func NewXHandle(display string) (*xhandle, error) {
	c, err := xgb.NewConnDisplay(display)
	if err != nil {
		return nil, err
	}

	s := xproto.Setup(c)
	screen := s.DefaultScreen(c)

	kb, err := NewKeyboard(s, c)
	if err != nil {
		return nil, err
	}

	h := &xhandle{
		conn:     c,
		root:     screen.Root,
		Events:   make([]Event, 0, 1000),
		EvtsLck:  &sync.RWMutex{},
		keyboard: kb,
		Keys:     make(map[int]map[xproto.Window]map[Input][]Key),
		KeysLck:  &sync.RWMutex{},
	}

	return h, nil
}

func newHeads(X *xgb.Conn) heads {
	var primaryHead *head
	var primaryOutput randr.Output

	root := xproto.Setup(X).DefaultScreen(X).Root
	resources, err := randr.GetScreenResourcesCurrent(X, root).Reply()
	if err != nil {
		log.Fatalf("Could not get screen resources: %s.", err)
	}

	primaryOutputReply, _ := randr.GetOutputPrimary(X, root).Reply()
	if primaryOutputReply != nil {
		primaryOutput = primaryOutputReply.Output
	}

	hds := make([]head, 0, len(resources.Outputs))
	off := make([]string, 0)
	disconnected := make([]string, 0)
	for i, output := range resources.Outputs {
		oinfo, err := randr.GetOutputInfo(X, output, 0).Reply()
		if err != nil {
			log.Fatalf("Could not get output info for screen %d: %s.", i, err)
		}
		outputName := string(oinfo.Name)

		if oinfo.Connection != randr.ConnectionConnected {
			disconnected = append(disconnected, outputName)
			continue
		}
		if oinfo.Crtc == 0 {
			off = append(off, outputName)
			continue
		}

		crtcinfo, err := randr.GetCrtcInfo(X, oinfo.Crtc, 0).Reply()
		if err != nil {
			log.Fatalf("Could not get crtc info for screen (%d, %s): %s.",
				i, outputName, err)
		}

		head := newHead(output, outputName, crtcinfo)
		if output == primaryOutput {
			primaryHead = &head
		}
		hds = append(hds, head)
	}
	if primaryHead == nil && len(hds) > 0 {
		tmp := hds[0]
		primaryHead = &tmp
	}

	hdsPrim := heads{
		primary:      primaryHead,
		heads:        hds,
		off:          off,
		disconnected: disconnected,
	}
	sort.Sort(hdsPrim)
	return hdsPrim
}

// Lock grabs the keyboard and pointer locking the X11 display
func Lock(X *xgb.Conn) error {
	screen := xproto.Setup(X).DefaultScreen(X)

	passEventsToOwner := false
	kbCookie := xproto.GrabKeyboard(X, passEventsToOwner, screen.Root, xproto.TimeCurrentTime, xproto.GrabModeAsync, xproto.GrabModeAsync)
	kbReply, err := kbCookie.Reply()
	if err != nil {
		return err
	}
	if kbReply.Status != xproto.GrabStatusSuccess {
		return fmt.Errorf("GrabKeyboard status %v", grabStatus(kbReply.Status))
	}

	ptrCookie := xproto.GrabPointer(X, passEventsToOwner, screen.Root, 0, xproto.GrabModeAsync, xproto.GrabModeAsync, xproto.AtomNone, xproto.AtomNone, xproto.TimeCurrentTime)

	ptrReply, err := ptrCookie.Reply()
	if err != nil {
		xproto.UngrabKeyboard(X, xproto.TimeCurrentTime)
		return err
	}
	if ptrReply.Status != xproto.GrabStatusSuccess {
		return fmt.Errorf("GrabPointer status %v", grabStatus(kbReply.Status))
	}

	return nil
}

func getPrimaryScreenBestResolution() (w uint16, h uint16) {
	// if connect to x failed, just return 1024x768
	w, h = 1024, 768

