/* 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 "classfile.h"
#include "classparser.h"

#include <QFile>
#include <archive.h>
#include <archive_entry.h>
#include <QDebug>

namespace classparser
{

	QString GetMinecraftJarVersion(QString jarName)
	{
		QString version;

		// check if minecraft.jar exists
		QFile jar(jarName);
		if (!jar.exists())
			return version;

		// open jar with libarchive
		struct archive* a = archive_read_new();
		archive_read_support_format_zip(a);
		if (archive_read_open_filename(a, jarName.toUtf8().constData(),
									   10240) != ARCHIVE_OK) {
			archive_read_free(a);
			return version;
		}

		// find and read Minecraft.class
		QByteArray classData;
		struct archive_entry* entry;
		while (archive_read_next_header(a, &entry) == ARCHIVE_OK) {
			QString name = QString::fromUtf8(archive_entry_pathname(entry));
			if (name == "net/minecraft/client/Minecraft.class") {
				la_int64_t sz = archive_entry_size(entry);
				if (sz > 0) {
					classData.resize(sz);
					archive_read_data(a, classData.data(), sz);
				} else {
					char buf[8192];
					la_ssize_t r;
					while ((r = archive_read_data(a, buf, sizeof(buf))) > 0)
						classData.append(buf, r);
				}
				break;
			}
			archive_read_data_skip(a);
		}
		archive_read_free(a);

		if (classData.isEmpty())
			return version;

		// parse Minecraft.class
		try {
			char* temp = classData.data();
			qint64 size = classData.size();
			java::classfile MinecraftClass(temp, size);
			java::constant_pool constants = MinecraftClass.constants;
			for (java::constant_pool::container_type::const_iterator iter =
					 constants.begin();
				 iter != constants.end(); iter++) {
				const java::constant& constant = *iter;
				if (constant.type != java::constant_type_t::j_string_data)
					continue;
				const std::string& str = constant.str_data;
				qDebug() << QString::fromStdString(str);
				if (str.compare(0, 20, "Minecraft Minecraft ") == 0) {
					version = str.substr(20).data();
					break;
				}
			}
		} catch (const java::classfile_exception&) {
		}

		return version;
	}
} // namespace classparser