#define _WIN32_WINNT 0x0501
#include <windows.h>

#include <stdio.h>

static HINSTANCE g_hInstance;

LRESULT CALLBACK hook_proc( int code, WPARAM wparam, LPARAM lparam )
{
    MSLLHOOKSTRUCT *hook = (MSLLHOOKSTRUCT *)lparam;
    POINT pt;
    GetCursorPos(&pt);

    if (code == HC_ACTION)
    {
        printf("code=%d w=%p [(%ld %ld) %lx %lx %p] cur(%ld %ld) dl(%ld %ld)\n", code, wparam,
                hook->pt.x, hook->pt.y, hook->mouseData, hook->flags, hook->dwExtraInfo,
                pt.x, pt.y, hook->pt.x - pt.x, hook->pt.y - pt.y);
    }
    return CallNextHookEx( 0, code, wparam, lparam );
}

#define SEND(x,y) \
    i.mi.time = GetCurrentTime(); \
    i.mi.dx = x; i.mi.dy = y; \
    SendInput(1, &i, sizeof(INPUT));

inline void send_abs(int x, int y, LPINPUT i, LPPOINT pt)
{
    int accel[3], xMult = 1, yMult = 1;
    int width  = GetSystemMetrics(SM_CXSCREEN);
    int height = GetSystemMetrics(SM_CYSCREEN);
    
    SystemParametersInfoW(SPI_GETMOUSE, 0, accel, 0);

    if (abs(x) > accel[0] && accel[2] != 0) {
        if ((abs(x) > accel[1]) && (accel[2] == 2)) xMult = 4; else xMult = 2;
    }
    if (abs(y) > accel[0] && accel[2] != 0) {
        if ((abs(y) > accel[1]) && (accel[2] == 2)) yMult = 4; else yMult = 2;
    }
    i->mi.dx = ((pt->x + (long)(x) * xMult) << 16) / width;
    i->mi.dy = ((pt->y + (long)(y) * yMult) << 16) / height;

    i->mi.time = GetCurrentTime();
    SendInput(1, i, sizeof(INPUT));
}


void send_input(void)
{
    INPUT i;
    POINT pt, ptorg;

    GetCursorPos(&ptorg);
    pt = ptorg;
    printf("Cur pos: %ld %ld\n", ptorg.x, ptorg.y);

    i.type = INPUT_MOUSE;
    i.mi.dwFlags = MOUSEEVENTF_MOVE;
    i.mi.dwExtraInfo = 0;
    i.mi.mouseData = 0;
    SEND(-4, 0)
    SEND(+4, 0)
    SEND(0, -4)
    SEND(0, +4)
    SetCursorPos(100, 100);
    GetCursorPos(&pt);
    fprintf(stderr, "Moved cursor to 100-100 cur(%ld %ld)\n", pt.x, pt.y);
    i.mi.dwFlags = MOUSEEVENTF_MOVE;
    SEND(-4, 0)
    i.mi.dwFlags |= MOUSEEVENTF_ABSOLUTE;
    send_abs(-10, 0, &i, &pt);
    send_abs(+10, 0, &i, &pt);

    /* Restopre position */
    SetCursorPos(ptorg.x, ptorg.y);
}

void test1(void)
{
    HHOOK hook;

    hook = SetWindowsHookExA(WH_MOUSE_LL, hook_proc, g_hInstance, 0);
    send_input();
    UnhookWindowsHookEx(hook);
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message) 
    {
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                     LPSTR lpCmdLine, int nCmdShow)
{
    WNDCLASSEX wcex;
    HWND hwnd;

    g_hInstance = hInstance;
    wcex.cbSize         = sizeof(WNDCLASSEX);
    wcex.style          = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = (WNDPROC)WndProc;
    wcex.cbClsExtra     = 0;
    wcex.cbWndExtra     = 0;
    wcex.hInstance      = hInstance;
    wcex.hIcon          = NULL;
    wcex.hCursor        = LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName   = NULL;
    wcex.lpszClassName  = "MainWindow";
    wcex.hIconSm        = NULL;
    RegisterClassEx(&wcex);


    hwnd = CreateWindow("MainWindow", "Title", WS_OVERLAPPEDWINDOW,
                        CW_USEDEFAULT, 0, 200, 200, NULL, NULL, NULL, NULL);
    ShowWindow(hwnd, SW_SHOW);

    test1();

    DestroyWindow(hwnd);
    return 0;
}