// DLL.cpp : Defines the exported functions for the DLL.
//

#include "pch.h"
#include "framework.h"
#include "DLL.h"
#define DLLEXPORT extern "C" __declspec (dllexport)
// GlobalHook_Test.cpp : define the export functions of DLL application .


extern HMODULE g_hDllModule;  //save the Dll handle for calling by SetWindowsHookEx()

// to share the same memory with the host process
#pragma data_seg("mydata")
  //define a static variable g_hHook of the type HHook, initialize it by NULL
HHOOK g_hHook = NULL;
#pragma data_seg()
#pragma comment(linker, "/SECTION:mydata,RWS")

//The Hook Callback Function GetMsgProc
LRESULT CALLBACK GetMsgProc(
	int code,
	WPARAM wParam,
	LPARAM lParam)
{

	//add something here for debug
	// 1. show some messages
	int msgboxID = MessageBox(
		NULL,
		(LPCWSTR)L"Hello World",
		(LPCWSTR)L"123",
		NULL
	);
	//Pass the the next hook function if there is a hook function
	// to do ...
	return ::CallNextHookEx(g_hHook, code, wParam, lParam);
}

// Set the global hook
DLLEXPORT BOOL WINAPI  SetGlobalHook()
{
	//2. Use SetWindowsHookEx(p1,p2,p3,p4) to bind the
	//   keyboard message p1=WH_KEYBOARD with p2=(HOOKPROC)GetMsgProc, and p3 is the Dll handle, p4 is an int value
	g_hHook = SetWindowsHookEx(WH_KEYBOARD, &GetMsgProc, g_hDllModule, NULL);
	//to do ...
	//3. you can also add mouse messages here

	//to do ...
	if (NULL == g_hHook) // failure
	{
		return FALSE;
	}
	return TRUE; //success
}

// Unload the global hook
DLLEXPORT BOOL WINAPI UnsetGlobalHook()
{
	if (g_hHook)
	{
		//4. you cna also Unhook the Windows Hook "g_hHaook" here with UnHookWindowsHookEx(p1) by
		//   letting equal p1 to g_hHook
		//to do ...
		//4. you cna also Unhook the Windows Hook "g_hHook" here with UnHookWindowsHookEx(p1) by
		UnhookWindowsHookEx(g_hHook);
		 MessageBox(
			NULL,
			(LPCWSTR)L"Unhooked successfuly",
			(LPCWSTR)L"Unsetgloabl Hook",
			NULL
		);
	}
	return TRUE;
}