/*
 * This file is part of VoidArchiveTool.
 *
 * Copyright (C) 2025 Yanczi
 *
 * Void Archive Toolis free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include "ExtractCargo.h"

ExtractCargo::ExtractCargo()
	:filesLen(0)
	, tablePosition(0)
	, filesHeadsOffset(0)
	, version(VERSION)
	, signature(SIGNATURE)
{
	// TODO Auto-generated constructor stub

}

ExtractCargo::~ExtractCargo()
{
	if (cargoFile.is_open())
	{
		cargoFile.close();
	}
}

//-----------------------------------------------------------------------------
//   Punkt wejścia
//-----------------------------------------------------------------------------
bool ExtractCargo::Extract(const std::string& cFile)
{
	cargoFileName = cFile;

	std::cout << "START EXTRACT " << cFile << std::endl;

	//Sprawdź czy plik istnieje
	if (!std::filesystem::exists(cargoFileName))
	{
		std::cerr << "Error: The given file is not exist!" << std::endl;
		return false;
	}

	//Sprawdź czy plik jets plikiem
	if (!std::filesystem::is_regular_file(cargoFileName))
	{
		std::cerr << "Error: The given file is a directory!" << std::endl;
		return false;
	}

	// Wczytaj klucz deszyfrujący
	std::filesystem::path kdir = cargoFileName.stem();
	if (std::filesystem::exists(kdir.string() + ".key"))
	{
		std::cout << "Decryption key detected" << std::endl;
		eman.loadKey(kdir.string());
	}

	//Otwieranie kontenera
	cargoFile.open(cargoFileName, std::ios::binary);

	if (!CheckCargoFile())
	{
		return false;
	}

	LoadFilesTable();
	ExtractingFilesFromCargo();

	return true;
}

//-----------------------------------------------------------------------------
//   Sprawdzenie poprawności archiwum
//-----------------------------------------------------------------------------
bool ExtractCargo::CheckCargoFile()
{
	std::vector<char> magic(signature.size());
	short cargoVer = 0;

	if (!cargoFile.is_open())
	{
		std::cerr << "Error: Failed to open container" << std::endl;
		return false;
	}

	cargoFile.read(magic.data(), magic.size());
	cargoFile.read(reinterpret_cast<char*>(&cargoVer), sizeof(cargoVer));
	cargoFile.read(reinterpret_cast<char*>(&filesLen), sizeof(filesLen));
	cargoFile.read(reinterpret_cast<char*>(&tablePosition), sizeof(tablePosition));

	if (std::string(magic.begin(), magic.end()) != signature)
	{
		std::cerr << "Error: Corrupted Cargo" << std::endl;
		return false;
	}

	if (cargoVer != version)
	{
		std::cerr << "Error: Wrong cargo version" << std::endl;
		return false;
	}

	filesHeadsOffset = signature.length() + sizeof(cargoVer) + sizeof(filesLen);

	return true;
}

//-----------------------------------------------------------------------------
//   Sprawdzanie sumy kontrolnej
//-----------------------------------------------------------------------------
bool ExtractCargo::HashValid(const std::vector<char>& data, const uint64_t& crc)
{
	uint64_t actualCrc = XXH64(data.data(), data.size(), VERSION);

	if (actualCrc != crc)
	{
		return false;
	}

	return true;
}

//-----------------------------------------------------------------------------
//   Magiczna funkcja do dekompresji i deszyfracji danych
//-----------------------------------------------------------------------------
void ExtractCargo::computingBytes(const std::vector<char>& input, std::vector<char>& output, const int16_t& flag)
{
	ChunkManager cm(eman);
	
	switch (flag)
	{
	case 1:
		output = cm.dechunked(input, false);
		break;
	
	case 2:
		output = eman.decrypt(input);
		break;
	
	case 3:
		output = cm.dechunked(input, false);
		break;
	
	default:
		output = input;
		break;
	}
}

//-----------------------------------------------------------------------------
//   Pobieranie nagłówków plików
//-----------------------------------------------------------------------------
void ExtractCargo::LoadFilesTable()
{
	cargoFile.seekg(tablePosition);
	for (uint32_t i = 0; i < filesLen; ++i)
	{
		FilesTable fhTmp;
		cargoFile.read(reinterpret_cast<char*>(&fhTmp.nameLen), sizeof(fhTmp.nameLen));

		std::vector<char> nameBuffor(fhTmp.nameLen);
		cargoFile.read(nameBuffor.data(), fhTmp.nameLen);
		fhTmp.nameFile = std::string(nameBuffor.begin(), nameBuffor.end());

		cargoFile.read(reinterpret_cast<char*>(&fhTmp.hashName), sizeof(fhTmp.hashName));
		cargoFile.read(reinterpret_cast<char*>(&fhTmp.offset), sizeof(fhTmp.offset));
		cargoFile.read(reinterpret_cast<char*>(&fhTmp.size), sizeof(fhTmp.size));
		cargoFile.read(reinterpret_cast<char*>(&fhTmp.crc), sizeof(fhTmp.crc));
		cargoFile.read(reinterpret_cast<char*>(&fhTmp.flag), sizeof(fhTmp.flag));

		filesHeads.push_back(fhTmp);
	}
}

//-----------------------------------------------------------------------------
//   Wypakowywanie plików
//-----------------------------------------------------------------------------
void ExtractCargo::ExtractingFilesFromCargo()
{
	for (const auto& fh : filesHeads)
	{
		std::filesystem::path dir = cargoFileName.stem() / fh.nameFile;
		CreateDirections(dir);
		std::ofstream file(dir, std::ios::binary);

		cargoFile.seekg(fh.offset);
		std::vector<char> buffor(fh.size);

		cargoFile.read(buffor.data(), fh.size);

		std::vector<char> rawBuffor;
		computingBytes(buffor, rawBuffor, fh.flag);

		if (!HashValid(rawBuffor, fh.crc))
		{
			std::cerr << fh.nameFile << "  Error: Corrupted data integration CRC" << std::endl;
		}

		file.write(reinterpret_cast<const char*>(rawBuffor.data()), rawBuffor.size());

		file.close();
	}

	std::cout << "Unpacking complete!" << std::endl;
}


//-----------------------------------------------------------------------------
//   Utwórz katalog
//-----------------------------------------------------------------------------
void ExtractCargo::CreateDirections(std::filesystem::path path)
{
	if (!std::filesystem::exists(path.parent_path()))
	{
		std::filesystem::create_directories(path.parent_path());
	}
}