	XU, err := xgbutil.NewConn()
	if err != nil {
		return
	}
	err = randr.Init(XU.Conn())
	if err != nil {
		return
	}
	_, err = randr.QueryVersion(XU.Conn(), 1, 4).Reply()
	if err != nil {
		return
	}
	Root := xproto.Setup(XU.Conn()).DefaultScreen(XU.Conn()).Root
	resources, err := randr.GetScreenResources(XU.Conn(), Root).Reply()
	if err != nil {
		return
	}

	bestModes := make([]uint32, 0)
	for _, output := range resources.Outputs {
		reply, err := randr.GetOutputInfo(XU.Conn(), output, 0).Reply()
		if err == nil && reply.NumModes > 1 {
			bestModes = append(bestModes, uint32(reply.Modes[0]))
		}
	}

	w, h = 0, 0
	for _, m := range resources.Modes {
		for _, id := range bestModes {
			if id == m.Id {
				bw, bh := m.Width, m.Height
				if w == 0 || h == 0 {
					w, h = bw, bh
				} else if uint32(bw)*uint32(bh) < uint32(w)*uint32(h) {
					w, h = bw, bh
				}
			}
		}
	}

	if w == 0 || h == 0 {
		// get resource failed, use root window's geometry
		rootRect := xwindow.RootGeometry(XU)
		w, h = uint16(rootRect.Width()), uint16(rootRect.Height())
	}

	if w == 0 || h == 0 {
		w, h = 1024, 768 // default value
	}

	logger.Debugf("primary screen's best resolution is %dx%d", w, h)
	return
}

func Load(c *xgb.Conn) error {
	ctxs = make(map[string]*gcontext)
	scr := xproto.Setup(c).DefaultScreen(c)
	err := loadGCS(c, scr)
	if err != nil {
		return err
	}
	return nil
}

func (m *Mouse) Move(args *MoveArgs, reply *int) error {
	//fmt.Printf("%#v\n", args)
	screen := xproto.Setup(m.x11).DefaultScreen(m.x11)
	cookie := xtest.FakeInputChecked(m.x11, xproto.MotionNotify, 0, 0, screen.Root, int16(args.X), int16(args.Y), 0)
	if cookie.Check() != nil {
		fmt.Println("FakeInput failed")
	}

	return nil
}

func ScreenRect() (image.Rectangle, error) {
	c, err := xgb.NewConn()
	if err != nil {
		return image.Rectangle{}, err
	}
	defer c.Close()

	screen := xproto.Setup(c).DefaultScreen(c)
	x := screen.WidthInPixels
	y := screen.HeightInPixels

	return image.Rect(0, 0, int(x), int(y)), nil
}

func main() {
	X, err := xgb.NewConn()
	if err != nil {
		log.Fatal(err)
	}

	// Get the window id of the root window.
	setup := xproto.Setup(X)
	root := setup.DefaultScreen(X).Root

	// Get the atom id (i.e., intern an atom) of "_NET_ACTIVE_WINDOW".
	aname := "_NET_ACTIVE_WINDOW"
	activeAtom, err := xproto.InternAtom(X, true, uint16(len(aname)),
		aname).Reply()
	if err != nil {
		log.Fatal(err)
	}

	// Get the atom id (i.e., intern an atom) of "_NET_WM_NAME".
	aname = "_NET_WM_NAME"
	nameAtom, err := xproto.InternAtom(X, true, uint16(len(aname)),
		aname).Reply()
	if err != nil {
		log.Fatal(err)
	}

	// Get the actual value of _NET_ACTIVE_WINDOW.
	// Note that 'reply.Value' is just a slice of bytes, so we use an
	// XGB helper function, 'Get32', to pull an unsigned 32-bit integer out
	// of the byte slice. We then convert it to an X resource id so it can
	// be used to get the name of the window in the next GetProperty request.
	reply, err := xproto.GetProperty(X, false, root, activeAtom.Atom,
		xproto.GetPropertyTypeAny, 0, (1<<32)-1).Reply()
	if err != nil {
		log.Fatal(err)
	}
	windowId := xproto.Window(xgb.Get32(reply.Value))
	fmt.Printf("Active window id: %X\n", windowId)

