// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
// SPDX-License-Identifier: GPL-3.0-or-later

#include "commands_native.h"
#include <X11/Xatom.h>
#include <X11/Xutil.h>
#include <string.h>

static int steam_active_window(Display *display, Window *window) {
    Atom type; int format;
    unsigned long count, remaining;
    unsigned char *data = NULL;
    int known = XGetWindowProperty(display, DefaultRootWindow(display), XInternAtom(display, "_NET_ACTIVE_WINDOW", False),
                                   0, 1, False, XA_WINDOW, &type, &format, &count, &remaining, &data) == Success &&
        data != NULL && type == XA_WINDOW && format == 32 && count == 1;
    if (known) *window = ((Window *)data)[0];
    if (data != NULL) XFree(data);
    return known;
}

static int steam_window_pid(Display *display, Window window) {
    Atom type; int format;
    unsigned long count, remaining;
    unsigned char *data = NULL;
    int pid = 0;
    if (XGetWindowProperty(display, window, XInternAtom(display, "_NET_WM_PID", False),
                           0, 1, False, XA_CARDINAL, &type, &format, &count,
                           &remaining, &data) == Success && data != NULL &&
        type == XA_CARDINAL && format == 32 && count == 1) {
        pid = (int)((unsigned long *)data)[0];
    }
    if (data != NULL) XFree(data);
    return pid;
}

static int steam_wrapper(Display *display, Window window) {
    XClassHint hint = {0};
    int matches = XGetClassHint(display, window, &hint) &&
        hint.res_name != NULL && hint.res_class != NULL &&
        strcmp(hint.res_name, "steamwebhelper") == 0 && strcmp(hint.res_class, "steam") == 0;
    if (hint.res_name != NULL) XFree(hint.res_name);
    if (hint.res_class != NULL) XFree(hint.res_class);
    return matches;
}

static int steam_browser_child(Display *display, Window wrapper, int pid, Window child) {
    XWindowAttributes attributes;
    if (child == None || child == PointerRoot || child == wrapper ||
        !XGetWindowAttributes(display, child, &attributes) || attributes.map_state != IsViewable ||
        attributes.class != InputOutput || steam_window_pid(display, child) != pid) return 0;
    for (int depth = 0; depth < 32; depth++) {
        Window root, parent, *children = NULL;
        unsigned int count;
        if (!XQueryTree(display, child, &root, &parent, &children, &count)) return 0;
        if (children != NULL) XFree(children);
        if (parent == wrapper) return 1;
        if (parent == None || parent == root) return 0;
        child = parent;
    }
    return 0;
}

CommandFocusSample cthulhu_read_command_focus(Display *display, int steam_enabled) {
    CommandFocusSample result = {0};
    SteamFocusSample *sample = &result.steam;
    cthulhu_x11_begin_read(display);
    result.xterm = cthulhu_focus_metadata_unchecked(display, steam_enabled ? sample : NULL);
    if (sample->steam) {
        sample->pid = steam_window_pid(display, sample->window);
        sample->steam = sample->pid > 0;
        int revert;
        XGetInputFocus(display, &sample->focus, &revert);
        if (sample->steam) sample->innerFocus = steam_browser_child(display, sample->window, sample->pid, sample->focus);
    }
    if (cthulhu_x11_end_read(display)) result = (CommandFocusSample){0};
    return result;
}

int cthulhu_restore_steam_focus(Display *display, Window wrapper, int pid, Window target) {
    cthulhu_x11_begin_read(display);
    int restored = 0, revert;
    Window focus, active = None;
    XGetInputFocus(display, &focus, &revert);
    char heldKeys[32];
    XQueryKeymap(display, heldKeys);
    int keyHeld = 0;
    for (int i = 0; i < 32; i++) keyHeld |= heldKeys[i];
    if (!keyHeld && focus == wrapper && steam_active_window(display, &active) && active == wrapper &&
        steam_wrapper(display, wrapper) &&
        steam_window_pid(display, wrapper) == pid && steam_browser_child(display, wrapper, pid, target)) {
        // Recheck foreground immediately before changing input focus: cached
        // children must never pull keyboard input out of a different client.
        if (steam_active_window(display, &active) && active == wrapper) {
            XGetInputFocus(display, &focus, &revert);
            if (focus == wrapper) {
                XSetInputFocus(display, target, RevertToParent, CurrentTime);
                XSync(display, False);
                XGetInputFocus(display, &focus, &revert);
                restored = focus == target;
            }
        }
    }
    if (cthulhu_x11_end_read(display)) restored = 0;
    return restored;
}