#include <u.h>
#include <X11/X.h>
#include <X11/Xatom.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <libc.h>
#include <ctype.h>

AUTOLIB(X11);

typedef struct Rectangle Rectangle;
struct Rectangle {
  struct {
    int x;
    int y;
  } min, max;
};
#define Dx(r) ((r).max.x - (r).min.x)
#define Dy(r) ((r).max.y - (r).min.y)

typedef struct Win Win;
struct Win {
  Window xw;
  int x;
  int y;
  int dx;
  int dy;
  char* class;
  char* instance;
  char* name;
  char* iconname;
};

Display* dpy;
Window root;

Win* w;
int nw;

void getinfo(void);
void listwindows(void);
int parsewinsize(char*, Rectangle*, int*, int*, int*);
void shove(char*, char*);

void usage(void) {
  fprint(2, "usage: xshove [window rectangle]\n");
  exits("usage");
}

void main(int argc, char** argv) {
  int screen;

  screen = 0;
  ARGBEGIN {
    case 's':
      screen = atoi(EARGF(usage()));
      break;
    default:
      usage();
      break;
  }
  ARGEND

  dpy = XOpenDisplay("");
  if (dpy == nil)
    sysfatal("open display: %r");

  root = RootWindow(dpy, screen);
  getinfo();

  if (argc == 0) {
    listwindows();
    exits(0);
  }
  if (argc != 2)
    usage();
  shove(argv[0], argv[1]);
  exits(0);
}

char* getproperty(Window w, Atom a) {
  uchar* p;
  int fmt;
  Atom type;
  ulong n, dummy;

  n = 100;
  p = nil;
  XGetWindowProperty(
    dpy,
    w,
    a,
    0,
    100L,
    0,
    AnyPropertyType,
    &type,
    &fmt,
    &n,
    &dummy,
    &p);
  if (p == nil || *p == 0)
    return nil;
  return strdup((char*)p);
}

Window findname(Window w) {
  int i;
  uint nxwin;
  Window dw1, dw2, *xwin;

  if (getproperty(w, XA_WM_NAME))
    return w;
  if (!XQueryTree(dpy, w, &dw1, &dw2, &xwin, &nxwin))
    return 0;
  for (i = 0; i < nxwin; i++)
    if ((w = findname(xwin[i])) != 0)
      return w;
  return 0;
}

void getinfo(void) {
  int i;
  uint nxwin;
  Window dw1, dw2, *xwin;
  XClassHint class;
  XWindowAttributes attr;

  if (!XQueryTree(dpy, root, &dw1, &dw2, &xwin, &nxwin))
    return;
  w = mallocz(nxwin * sizeof w[0], 1);
  if (w == 0)
    sysfatal("malloc: %r");

  Win* ww = w;
  for (i = 0; i < nxwin; i++) {
    memset(&attr, 0, sizeof attr);
    xwin[i] = findname(xwin[i]);
    if (xwin[i] == 0)
      continue;
    XGetWindowAttributes(dpy, xwin[i], &attr);
    if (
      attr.width <= 0 || attr.override_redirect || attr.map_state != IsViewable)
      continue;
    ww->xw = xwin[i];
    ww->x = attr.x;
    ww->y = attr.y;
    ww->dx = attr.width;
    ww->dy = attr.height;
    XTranslateCoordinates(dpy, ww->xw, root, 0, 0, &ww->x, &ww->y, &dw1);
    if (XGetClassHint(dpy, ww->xw, &class)) {
      ww->class = strdup(class.res_class);
      ww->instance = strdup(class.res_name);
    }
    ww->iconname = getproperty(ww->xw, XA_WM_ICON_NAME);
    ww->name = getproperty(ww->xw, XA_WM_NAME);
    ww++;
  }
  nw = ww - w;
}

void listwindows(void) {
  int i;