	// Now get the value of _NET_WM_NAME for the active window.
	// Note that this time, we simply convert the resulting byte slice,
	// reply.Value, to a string.
	reply, err = xproto.GetProperty(X, false, windowId, nameAtom.Atom,
		xproto.GetPropertyTypeAny, 0, (1<<32)-1).Reply()
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("Active window name: %s\n", string(reply.Value))
}

func (b *brightness) adjust(Xu *xgbutil.XUtil, increase bool) error {
	X := Xu.Conn()
	root := xproto.Setup(X).DefaultScreen(X).Root
	screens, err := randr.GetScreenResources(X, root).Reply()
	if err != nil {
		return fmt.Errorf("getting screen: %v", err)
	}

	for _, output := range screens.Outputs {
		query, err := randr.QueryOutputProperty(X, output, b.prop).Reply()
		if err != nil {
			if _, ok := err.(xproto.NameError); ok {
				// this output has no backlight
				continue
			}
			return fmt.Errorf("query backlight: %v", err)
		}
		if !query.Range {
			return errors.New("backlight brightness range not specified")
		}
		if len(query.ValidValues) != 2 {
			return fmt.Errorf("expected min and max, got: %v", query.ValidValues)
		}
		min, max := query.ValidValues[0], query.ValidValues[1]
		// log.Printf("backlight range: %d .. %d", min, max)

		get, err := randr.GetOutputProperty(X, output, b.prop, xproto.AtomNone, 0, 4, false, false).Reply()
		if err != nil {
			return fmt.Errorf("get backlight property: %v", err)
		}
		if get.Type != xproto.AtomInteger ||
			get.NumItems != 1 ||
			get.Format != 32 {
			return fmt.Errorf("backlight property value looks wrong")
		}
		old := *(*int32)(unsafe.Pointer(&get.Data[0]))
		// log.Printf("backlight data: %d", old)

		bri := delta5(old, min, max, increase)

		data := (*[4]byte)(unsafe.Pointer(&bri))[:]
		if err := randr.ChangeOutputPropertyChecked(X, output, b.prop, xproto.AtomInteger, 32, xproto.PropModeReplace, 1, data).Check(); err != nil {
			return err
		}
	}
	return nil
}

func main() {

	//	os.Setenv("DISPLAY", "localhost:6080")

	c, err := xgb.NewConn()
	if err != nil {
		fmt.Println(err)
		return
	}
	screen := xproto.Setup(c).DefaultScreen(c)

	rect := image.Rect(0, 0, int(screen.WidthInPixels), int(screen.HeightInPixels))

	x, y := rect.Dx(), rect.Dy()

	xImg, err := xproto.GetImage(c,
		xproto.ImageFormatZPixmap,
		xproto.Drawable(screen.Root),
		int16(rect.Min.X),
		int16(rect.Min.Y),
		uint16(x),
		uint16(y),
		0xffffffff).Reply()

	if err != nil {
		fmt.Println("Error: %s\r\n", err)
	}

	data := xImg.Data
	for i := 0; i < len(data); i += 4 {
		data[i], data[i+2], data[i+3] = data[i+2], data[i], 255
	}

	img := &image.RGBA{
		data, 4 * x, image.Rect(0, 0, x, y)}

	z.FcheckParents("screen")
	f := z.FileW("screen")
	defer f.Close()

	png := jpeg.Encode(f, img, &jpeg.Options{90})

	fmt.Printf("End with png: %v", png)
}

func (logger *WindowLogger) getCurWindowTitle() (name string, err error) {
	// Get the window id of the root window.
	setup := xproto.Setup(logger.X11Connection)
	root := setup.DefaultScreen(logger.X11Connection).Root

	// Get the atom id (i.e., intern an atom) of "_NET_ACTIVE_WINDOW".
	aname := "_NET_ACTIVE_WINDOW"
	activeAtom, err := xproto.InternAtom(logger.X11Connection, true, uint16(len(aname)),
		aname).Reply()
	if err != nil {
		return "", err
	}

	// Get the atom id (i.e., intern an atom) of "_NET_WM_NAME".
	aname = "_NET_WM_NAME"
	nameAtom, err := xproto.InternAtom(logger.X11Connection, true, uint16(len(aname)),
		aname).Reply()
	if err != nil {
		return "", err
	}

	// Get the actual value of _NET_ACTIVE_WINDOW.
	// Note that 'reply.Value' is just a slice of bytes, so we use an
	// XGB helper function, 'Get32', to pull an unsigned 32-bit integer out
	// of the byte slice. We then convert it to an X resource id so it can
	// be used to get the name of the window in the next GetProperty request.
	reply, err := xproto.GetProperty(logger.X11Connection, false, root, activeAtom.Atom,
		xproto.GetPropertyTypeAny, 0, (1<<32)-1).Reply()
	if err != nil {
		return "", err
	}
	windowId := xproto.Window(xgb.Get32(reply.Value))

