/*
 * 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)
	, xxhState(XXH64_createState())
	, signature(SIGNATURE)
{
	// TODO Auto-generated constructor stub
	XXH64_reset(xxhState, 0);
}

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());
	int8_t cargoVer = 0;

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

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

	// Pobierz pozycję tablicy plików i jej rozmiar
	cargoFile.read(reinterpret_cast<char*>(&tablePosition), sizeof(tablePosition));
	cargoFile.read(reinterpret_cast<char*>(&filesLen), sizeof(filesLen));

	return true;
}

//-----------------------------------------------------------------------------
//   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.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::cout << dir.string() << std::endl;

		std::ofstream file(dir, std::ios::binary);
		cargoFile.seekg(fh.offset);

		XXH64_reset(xxhState, 0);

		// Strumień wyciągający
		if (fh.flag == flag::raw)
		{
			for (uint64_t sc = 0; sc < fh.size; sc += ds::chunk_stream)
			{
				const uint32_t streamChunk = std::min(ds::chunk_stream, static_cast<uint32_t>(fh.size - sc));

				std::vector<char> buffer(streamChunk);
				cargoFile.read(buffer.data(), streamChunk);
				XXH64_update(xxhState, buffer.data(), buffer.size());
				file.write(reinterpret_cast<const char*>(buffer.data()), streamChunk);
			}
		}
		else
		{
			uint32_t chunkLen;
			uint32_t chunkBeforeSize;
			uint32_t chunkLastSize;

			cargoFile.read(reinterpret_cast<char*>(&chunkLen), sizeof(chunkLen));
			cargoFile.read(reinterpret_cast<char*>(&chunkBeforeSize), sizeof(chunkBeforeSize));
			cargoFile.read(reinterpret_cast<char*>(&chunkLastSize), sizeof(chunkLastSize));

			std::vector<char> chunksString;

			// Dekompresja bloków
			for (size_t i = 0; i < chunkLen; ++i)
			{
				// Pobierz rozmiar chunków przed i po skompresowaniem
				uint32_t chunkSize = i < chunkLen - 1 ? chunkBeforeSize : chunkLastSize;

				uint32_t chunkZipSize;
				cargoFile.read(reinterpret_cast<char*>(&chunkZipSize), sizeof(chunkZipSize));

				// Pobierz blok chunka
				std::vector<char> buffer(chunkZipSize);
				cargoFile.read(buffer.data(), chunkZipSize);

				std::vector<char> rawBuffer(chunkSize);
				if ((fh.flag & flag::zip) == flag::zip)
				{
					rawBuffer = (fh.flag & flag::enc) == flag::enc ?
						cman.decompress(eman.decrypt(buffer), chunkSize) :
						cman.decompress(buffer, chunkSize);
				}
				else
				{
					rawBuffer = eman.decrypt(buffer);
				}

				XXH64_update(xxhState, rawBuffer.data(), rawBuffer.size());
				file.write(reinterpret_cast<const char*>(rawBuffer.data()), chunkSize);
			}
		}

		file.close();

		if (XXH64_digest(xxhState) != fh.crc)
		{
			std::cerr << dir.string() << "  Error: Corrupted data integration CRC" << std::endl;

		}
	}

	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());
	}
}