main.cpp

#include <fstream>
#include <filesystem>
#include <array>
#include <vector>
#include <string>
#include <optional>
#include <codecvt>
#include <iostream>
#include <set>

#include <windows.h>

struct FText
{
	std::wstring ns;
	std::wstring key;
	std::wstring s;
};

template <class T, size_t S>
bool test_signature(std::array<T, S> signature, std::vector<char> const& buffer, size_t index)
{
	if (buffer.size() < index + signature.size())
		return false;
	for (size_t i = 0; i < signature.size(); ++i)
		if (buffer[index + i] != signature[i])
			return false;
	return true;
}

bool good_ch(wchar_t ch)
{
	if (std::isprint(ch, std::locale{}))
		return true;
	if (ch == '\r')
		return true;
	if (ch == '\n')
		return true;
	return false;
}

bool very_good_key(std::wstring const& key)
{
	if (key.size() != 32)
		return false;
	for (const auto c : key)
		if (!(L'0' <= c && c <= L'9' || L'A' <= c && c <= L'F'))
			return false;
	return true;
}

bool good_s(std::wstring const& s)
{
	for (const auto c : s)
		if (std::isalpha(c, std::locale{}))
			return true;
	return false;
}

std::optional<std::pair<FText, size_t>> try_read_blueprint_text(std::vector<char> const& buffer, size_t index)
{
	constexpr std::array<char, 2> BLUEPRINT_TEXT_SIGNATURE = { 0x29, 0x01 };

	if (!test_signature(BLUEPRINT_TEXT_SIGNATURE, buffer, index))
		return std::nullopt;

	index += BLUEPRINT_TEXT_SIGNATURE.size();

	const auto read_to_null = [&] () -> std::optional<std::wstring> {
		if (buffer.size() <= index)
			return std::nullopt;

		if (buffer[index] == 0x1F) // ANSI
		{
			std::wstring s;
			for (++index; index < buffer.size(); ++index)
			{
				const auto ch = buffer[index];
				if (ch == 0)
				{
					++index;
					return s;
				}
				if (!good_ch(ch))
					return std::nullopt;
				s += ch;
			}
			return std::nullopt;
		}

		if (buffer[index] == 0x34) // UTF-16
		{
			std::wstring s;
			for (++index; index < buffer.size(); index += 2)
			{
				if (buffer.size() <= index + 1)
					return std::nullopt;
				const auto ch = *reinterpret_cast<const wchar_t*>(buffer.data() + index);
				if (ch == 0)
				{
					index += 2;
					return s;
				}
				if (!good_ch(ch))
					return std::nullopt;
				s += ch;
			}
			return std::nullopt;
		}

		return std::nullopt;
	};

	const auto s = read_to_null();
	if (!s.has_value())
		return std::nullopt;
	if (s->size() == 0)
		return std::nullopt;
	const auto key = read_to_null();
	if (!key.has_value())
		return std::nullopt;
	if (key->size() == 0)
		return std::nullopt;
	if (128 < key->size())   // static const int32 InlineStringSize = 128;
		return std::nullopt; // UE_CLOG(SaveNum > InlineStringSize, LogTextKey, VeryVerbose, TEXT("Key string '%s' was larger (%d) than the inline size (%d) and caused an allocation!"), OutStrBuffer.GetData(), SaveNum, InlineStringSize);
	if (!very_good_key(key.value()) && !good_s(s.value()))
		return std::nullopt;
	const auto ns = read_to_null();
	if (!ns.has_value())
		return std::nullopt;
	if (128 < ns->size())    // static const int32 InlineStringSize = 128;
		return std::nullopt; // UE_CLOG(SaveNum > InlineStringSize, LogTextKey, VeryVerbose, TEXT("Key string '%s' was larger (%d) than the inline size (%d) and caused an allocation!"), OutStrBuffer.GetData(), SaveNum, InlineStringSize);

	return std::pair{ FText{ ns.value(), key.value(), s.value() }, index };
}

std::optional<std::pair<FText, size_t>> try_read_ftext(std::vector<char> const& buffer, size_t index)
{
	if (buffer.size() < index + 5)
		return std::nullopt;

	const auto flag = *reinterpret_cast<const int*>(buffer.data() + index);
	index += 4;

	if (0b00011111 < flag) // highest flag right now: InitializedFromString = (1<<4)
		return std::nullopt;