	// Now get the value of _NET_WM_NAME for the active window.
	// Note that this time, we simply convert the resulting byte slice,
	// reply.Value, to a string.
	reply, err = xproto.GetProperty(logger.X11Connection, false, windowId, nameAtom.Atom,
		xproto.GetPropertyTypeAny, 0, (1<<32)-1).Reply()
	if err != nil {
		return "", err
	}
	return string(reply.Value), nil
}

func newScreenImpl(xc *xgb.Conn) (*screenImpl, error) {
	s := &screenImpl{
		xc:      xc,
		xsi:     xproto.Setup(xc).DefaultScreen(xc),
		buffers: map[shm.Seg]*bufferImpl{},
		uploads: map[uint16]completion{},
		windows: map[xproto.Window]*windowImpl{},
	}
	if err := s.initAtoms(); err != nil {
		return nil, err
	}
	if err := s.initPictformats(); err != nil {
		return nil, err
	}
	if err := s.initWindow32(); err != nil {
		return nil, err
	}
	go s.run()
	return s, nil
}

func main() {

	var serve *bool = flag.Bool("serve", false, "Listen for connections")

	flag.Usage = usage
	flag.Parse()

	if remote := os.Getenv("SSH_CONNECTION"); remote == "" && len(flag.Args()) != 0 {
		invoked_as := os.Args[0]
		actual_binary, err := os.Readlink("/proc/self/exe")
		if err != nil {
			log.Panic("/proc/self/exe doesn't exist!")
		}
		log.Print("Invoked as: '", invoked_as, "' (actual=", actual_binary, ")")
		log.Panic("Not yet implemented: Would have run locally")
		return
	}

	c, err := xgb.NewConn()
	if err != nil {
		log.Panic("cannot connect: %v\n", err)
	}
	s := xproto.Setup(c).DefaultScreen(c)

	rl_execute_reply, err := xproto.InternAtom(c, false, uint16(len(atomname)), atomname).Reply()
	if err != nil {
		panic(err)
	}
	rl_execute_atom := rl_execute_reply.Atom

	if *serve {
		//log.Printf("c = %v, s = %v, a = %v", c, s, rl_execute_atom)
		start_server(c, s, rl_execute_atom)
	} else {
		if len(flag.Args()) == 0 {
			usage()
		}
		connect(c, s, rl_execute_atom, fixup_args(flag.Args()))
	}
}

func subscribeXEvents(ch chan<- Event, done <-chan struct{}) {
	X, err := xgb.NewConn()
	if err != nil {
		ch <- Event{Error: err}
		return
	}

	defer X.Close()
	if err = randr.Init(X); err != nil {
		ch <- Event{Error: err}
		return
	}

	root := xproto.Setup(X).DefaultScreen(X).Root

	eventMask := randr.NotifyMaskScreenChange |
		randr.NotifyMaskCrtcChange |
		randr.NotifyMaskOutputChange |
		randr.NotifyMaskOutputProperty

	err = randr.SelectInputChecked(X, root, uint16(eventMask)).Check()
	if err != nil {
		ch <- Event{Error: err}
		return
	}

	for {
		ev, err := X.WaitForEvent()
		select {
		case ch <- Event{Event: ev, Error: err}:
		case <-time.After(eventSendTimeout):
			continue
		case <-done:
			return
		}
		if err != nil {
			log.Fatal(err)
		}
	}
}

func CaptureRect(rect image.Rectangle) (*image.RGBA, error) {
	c, err := xgb.NewConn()
	if err != nil {
		return nil, err
	}
	defer c.Close()

	screen := xproto.Setup(c).DefaultScreen(c)
	x, y := rect.Dx(), rect.Dy()
	xImg, err := xproto.GetImage(c, xproto.ImageFormatZPixmap, xproto.Drawable(screen.Root), int16(rect.Min.X), int16(rect.Min.Y), uint16(x), uint16(y), 0xffffffff).Reply()
	if err != nil {
		return nil, err
	}

	data := xImg.Data
	for i := 0; i < len(data); i += 4 {
		data[i], data[i+2], data[i+3] = data[i+2], data[i], 255
	}

	img := &image.RGBA{data, 4 * x, image.Rect(0, 0, x, y)}
	return img, nil
}

func Open(c *xgb.Conn, ctx, title, text string) (*Window, error) {
	gc, ok := ctxs[ctx]
	if !ok {
		return nil, BadContextError(ctx)
	}

