#include <stdio.h>
#include <stdlib.h>

#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/select.h>
#include <sys/time.h>
#include <sys/types.h>

#include <X11/X.h>
#include <X11/Xlib.h>

#include <linux/joystick.h>

int j2m[] = {
    Button1, Button2, Button3, Button4, Button5
};
int j2m_size = sizeof(j2m)/sizeof(int);

int main(int argc, char* argv[]) {
    Display* display;
    Window root;
    XEvent ev;
    XButtonEvent* be;
    int dev;
    int jx = 0, jy = 0;
    fd_set fds;

    display = XOpenDisplay((argc == 1) ? ":0" : argv[1]);
    root = XDefaultRootWindow(display);

    be = &ev.xbutton;

    dev = open("/dev/input/js0", O_RDONLY);
    if (dev == -1) {
        perror("open");
        return 1;
    }

    while (1) {
        int ret;
        int mx = 0, my = 0;
        struct timeval tv;

        tv.tv_sec = 0;
        tv.tv_usec = 10000;

        FD_ZERO(&fds);
        FD_SET(dev, &fds);

        /* in not linux system, it will run differently */
        while (ret = select(dev+1, &fds, NULL, NULL, &tv)) {
            struct js_event j;

            if (ret < 0) {
                perror("select");
                return 1;
            }

            read(dev, &j, sizeof(j));
            if (j.type == 0x02) {
                if (j.number == 0x00) {
                    jx = (j.value > 1000) - (j.value < -1000);
                }
                else if (j.number == 0x01) {
                    jy = (j.value > 1000) - (j.value < -1000);
                }
            }
            else if (j.type == 0x01) {
                int em;
                int d;
                Window child;

                if (j.number >= j2m_size) continue;
                if (j2m[j.number] == -1) continue;

                child = root;
                do {
                    be->window = child;
                    XQueryPointer(display, be->window, &be->root, &child,
                                  &be->x_root, &be->y_root, &be->x, &be->y,
                                  &be->state);
                } while (child);
                ev.type = (j.value) ? ButtonPress : ButtonRelease;
                em = (j.value) ? ButtonPressMask : ButtonReleaseMask;
                be->display = display;
                be->subwindow = None;
                be->time = CurrentTime;
                be->button = j2m[j.number];
                be->same_screen = True;

                XSendEvent(display, be->window, True, em, &ev);
                XFlush(display);
            }
        }
        jx += (jx > 0) - (jx < 0);
        jy += (jy > 0) - (jy < 0);
        if (jx > 0) mx += 5;
        if (jx > 30) mx += 10;
        if (jx < 0) mx -= 5;
        if (jx < -30) mx -= 10;
        if (jy > 0) my += 5;
        if (jy > 30) my += 10;
        if (jy < 0) my -= 5;
        if (jy < -30) my -= 10;

        if (mx || my) {
            XWarpPointer(display, None, None, 0, 0, 0, 0, mx, my);
            XFlush(display);
        }
    }

    close(dev);

    return 0;
}