ModUtils.h

#pragma once 

#include <Windows.h>
#include <string>
#include <cstdarg>
#include <fileapi.h>
#include <Psapi.h>
#include <iostream>
#include <vector>
#include <xinput.h>
#include <sstream>
#include <map>
#include <chrono>
#include <iomanip>

#include "ini.h"

namespace ModUtils
{
	static HWND muWindow = NULL;
	static std::string muGameName = "ELDEN RING";
	static std::string muExpectedWindowName = "ELDEN RING™";
	static std::ofstream muLogFile;
	static const std::string muAobMask = "?";

	class Timer
	{
	public:
		Timer(unsigned int intervalMs)
		{
			this->intervalMs = intervalMs;
		}

		bool Check()
		{
			if (firstCheck)
			{
				Reset();
				firstCheck = false;
			}

			auto now = std::chrono::system_clock::now();
			auto diff = std::chrono::duration_cast<std::chrono::milliseconds>(now - lastPassedCheckTime);
			if (diff.count() >= intervalMs)
			{
				lastPassedCheckTime = now;
				return true;
			}

			return false;
		}

		void Reset()
		{
			lastPassedCheckTime = std::chrono::system_clock::now();
		}

	private:
		unsigned int intervalMs = 0;
		bool firstCheck = true;
		std::chrono::system_clock::time_point lastPassedCheckTime;
	};

	static std::string _GetModuleName(bool mainProcessModule)
	{
		HMODULE module = NULL;

		if (!mainProcessModule)
		{
			static char dummyStaticVarToGetModuleHandle = 'x';
			GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT, &dummyStaticVarToGetModuleHandle, &module);
		}

		char lpFilename[MAX_PATH];
		GetModuleFileNameA(module, lpFilename, sizeof(lpFilename));
		std::string moduleName = strrchr(lpFilename, '\\');
		moduleName = moduleName.substr(1, moduleName.length());

		if (!mainProcessModule)
		{
			moduleName.erase(moduleName.find(".dll"), moduleName.length());
		}

		return moduleName;
	}

	static std::string GetCurrentProcessName()
	{
		return _GetModuleName(true);
	}

	static std::string GetCurrentModName()
	{
		static std::string currentModName = "NULL";
		if (currentModName == "NULL")
		{
			currentModName = _GetModuleName(false);
		}
		return currentModName;
	}

	static std::string GetModFolderPath()
	{
		return std::string("mods\\" + GetCurrentModName());
	}

	static void OpenModLogFile()
	{
		if (!muLogFile.is_open())
		{
			CreateDirectoryA(std::string("mods\\" + GetCurrentModName()).c_str(), NULL);
			muLogFile.open("mods\\" + GetCurrentModName() + "\\log.txt");
		}
	}

	template<typename... Types>
	static void Log(Types... args)
	{
		OpenModLogFile();

		std::stringstream stream;
		stream << GetCurrentModName() << " > ";
		(stream << ... << args) << std::endl;
		std::cout << stream.str();

		if (muLogFile.is_open())
		{
			muLogFile << stream.str();
			muLogFile.flush();
		}
	}

	static void CloseLog()
	{
		if (muLogFile.is_open())
		{
			muLogFile.close();
		}
	}

	static void ShowErrorPopup(std::string error)
	{
		GetCurrentModName();
		Log("Error popup: ", error);
		MessageBox(NULL, error.c_str(), GetCurrentModName().c_str(), MB_OK | MB_ICONERROR | MB_SYSTEMMODAL);
	}

	static DWORD_PTR GetProcessBaseAddress(DWORD processId)
	{
		DWORD_PTR baseAddress = 0;
		HANDLE processHandle = OpenProcess(PROCESS_ALL_ACCESS, FALSE, processId);
		HMODULE* moduleArray = nullptr;
		LPBYTE moduleArrayBytes = 0;
		DWORD bytesRequired = 0;

		if (processHandle)
		{
			if (EnumProcessModules(processHandle, NULL, 0, &bytesRequired))
			{
				if (bytesRequired)
				{
					moduleArrayBytes = (LPBYTE)LocalAlloc(LPTR, bytesRequired);
					if (moduleArrayBytes)
					{
						unsigned int moduleCount;
						moduleCount = bytesRequired / sizeof(HMODULE);
						moduleArray = (HMODULE*)moduleArrayBytes;
						if (EnumProcessModules(processHandle, moduleArray, bytesRequired, &bytesRequired))
						{
							baseAddress = (DWORD_PTR)moduleArray[0];
						}
						LocalFree(moduleArrayBytes);
					}
				}
			}
			CloseHandle(processHandle);
		}
		return baseAddress;
	}