	if (flag & 0b00000100) // ConvertedProperty = (1 << 2) never set in cooked text
		return std::nullopt;

	if (flag & 0b00010000) // InitializedFromString = (1 << 4) never set in cooked text
		return std::nullopt;

	const auto history = *reinterpret_cast<const char*>(buffer.data() + index);
	index += 1;

	if (history != 0) // support only ETextHistoryType::Base right now, should we support None = -1?
		return std::nullopt;

	const auto read_string = [&] () -> std::optional<std::wstring> {
		if (buffer.size() < index + 4)
			return std::nullopt;
		auto length = *reinterpret_cast<const int*>(buffer.data() + index);
		index += 4;
		if (length == 0)
			return L"";
		if (length < 0)
		{
			length = -length;
			if (buffer.size() < index + 2 * length)
				return std::nullopt;
			if (buffer[index + 2 * length - 2] != 0)
				return std::nullopt;
			if (buffer[index + 2 * length - 1] != 0)
				return std::nullopt;
			std::wstring s;
			for (size_t i = index; i < index + 2 * length - 2; i += 2)
			{
				const auto ch = *reinterpret_cast<const wchar_t*>(buffer.data() + i);
				if (ch == 0)
					return std::nullopt;
				if (!good_ch(ch))
					return std::nullopt;
				s += ch;
			}
			index += length + 2;
			return s;
		}
		else
		{
			if (buffer.size() < index + length)
				return std::nullopt;
			if (buffer[index + length - 1] != 0)
				return std::nullopt;
			std::wstring s;
			for (size_t i = index; i < index + length - 1; ++i)
			{
				const auto ch = buffer[i];
				if (ch == 0)
					return std::nullopt;
				if (!good_ch(ch))
					return std::nullopt;
				s += ch;
			}
			index += length;
			return s;
		}
	};

	const auto ns = read_string();
	if (!ns.has_value())
		return std::nullopt;
	if (128 < ns->size())    // static const int32 InlineStringSize = 128;
		return std::nullopt; // UE_CLOG(SaveNum > InlineStringSize, LogTextKey, VeryVerbose, TEXT("Key string '%s' was larger (%d) than the inline size (%d) and caused an allocation!"), OutStrBuffer.GetData(), SaveNum, InlineStringSize);
	const auto key = read_string();
	if (!key.has_value())
		return std::nullopt;
	if (key->size() == 0)
		return std::nullopt;
	if (128 < key->size())   // static const int32 InlineStringSize = 128;
		return std::nullopt; // UE_CLOG(SaveNum > InlineStringSize, LogTextKey, VeryVerbose, TEXT("Key string '%s' was larger (%d) than the inline size (%d) and caused an allocation!"), OutStrBuffer.GetData(), SaveNum, InlineStringSize);
	const auto s = read_string();
	if (!s.has_value())
		return std::nullopt;
	if (s->size() == 0)
		return std::nullopt;
	if (!very_good_key(key.value()) && !good_s(s.value()))
		return std::nullopt;

	const auto current_index = index;

	const auto impostor_check = read_string();
	if (impostor_check.has_value() && 0 < impostor_check->size())
		return std::nullopt;

	return std::pair{ FText{ ns.value(), key.value(), s.value() }, current_index };
}

void file_extract(std::filesystem::path root, std::filesystem::path file, std::vector<FText> & texts)
{
	if (!(file.extension() == ".uasset" || file.extension() == ".uexp" || file.extension() == ".umap"))
		return;

	std::wcout << std::filesystem::relative(file, root) << std::endl;

	auto fin = std::ifstream{ file, std::ios::binary | std::ios::ate };
	auto buffer = std::vector<char>(fin.tellg());
	fin.seekg(0, std::ios::beg);
	fin.read(buffer.data(), buffer.size());
	for (size_t i = 0; i < buffer.size(); ++i)
	{
		auto text = try_read_blueprint_text(buffer, i);
		if (text.has_value())
		{
			texts.push_back(text.value().first);
			i = text.value().second - 1;
			continue;
		}
		text = try_read_ftext(buffer, i);
		if (text.has_value())
		{
			texts.push_back(text.value().first);
			i = text.value().second - 1;
			continue;
		}
	}
}

