile.isDir()) {
+		QString from = m_containerFile.filePath();
+		ok = FS::copy(from, finalPath)();
+	}
+
+	if (ok && !name.isEmpty() && m_actualName != name) {
+		World newWorld{QFileInfo(finalPath)};
+		if (newWorld.isValid()) {
+			newWorld.rename(name);
+		}
+	}
+	return ok;
+}
+
+bool World::rename(const QString& newName)
+{
+	if (m_containerFile.isFile()) {
+		return false;
+	}
+
+	auto data = getLevelDatDataFromFS(m_containerFile);
+	if (data.isEmpty()) {
+		return false;
+	}
+
+	auto worldData = parseLevelDat(data);
+	if (!worldData) {
+		return false;
+	}
+	auto& val = worldData->at("Data");
+	if (val.get_type() != nbt::tag_type::Compound) {
+		return false;
+	}
+	auto& dataCompound = val.as<nbt::tag_compound>();
+	dataCompound.put("LevelName",
+					 nbt::value_initializer(newName.toUtf8().data()));
+	data = serializeLevelDat(worldData.get());
+
+	putLevelDatDataToFS(m_containerFile, data);
+
+	m_actualName = newName;
+
+	QDir parentDir(m_containerFile.absoluteFilePath());
+	parentDir.cdUp();
+	QFile container(m_containerFile.absoluteFilePath());
+	auto dirName =
+		FS::DirNameFromString(m_actualName, parentDir.absolutePath());
+	container.rename(parentDir.absoluteFilePath(dirName));
+
+	return true;
+}
+
+namespace
+{
+
+	optional<QString> read_string(nbt::value& parent, const char* name)
+	{
+		try {
+			auto& namedValue = parent.at(name);
+			if (namedValue.get_type() != nbt::tag_type::String) {
+				return nullopt;
+			}
+			auto& tag_str = namedValue.as<nbt::tag_string>();
+			return QString::fromStdString(tag_str.get());
+		} catch (const std::out_of_range& e) {
+			// fallback for old world formats
+			qWarning() << "String NBT tag" << name << "could not be found.";
+			return nullopt;
+		} catch (const std::bad_cast& e) {
+			// type mismatch
+			qWarning() << "NBT tag" << name
+					   << "could not be converted to string.";
+			return nullopt;
+		}
+	}
+
+	optional<int64_t> read_long(nbt::value& parent, const char* name)
+	{
+		try {
+			auto& namedValue = parent.at(name);
+			if (namedValue.get_type() != nbt::tag_type::Long) {
+				return nullopt;
+			}
+			auto& tag_str = namedValue.as<nbt::tag_long>();
+			return tag_str.get();
+		} catch (const std::out_of_range& e) {
+			// fallback for old world formats
+			qWarning() << "Long NBT tag" << name << "could not be found.";
+			return nullopt;
+		} catch (const std::bad_cast& e) {
+			// type mismatch
+			qWarning() << "NBT tag" << name
+					   << "could not be converted to long.";
+			return nullopt;
+		}
+	}
+
+	optional<int> read_int(nbt::value& parent, const char* name)
+	{
+		try {
+			auto& namedValue = parent.at(name);
+			if (namedValue.get_type() != nbt::tag_type::Int) {
+				return nullopt;
+			}
+			auto& tag_str = namedValue.as<nbt::tag_int>();
+			return tag_str.get();
+		} catch (const std::out_of_range& e) {
+			// fallback for old world formats
+			qWarning() << "Int NBT tag" << name << "could not be found.";
+			return nullopt;
+		} catch (const std::bad_cast& e) {
+			// type mismatch
+			qWarning() << "NBT tag" << name << "could not be converted to int.";
+			return nullopt;
+		}
+	}
+
+	GameType read_gametype(nbt::value& parent, const char* name)
+	{
+		return GameType(read_int(parent, name));
+	}
+
+} // namespace
+
+void World::loadFromLevelDat(QByteArray data)
+{
+	auto levelData = parseLevelDat(data);
+	if (!levelData) {
+		is_valid = false;
+		return;
+	}
+
+	nbt::value* valPtr = nullptr;
+	try {
+		valPtr = &levelData->at("Data");
+	} catch (const std::out_of_range& e) {
+		qWarning() << "Unable to read NBT tags from " << m_folderName << ":"
+				   << e.what();
+		is_valid = false;
+		return;
+	}
+	nbt::value& val = *valPtr;
+
+	is_valid = val.get_type() == nbt::tag_type::Compound;
+	if (!is_valid)
+		return;
+
+	auto name = read_string(val, "LevelName");
+	m_actualName = name ? *name : m_folderName;
+
+	auto timestamp = read_long(val, "LastPlayed");
+	m_lastPlayed =
+		timestamp ? QDateTime::fromMSecsSinceEpoch(*timestamp) : levelDatTime;
+
+	m_gameType = read_gametype(val, "GameType");
+
+	optional<int64_t> randomSeed;
+	try {
+		auto& WorldGen_val = val.at("WorldGenSettings");
+		randomSeed = read_long(WorldGen_val, "seed");
+	} catch (const std::out_of_range&) {
+	}
+	if (!randomSeed) {
+		randomSeed = read_long(val, "RandomSeed");
+	}
+	m_randomSeed = randomSeed ? *randomSeed : 0;
+
+	qDebug() << "World Name:" << m_actualName;
+	qDebug() << "Last Played:" << m_lastPlayed.toString();
+	if (randomSeed) {
+		qDebug() << "Seed:" << *randomSeed;
+	}
+	qDebug() << "GameType:" << m_gameType.toLogString();
+}
+
+bool World::replace(World& with)
+{
+	if (!destroy())
+		return false;
+	bool success =
+		FS::copy(with.m_containerFile.filePath(), m_containerFile.path())();
+	if (success) {
+		m_folderName = with.m_folderName;
+		m_containerFile.refresh();
+	}
+	return success;
+}
+
+bool World::destroy()
+{
+	if (!is_valid)
+		return false;
+	if (m_containerFile.isDir()) {
+		QDir d(m_containerFile.filePath());
+		return d.removeRecursively();
+	} else if (m_containerFile.isFile()) {
+		QFile file(m_containerFile.absoluteFilePath());
+		return file.remove();
+	}
+	return true;
+}
+
+bool World::operator==(const World& other) const
+{
+	return is_valid == other.is_valid && folderName() == other.folderName();
+}