	static void ToggleMemoryProtection(bool protectionEnabled, uintptr_t address, size_t size)
	{
		static std::map<uintptr_t, DWORD> protectionHistory;
		if (protectionEnabled && protectionHistory.find(address) != protectionHistory.end())
		{
			VirtualProtect((void*)address, size, protectionHistory[address], &protectionHistory[address]);
			protectionHistory.erase(address);
		}
		else if (!protectionEnabled && protectionHistory.find(address) == protectionHistory.end())
		{
			DWORD oldProtection = 0;
			VirtualProtect((void*)address, size, PAGE_EXECUTE_READWRITE, &oldProtection);
			protectionHistory[address] = oldProtection;
		}
	}

	static void MemCopy(uintptr_t destination, uintptr_t source, size_t numBytes)
	{
		ToggleMemoryProtection(false, destination, numBytes);
		ToggleMemoryProtection(false, source, numBytes);
		memcpy((void*)destination, (void*)source, numBytes);
		ToggleMemoryProtection(true, source, numBytes);
		ToggleMemoryProtection(true, destination, numBytes);
	}

	static void MemSet(uintptr_t address, unsigned char byte, size_t numBytes)
	{
		ToggleMemoryProtection(false, address, numBytes);
		memset((void*)address, byte, numBytes);
		ToggleMemoryProtection(true, address, numBytes);
	}

	static uintptr_t RelativeToAbsoluteAddress(uintptr_t relativeAddressLocation)
	{
		uintptr_t absoluteAddress = 0;
		intptr_t relativeAddress = 0;
		MemCopy((uintptr_t)&relativeAddress, relativeAddressLocation, 4);
		absoluteAddress = relativeAddressLocation + 4 + relativeAddress;
		return absoluteAddress;
	}

	static std::vector<std::string> TokenifyAobString(std::string aob)
	{
		std::istringstream iss(aob);
		std::vector<std::string> aobTokens {
			std::istream_iterator<std::string>{iss},
			std::istream_iterator<std::string>{}
		};
		return aobTokens;
	}

	static bool IsAobValid(std::vector<std::string> aobTokens)
	{
		for (auto byte : aobTokens)
		{
			if (byte == muAobMask)
			{
				continue;
			}

			if (byte.length() != 2)
			{
				return false;
			}

			std::string whitelist = "0123456789abcdef";
			if (byte.find_first_not_of(whitelist) != std::string::npos) 
			{
				return false;
			}
		}
		return true;
	}

	static bool VerifyAob(std::string aob)
	{
		std::vector<std::string> aobTokens = TokenifyAobString(aob);
		if (!IsAobValid(aobTokens))
		{
			ShowErrorPopup("AOB is invalid! (" + aob + ")");
			return false;
		};
		return true;
	}

	static bool VerifyAobs(std::vector<std::string> aobs)
	{
		for (auto aob : aobs)
		{
			if (!VerifyAob(aob))
			{
				return false;
			}
		}
		return true;
	}

	template<typename T>
	static std::string NumberToHexString(T number)
	{
		std::stringstream stream;
		stream
			<< std::setfill('0') 
			<< std::setw(sizeof(T) * 2)
			<< std::hex 
			<< number;
		return stream.str();
	}

	static std::string NumberToHexString(unsigned char number)
	{
		std::stringstream stream;
		stream
			<< std::setw(2)
			<< std::setfill('0')
			<< std::hex
			<< (unsigned int)number; // The << operator overload for unsigned chars screws us over unless this cast is done
		return stream.str();
	}
 
	static uintptr_t AobScan(std::string aob)
	{
		std::vector<std::string> aobTokens = TokenifyAobString(aob);

		DWORD processId = GetCurrentProcessId();
		uintptr_t regionStart = GetProcessBaseAddress(processId);
		Log("Process name: ", GetCurrentProcessName());
		Log("Process ID: ", processId);
		Log("Process base address: ", NumberToHexString(regionStart));
		Log("AOB: ", aob);

		if (!VerifyAob(aob))
		{
			return 0;
		};

		size_t numRegionsChecked = 0;
		size_t maxRegionsToCheck = 10000;
		uintptr_t currentAddress = 0;
		while (numRegionsChecked < maxRegionsToCheck)
		{
			MEMORY_BASIC_INFORMATION memoryInfo = { 0 };
			if (VirtualQuery((void*)regionStart, &memoryInfo, sizeof(MEMORY_BASIC_INFORMATION)) == 0)
			{
				DWORD error = GetLastError();
				if (error == ERROR_INVALID_PARAMETER)
				{
					Log("Reached end of scannable memory.");
				}
				else
				{
					Log("VirtualQuery failed, error code: ", error);
				}
				break;
			}
			regionStart = (uintptr_t)memoryInfo.BaseAddress;
			uintptr_t regionSize = (uintptr_t)memoryInfo.RegionSize;
			uintptr_t regionEnd = regionStart + regionSize;
			uintptr_t protection = (uintptr_t)memoryInfo.Protect;
			uintptr_t state = (uintptr_t)memoryInfo.State;