void directory_extract(std::filesystem::path root, std::filesystem::path directory, std::vector<FText> & texts)
{
	for (auto const& entry : std::filesystem::directory_iterator(directory))
	{
		if (entry.is_directory())
			directory_extract(root, entry, texts);
		else
			file_extract(root, entry, texts);
	}
}

namespace crc32
{
	constexpr auto CRCTablesSB8 = std::array<unsigned int, 256>{
		0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
		0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
		0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
		0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
		0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
		0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
		0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
		0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
		0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
		0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
		0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
		0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
		0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
		0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
		0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
		0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
	};

	unsigned int StrCrc32_Unicode(std::wstring string)
	{
		std::vector<unsigned int> buf;
		for (size_t i = 0; i < string.size(); ++i)
		{
			buf.push_back(string[i] & 0xFF);
			buf.push_back((string[i] & 0xFF00) >> 8);
		}
		auto CRC = 0xFFFFFFFF;
		for (size_t i = 0; i < buf.size() / 2; ++i)
		{
			CRC = (CRC >> 8) ^ CRCTablesSB8[(CRC ^ buf[i * 2 + 0]) & 0xFF];
			CRC = (CRC >> 8) ^ CRCTablesSB8[(CRC ^ buf[i * 2 + 1]) & 0xFF];
			CRC = (CRC >> 8) ^ CRCTablesSB8[CRC & 0xFF];
			CRC = (CRC >> 8) ^ CRCTablesSB8[CRC & 0xFF];
		}
		return CRC ^ 0xFFFFFFFF;
	}

	unsigned int StrCrc32_ASCII(std::wstring string)
	{
		std::vector<unsigned int> buf;
		for (size_t i = 0; i < string.size(); ++i)
			buf.push_back(string[i]);
		auto CRC = 0xFFFFFFFF;
		for (size_t i = 0; i < buf.size(); ++i)
		{
			CRC = (CRC >> 8) ^ CRCTablesSB8[(CRC ^ buf[i]) & 0xFF];
			CRC = (CRC >> 8) ^ CRCTablesSB8[CRC & 0xFF];
			CRC = (CRC >> 8) ^ CRCTablesSB8[CRC & 0xFF];
			CRC = (CRC >> 8) ^ CRCTablesSB8[CRC & 0xFF];
		}
		return CRC ^ 0xFFFFFFFF;
	}

	unsigned int StrCrc32(std::wstring string)
	{
		bool bNeedUnicode = false;
		for (size_t i = 0; i < string.size(); ++i)
		{
			if (!(0x0000 <= string[i] && string[i] <= 0x00FF))
			{
				bNeedUnicode = true;
				break;
			}
		}
		if (bNeedUnicode)
			return StrCrc32_Unicode(string);
		else
			return StrCrc32_ASCII(string);
	}
}

int wmain(int argc, wchar_t ** argv)
{
	std::locale::global(std::locale{ std::locale::classic(), "en_US.UTF-8", std::locale::ctype });

	SetConsoleOutputCP(CP_UTF8);
	SetConsoleCP(CP_UTF8);

	if (argc < 3)
	{
		std::wcout
			<< L"UE4TextExtractor.exe <path to folder with extracted from pak files> <path to locres.txt file>" << std::endl << std::endl
			<< LR"(Example: UE4TextExtractor.exe "C:\MyGame\Content\Paks\unpacked" "C:\MyGame\Content\Paks\texts_to_locres.txt")" << std::endl
		;
		return 1;
	}

	std::vector<FText> texts;
	directory_extract(std::wstring(argv[1]), std::wstring(argv[1]), texts);

	std::set<std::wstring> namespaces;
	for (auto const& text : texts)
		namespaces.insert(text.ns);
	auto fout = std::wofstream{ std::wstring(argv[2]), std::ios::out };
	for (auto const& ns : namespaces)
	{
		fout << L"=>{" << ns << L"}" << std::endl << std::endl;
		std::set<std::wstring> unique_check;
		for (auto const& text : texts)
		{
			if (text.ns != ns)
				continue;
			if (unique_check.find(text.key) != unique_check.end())
				continue;
			unique_check.insert(text.key);
			fout << L"=>[" << text.key << L"][" << crc32::StrCrc32(text.s) << L"]" << std::endl << text.s << std::endl << std::endl;
		}
	}
	fout << L"=>{[END]}" << std::endl;
	return 0;
}