  for (i = 0; i < nw; i++) {
    Win* ww = &w[i];
    char rect[50];
    snprint(
      rect,
      sizeof rect,
      "%d,%d,%d,%d",
      ww->x,
      ww->y,
      ww->x + ww->dx,
      ww->y + ww->dy);
    print("%08x %-20s %-10s %s\n", (uint)ww->xw, rect, ww->instance, ww->class);
  }
}

void shove(char* name, char* geom) {
  int i;
  int isdelta, havemin, havesize;
  int old, new;
  Rectangle r;

  if (parsewinsize(geom, &r, &isdelta, &havemin, &havesize) < 0)
    sysfatal("bad window spec: %s", name);

  old = 0;
  new = 1;
  if (isdelta) {
    old = 1;
    new = isdelta;
  }
  for (i = 0; i < nw; i++) {
    Win* ww = &w[i];
    if (
      ww->instance && strstr(ww->instance, name) ||
      ww->class && strstr(ww->class, name)) {
      int value_mask;
      XWindowChanges e;

      memset(&e, 0, sizeof e);
      if (havemin) {
        e.x = old * ww->x + new* r.min.x;
        e.y = old * ww->y + new* r.min.y;
      } else {
        e.x = ww->x;
        e.y = ww->y;
      }
      if (havesize) {
        e.width = old * ww->dx + new* Dx(r);
        e.height = old * ww->dy + new* Dy(r);
      } else {
        e.width = ww->dx;
        e.height = ww->dy;
      }
      value_mask = CWX | CWY | CWWidth | CWHeight;
      XConfigureWindow(dpy, ww->xw, value_mask, &e);
      XFlush(dpy);
    }
  }
}

int parsewinsize(
  char* s, Rectangle* r, int* isdelta, int* havemin, int* havesize) {
  char c, *os;
  int i, j, k, l;

  os = s;
  if (*s == '-') {
    s++;
    *isdelta = -1;
  } else if (*s == '+') {
    s++;
    *isdelta = 1;
  } else
    *isdelta = 0;
  *havemin = 0;
  *havesize = 0;
  memset(r, 0, sizeof *r);
  if (!isdigit((uchar)*s))
    goto oops;
  i = strtol(s, &s, 0);
  if (*s == 'x') {
    s++;
    if (!isdigit((uchar)*s))
      goto oops;
    j = strtol(s, &s, 0);
    r->max.x = i;
    r->max.y = j;
    *havesize = 1;
    if (*s == 0)
      return 0;
    if (*s != '@')
      goto oops;

    s++;
    if (!isdigit((uchar)*s))
      goto oops;
    i = strtol(s, &s, 0);
    if (*s != ',' && *s != ' ')
      goto oops;
    s++;
    if (!isdigit((uchar)*s))
      goto oops;
    j = strtol(s, &s, 0);
    if (*s != 0)
      goto oops;
    r->min.x += i;
    r->max.x += i;
    r->min.y += j;
    r->max.y += j;
    *havesize = 1;
    *havemin = 1;
    return 0;
  }

  c = *s;
  if (c != ' ' && c != ',')
    goto oops;
  s++;
  if (!isdigit((uchar)*s))
    goto oops;
  j = strtol(s, &s, 0);
  if (*s == 0) {
    r->min.x = i;
    r->min.y = j;
    *havemin = 1;
    return 0;
  }
  if (*s != c)
    goto oops;
  s++;
  if (!isdigit((uchar)*s))
    goto oops;
  k = strtol(s, &s, 0);
  if (*s != c)
    goto oops;
  s++;
  if (!isdigit((uchar)*s))
    goto oops;
  l = strtol(s, &s, 0);
  if (*s != 0)
    goto oops;
  r->min.x = i;
  r->min.y = j;
  r->max.x = k;
  r->max.y = l;
  *havemin = 1;
  *havesize = 1;
  return 0;

oops:
  werrstr("bad syntax in window size '%s'", os);
  return -1;
}