FocusIME/Redcraft.FocusIME/Source/Private/Main.cpp

#include "Defines.h"

#include <windows.h>
#include <iostream>
#include <fstream>
#include <thread>
#include <chrono>
#include <string>
#include <filesystem>
#include <ctime>
#include <iomanip>
#include <mutex>

#pragma warning(disable: 4996)

// ReSharper disable CppDeprecatedEntity
// ReSharper disable CppClangTidyCertErr33C

std::ofstream GLogFile;

void PrintLog(const std::string& Text)
{
	const auto Now  = std::chrono::system_clock::now();
	const auto Time = std::chrono::system_clock::to_time_t(Now);

	const long long Milliseconds = (std::chrono::duration_cast<std::chrono::milliseconds>(Now.time_since_epoch()) % 1000).count();

	static std::mutex Mutex; std::lock_guard Lock(Mutex);

	const std::tm* LocalTime = std::localtime(&Time); // NOLINT(concurrency-mt-unsafe)

	char Buffer[] = "[2025-06-21 20:05:04.305]: ";

	std::strftime(&Buffer[1], 20, "%Y-%m-%d %H:%M:%S", LocalTime);

	Buffer[20] = '.';

	constexpr char Digits[] = "0123456789";

	Buffer[21] = Digits[Milliseconds / 100 % 10];
	Buffer[22] = Digits[Milliseconds /  10 % 10];
	Buffer[23] = Digits[Milliseconds /   1 % 10];

	GLogFile << Buffer << Text << std::endl;
}

int WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
{
	using namespace std::chrono_literals;

	const HANDLE Mutex = CreateMutex(nullptr, TRUE, "FocusIME_SingleInstance_Mutex");

	if (Mutex == nullptr)
	{
		MessageBox(nullptr, "Failed to create mutex.", "FocusIME", MB_OK | MB_ICONERROR);

		return 1;
	}

	if (GetLastError() == ERROR_ALREADY_EXISTS)
	{
		MessageBox(nullptr, "FocusIME is already running.", "FocusIME", MB_OK | MB_ICONINFORMATION);

		CloseHandle(Mutex);

		return 0;
	}

	GLogFile.open("Log.txt", std::ios::out | std::ios::app);

	if (!GLogFile.is_open())
	{
		MessageBox(nullptr, "Failed to open log file.", "FocusIME", MB_OK | MB_ICONERROR);

		CloseHandle(Mutex);

		return 1;
	}

	PrintLog("FocusIME started successfully");

	MSG Message = { };

	while (true)
	{
		BOOL bResult = GetMessage(&Message, nullptr, 0, 0);

		if (bResult > 0)
		{
			TranslateMessage(&Message);
			DispatchMessage (&Message);
		}

		else break;
	}

	PrintLog("FocusIME is shutting down...");

	GLogFile.close();

	CloseHandle(Mutex);

	return 0;
}

// ReSharper restore CppDeprecatedEntity
// ReSharper restore CppClangTidyCertErr33C