// SPDX-License-Identifier: BSD-3-Clause
// xtest_move.c - drive the game with XTEST: hold forward + fire and tap
// left/right periodically so the captured footage has constant motion.
// Usage: xtest_move <display> <seconds>
#include <X11/Xlib.h>
#include <X11/keysym.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

extern int XTestFakeKeyEvent(Display *, unsigned int, int, unsigned long);

int main(int argc, char **argv)
{
    Display *d = XOpenDisplay(argc > 1 ? argv[1] : ":1");
    int secs = argc > 2 ? atoi(argv[2]) : 12;
    KeyCode kFwd, kFire, kLeft, kRight;
    int t;

    if (!d) {
        fprintf(stderr, "xtest_move: no display\n");
        return 1;
    }
    /* No WM on Xvfb: give the game window input focus ourselves. */
    {
        Window r, parent, *kids = NULL;
        unsigned int nk = 0;

        if (XQueryTree(d, DefaultRootWindow(d), &r, &parent, &kids, &nk)) {
            unsigned int i;

            for (i = 0; i < nk; i++) {
                char *nm = NULL;

                if (XFetchName(d, kids[i], &nm) && nm) {
                    int hit = strstr(nm, "Freedoom") || strstr(nm, "Doom") ||
                              strstr(nm, "gzdoom") || strstr(nm, "Outer");

                    XFree(nm);
                    if (hit) {
                        XSetInputFocus(d, kids[i], RevertToParent, CurrentTime);
                        fprintf(stderr, "xtest_move: focused 0x%lx\n",
                                (unsigned long)kids[i]);
                        break;
                    }
                }
            }
            if (kids)
                XFree(kids);
        }
    }
    kFwd = XKeysymToKeycode(d, XK_Up);
    kFire = XKeysymToKeycode(d, XK_space);
    kLeft = XKeysymToKeycode(d, XK_Left);
    kRight = XKeysymToKeycode(d, XK_Right);
    fprintf(stderr, "xtest_move: fwd=%d fire=%d left=%d right=%d\n",
            kFwd, kFire, kLeft, kRight);
    XTestFakeKeyEvent(d, kFwd, 1, 0);
    XTestFakeKeyEvent(d, kFire, 1, 0);
    XFlush(d);
    /* Continuous motion: rotate steadily (hold a turn key ~0.8 s, then
     * the other) while forward+fire stay held - every frame changes. */
    for (t = 0; t < secs * 10; t++) {
        KeyCode turn = (t & 8) ? kLeft : kRight;
        Window wr, wpar, *wk = NULL;
        unsigned int wnk = 0;

        /* Re-assert focus every tick: Xvfb has no WM, and any new X client
         * (the capture tool) can leave the game unfocused - GZDoom pauses
         * the game the moment SDL reports focus loss. */
        if (XQueryTree(d, DefaultRootWindow(d), &wr, &wpar, &wk, &wnk)) {
            unsigned int i;

            for (i = 0; i < wnk; i++) {
                char *nm = NULL;

                if (XFetchName(d, wk[i], &nm) && nm) {
                    int hit = strstr(nm, "Freedoom") || strstr(nm, "Outer") ||
                              strstr(nm, "Doom");

                    XFree(nm);
                    if (hit) {
                        XSetInputFocus(d, wk[i], RevertToParent,
                                       CurrentTime);
                        break;
                    }
                }
            }
            if (wk)
                XFree(wk);
        }
        XTestFakeKeyEvent(d, kLeft, 0, 0);
        XTestFakeKeyEvent(d, kRight, 0, 0);
        XTestFakeKeyEvent(d, turn, 1, 0);
        XFlush(d);
        usleep(100000);
    }
    XTestFakeKeyEvent(d, kLeft, 0, 0);
    XTestFakeKeyEvent(d, kRight, 0, 0);
    XTestFakeKeyEvent(d, kFwd, 0, 0);
    XTestFakeKeyEvent(d, kFire, 0, 0);
    XFlush(d);
    XCloseDisplay(d);
    fprintf(stderr, "xtest_move: done\n");
    return 0;
}