			bool isMemoryReadable = (
				protection == PAGE_EXECUTE_READWRITE
				|| protection == PAGE_READWRITE
				|| protection == PAGE_READONLY
				|| protection == PAGE_WRITECOPY
				|| protection == PAGE_EXECUTE_WRITECOPY)
				&& state == MEM_COMMIT;
			if (isMemoryReadable)
			{
				Log("Checking region: ", NumberToHexString(regionStart));
				currentAddress = regionStart;
				while (currentAddress < regionEnd - aobTokens.size())
				{
					for (size_t i = 0; i < aobTokens.size(); i++)
					{
						if (aobTokens[i] == muAobMask)
						{
							currentAddress++;
							continue;
						} 
						else if (*(unsigned char*)currentAddress != (unsigned char)std::stoul(aobTokens[i], nullptr, 16))
						{
							currentAddress++;
							break;
						}
						else if (i == aobTokens.size() - 1)
						{
							uintptr_t signature = currentAddress - aobTokens.size() + 1;
							Log("Found signature at ", NumberToHexString(signature));
							return signature;
						}
						currentAddress++;
					}
				}
			}
			else
			{
				Log("Skipped region: ", NumberToHexString(regionStart));
			}

			numRegionsChecked++;
			regionStart += memoryInfo.RegionSize;
		}

		Log("Stopped at: ", NumberToHexString(currentAddress), ", num regions checked: ", numRegionsChecked);
		ShowErrorPopup("Could not find signature!");
		return 0;
	}

	static std::vector<unsigned char> StringAobToRawAob(std::string aob)
	{
		std::vector<unsigned char> rawAob;
		std::vector<std::string> tokenifiedAob = TokenifyAobString(aob);
		for (size_t i = 0; i < tokenifiedAob.size(); i++)
		{
			if (tokenifiedAob[i] == muAobMask)
			{
				ShowErrorPopup("Cannot convert AOB with mask to raw AOB");
				return std::vector<unsigned char>();
			}

			unsigned char byte = (unsigned char)std::stoul(tokenifiedAob[i], nullptr, 16);
			rawAob.push_back(byte);
		}
		return rawAob;
	}

	static std::string RawAobToStringAob(std::vector<unsigned char> rawAob)
	{
		std::string aob;
		for (auto byte : rawAob)
		{
			std::string string = NumberToHexString(byte);
			aob += string + " ";
		}
		aob.pop_back();
		return aob;
	}

	static bool CheckIfAobsMatch(std::string aob1, std::string aob2)
	{
		std::vector<std::string> aob1Tokens = TokenifyAobString(aob1);
		std::vector<std::string> aob2Tokens = TokenifyAobString(aob2);

		size_t shortestAobLength = aob1Tokens.size() < aob2Tokens.size() ? aob1Tokens.size() : aob2Tokens.size();
		for (size_t i = 0; i < shortestAobLength; i++)
		{
			bool tokenIsMasked = aob1Tokens[i] == muAobMask || aob2Tokens[i] == muAobMask;
			if (tokenIsMasked)
			{
				continue;
			}

			if (aob1Tokens[i] != aob2Tokens[i])
			{
				ShowErrorPopup("Bytes do not match!");
				return false;
			}
		}
		return true;
	}

	static bool ReplaceExpectedBytesAtAddress(uintptr_t address, std::string expectedBytes, std::string newBytes)
	{
		if (!VerifyAobs({ expectedBytes, newBytes }))
		{
			return false;
		}

		std::vector<std::string> expectedBytesTokens = TokenifyAobString(expectedBytes);
		std::vector<unsigned char> existingBytesBuffer(expectedBytesTokens.size(), 0);
		MemCopy((uintptr_t)&existingBytesBuffer[0], address, existingBytesBuffer.size());
		std::string existingBytes = RawAobToStringAob(existingBytesBuffer);

