/*
  Copyright (C) 2001 Kimmo Pekkola

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License
  as published by the Free Software Foundation; either version 2
  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 General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

#define _CRTDBG_MAP_ALLOC
#include <crtdbg.h>
#include <Windows.h>
#include <ShellAPI.h>
#include <Shlwapi.h>

EXTERN_C IMAGE_DOS_HEADER __ImageBase;

typedef int (*RainmeterMainFunc)(LPWSTR cmdLine);

WCHAR* GetCommandLineArguments()
{
	WCHAR* args = GetCommandLine();

	// Skip past (quoted) application path in cmdLine.
	if (*args == L'"')
	{
		++args;  // Skip leading quote.
		while (*args && *args != L'"')
		{
			++args;
		}
		++args;  // Skip trailing quote.
	}
	else
	{
		while (*args && *args != L' ')
		{
			++args;
		}
	}

	// Skip leading whitespace (similar to CRT implementation).
	while (*args && *args <= L' ')
	{
		++args;
	}

	return args;
}

/*
** Attempts to load Rainmeter.dll. If it fails, retries after loading our own copies of the CRT
** DLLs in the Runtime directory.
*/
HINSTANCE LoadRainmeterLibrary()
{
	HINSTANCE rmDll = LoadLibrary(L"Rainmeter.dll");
	if (!rmDll)
	{
		WCHAR path[MAX_PATH];
		if (GetModuleFileName(nullptr, path, MAX_PATH) > 0)
		{
			PathRemoveFileSpec(path);
			PathAppend(path, L"Runtime");
			SetDllDirectory(path);
			PathAppend(path, L"msvcp120.dll");

			// Loading msvcpNNN.dll will load msvcrNNN.dll as well.
			HINSTANCE msvcrDll = LoadLibrary(path);
			SetDllDirectory(L"");

			if (msvcrDll)
			{
				rmDll = LoadLibrary(L"Rainmeter.dll");
				FreeLibrary(msvcrDll);
			}
		}
	}

	return rmDll;
}

/*
** Entry point. In Release builds, the entry point is Main() since the CRT is not used.
**
*/
int APIENTRY wWinMain(HINSTANCE, HINSTANCE, LPWSTR, int)
{
	_CrtSetDbgFlag(_CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF);
	//_CrtSetBreakAlloc(000);

	// Prevent system error message boxes.
	UINT oldMode = SetErrorMode(0);
	SetErrorMode(oldMode | SEM_FAILCRITICALERRORS);

	HINSTANCE instance = (HINSTANCE)&__ImageBase;
	WCHAR* args = GetCommandLineArguments();

	HRSRC iconResource = FindResource(instance, MAKEINTRESOURCE(1), RT_ICON);
	if (iconResource)
	{
		HINSTANCE rmDll = LoadRainmeterLibrary();
		if (rmDll)
		{
			auto rainmeterMain = (RainmeterMainFunc)GetProcAddress(rmDll, MAKEINTRESOURCEA(1));
			if (rainmeterMain)
			{
				return rainmeterMain(args);
			}
		}

		WCHAR message[128];
		wsprintf(
			message,
			L"Rainmeter.dll load error %ld.",
			GetLastError());
		MessageBox(nullptr, message, L"Rainmeter", MB_OK | MB_ICONERROR);
	}
	else
	{
		// Stub prodecure. If icon resources have been removed, try to launch the actual Rainmeter.exe.
		HKEY hKey;
		const REGSAM desiredSam = KEY_QUERY_VALUE | KEY_WOW64_32KEY;
		if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, L"Software\\Rainmeter", 0, desiredSam, &hKey) == ERROR_SUCCESS)
		{
			const DWORD size = MAX_PATH;
			WCHAR buffer[size];
			DWORD type = 0;
			if (RegQueryValueEx(hKey, nullptr , nullptr, &type, (LPBYTE)buffer, (LPDWORD)&size) == ERROR_SUCCESS &&
				type == REG_SZ)
			{
				SetCurrentDirectory(buffer);
				lstrcat(buffer, L"\\Rainmeter.exe");
				ShellExecute(nullptr, L"open", buffer, args, nullptr, SW_SHOWNORMAL);
			}
			RegCloseKey(hKey);
		}

		return 0;
	}

	return 1;
}

#ifndef _DEBUG
EXTERN_C int WINAPI Main()
{
	int result = wWinMain(nullptr, nullptr, nullptr, 0);
	ExitProcess(result);
	return 0;  // Never reached.
}
#endif