		Log("Bytes at address: ", existingBytes);
		Log("Expected bytes: ", expectedBytes);
		Log("New bytes: ", newBytes);

		if (CheckIfAobsMatch(existingBytes, expectedBytes))
		{
			Log("Bytes match");
			std::vector<unsigned char> rawNewBytes = StringAobToRawAob(newBytes);
			MemCopy(address, (uintptr_t)&rawNewBytes[0], rawNewBytes.size());
			Log("Patch applied");
			return true;
		}

		return false;
	}

	static void GetWindowHandleByName(std::string windowName)
	{
		if (muWindow == NULL) 
		{
			for (size_t i = 0; i < 10000; i++)
			{
				HWND hwnd = FindWindowExA(NULL, NULL, NULL, windowName.c_str());
				DWORD processId = 0;
				GetWindowThreadProcessId(hwnd, &processId);
				if (processId == GetCurrentProcessId())
				{
					muWindow = hwnd;
					Log("FindWindowExA: found window handle");
					break;
				}
				Sleep(1);
			}
		}
	}

	static BOOL CALLBACK EnumWindowHandles(HWND hwnd, LPARAM lParam)
	{
		DWORD processId = NULL;
		GetWindowThreadProcessId(hwnd, &processId);
		if (processId == GetCurrentProcessId())
		{
			char buffer[100];
			GetWindowTextA(hwnd, buffer, 100);
			Log("Found window belonging to ER: ", buffer);
			if (std::string(buffer).find(muGameName) != std::string::npos)
			{
				Log(buffer, " handle selected");
				muWindow = hwnd;
				return false;
			}
		}
		return true;
	}

	static void GetWindowHandleByEnumeration()
	{
		if (muWindow == NULL)
		{
			Log("Enumerating windows...");
			for (size_t i = 0; i < 10000; i++)
			{
				EnumWindows(&EnumWindowHandles, NULL);
				if (muWindow != NULL)
				{
					break;
				}
				Sleep(1);
			}
		}
	}

	static bool GetWindowHandle()
	{
		Log("Finding application window...");

		GetWindowHandleByName(muExpectedWindowName);

		// From experience it can be tricky to find the game window consistently using only one technique,
		// (seems to differ from machine to machine for some reason) so we have this extra backup technique.
		GetWindowHandleByEnumeration();

		return (muWindow == NULL) ? false : true;
	}

	static void AttemptToGetWindowHandle()
	{
		static bool hasAttemptedToGetWindowHandle = false;

		if (!hasAttemptedToGetWindowHandle)
		{
			if (GetWindowHandle())
			{
				char buffer[100];
				GetWindowTextA(muWindow, buffer, 100);
				Log("Found application window: ", buffer);
			}
			else
			{
				Log("Failed to get window handle, inputs will be detected globally!");
			}
			hasAttemptedToGetWindowHandle = true;
		}
	}

	static bool AreKeysPressed(std::vector<unsigned short> keys, bool trueWhileHolding = false, bool checkController = false)
	{
		static std::vector<std::vector<unsigned short>> notReleasedKeys;

		AttemptToGetWindowHandle();

		bool ignoreOutOfFocusInput = muWindow != NULL && muWindow != GetForegroundWindow();
		if(ignoreOutOfFocusInput)
		{
			return false;
		}

		size_t numKeys = keys.size();
		size_t numKeysBeingPressed = 0;

		if (checkController)
		{
			for (DWORD controllerIndex = 0; controllerIndex < XUSER_MAX_COUNT; controllerIndex++)
			{
				XINPUT_STATE state = { 0 };
				DWORD result = XInputGetState(controllerIndex, &state);
				if (result == ERROR_SUCCESS)
				{
					for (auto key : keys)
					{
						if ((key & state.Gamepad.wButtons) == key)
						{
							numKeysBeingPressed++;
						}
					}
				}
			}
		}
		else
		{
			for (auto key : keys)
			{
				if (GetAsyncKeyState(key))
				{
					numKeysBeingPressed++;
				}
			}
		}

		auto iterator = std::find(notReleasedKeys.begin(), notReleasedKeys.end(), keys);
		bool keysBeingHeld = iterator != notReleasedKeys.end();
		if (numKeysBeingPressed == numKeys)
		{
			if (keysBeingHeld)
			{
				if (!trueWhileHolding)
				{
					return false;
				}
			}
			else
			{
				notReleasedKeys.push_back(keys);
			}
		}
		else
		{
			if (keysBeingHeld)
			{
				notReleasedKeys.erase(iterator);
			}
			return false;
		}

		return true;
	}

	static bool AreKeysPressed(unsigned short key, bool trueWhileHolding = false, bool checkController = false)
	{
		return AreKeysPressed({ key }, trueWhileHolding, checkController);
	}

	static void Hook(uintptr_t address, uintptr_t destination, size_t extraClearance = 0)
	{
		size_t clearance = 14 + extraClearance;
		MemSet(address, 0x90, clearance);
		*(uintptr_t*)address = 0x0000000025ff;
		MemCopy((address + 6), (uintptr_t)&destination, 8);
		Log("Created jump from ", NumberToHexString(address), " to ", NumberToHexString(destination),  " with a clearance of ", clearance);
	}
}