	scr := xproto.Setup(c).DefaultScreen(c)
	wdwid, err := xproto.NewWindowId(c)
	if err != nil {
		return nil, err
	}

	lines := cutLines(c, gc.width-2*gc.border, gc.font, text)
	height := uint32(len(lines)) * gc.fontHeight

	var mask uint32 = xproto.CwBackPixel | xproto.CwOverrideRedirect | xproto.CwEventMask
	values := make([]uint32, 3)
	values[0] = scr.WhitePixel
	values[1] = 1
	values[2] = xproto.EventMaskExposure
	err = xproto.CreateWindowChecked(c, xproto.WindowClassCopyFromParent, wdwid, scr.Root,
		0, 0, uint16(gc.width), uint16(height+2*gc.border), 1,
		xproto.WindowClassInputOutput, scr.RootVisual,
		mask, values).Check()
	if err != nil {
		return nil, err
	}
	xproto.ChangeProperty(c, xproto.PropModeReplace, wdwid,
		xproto.AtomWmName, xproto.AtomString,
		8, uint32(len(title)), []byte(title))

	var wdw Window
	wdw.id = wdwid
	wdw.conn = c
	wdw.lines = lines
	wdw.gc = gc
	wdw.geom = types.Geometry{0, 0, int32(gc.width), int32(height + 2*gc.border)}
	return &wdw, nil
}

func default1() {

	X, err := xgb.NewConn()
	if err != nil {
		fmt.Println(err)
		return
	}

	wid, _ := xproto.NewWindowId(X)
	screen := xproto.Setup(X).DefaultScreen(X)
	xproto.CreateWindow(X, screen.RootDepth, wid, screen.Root,
		0, 0, 500, 500, 0,
		xproto.WindowClassInputOutput, screen.RootVisual,
		xproto.CwBackPixel|xproto.CwEventMask,
		[]uint32{
			0xffffffff,
			xproto.EventMaskStructureNotify |
				xproto.EventMaskKeyPress |
				xproto.EventMaskKeyRelease})

	xproto.MapWindow(X, wid)
	for {
		ev, xerr := X.WaitForEvent()
		if ev == nil && xerr == nil {
			fmt.Println("Both event and error are nil. Exiting...")
			return
		}

		if ev != nil {
			fmt.Println("Event: %s\r\n", ev)
		}
		if xerr != nil {
			fmt.Println("Error: %s\r\n", xerr)
		}

	}

}

func Focused(c *xgb.Conn) uint32 {
	incookie := xproto.GetInputFocus(c)
	rep, err := incookie.Reply()
	if err != nil {
		return 0
	}
	win := rep.Focus

	trcookie := xproto.TranslateCoordinates(c, win,
		xproto.Setup(c).DefaultScreen(c).Root,
		0, 0)
	att, err := trcookie.Reply()
	if err != nil {
		return 0
	}
	x, y := int32(att.DstX), int32(att.DstY)

	for i, size := range sizes {
		if size.X <= x && size.X+size.W >= x && size.Y <= y && size.Y+size.H >= y {
			return uint32(i)
		}
	}
	return 0
}

func setStatus(status []byte, X *xgb.Conn) {
	screen := xproto.Setup(X).DefaultScreen(X)
	fmt.Println(string(status))
	setWindowTitle(status, X, screen.Root)
}

func main() {
	X, _ := xgb.NewConn()

	// Every extension must be initialized before it can be used.
	err := randr.Init(X)
	if err != nil {
		log.Fatal(err)
	}

	// Get the root window on the default screen.
	root := xproto.Setup(X).DefaultScreen(X).Root

	// Gets the current screen resources. Screen resources contains a list
	// of names, crtcs, outputs and modes, among other things.
	resources, err := randr.GetScreenResources(X, root).Reply()
	if err != nil {
		log.Fatal(err)
	}

	// Iterate through all of the outputs and show some of their info.
	for _, output := range resources.Outputs {
		info, err := randr.GetOutputInfo(X, output, 0).Reply()
		if err != nil {
			log.Fatal(err)
		}

		bestMode := info.Modes[0]
		for _, mode := range resources.Modes {
			if mode.Id == uint32(bestMode) {
				fmt.Printf("Width: %d, Height: %d\n", mode.Width, mode.Height)
			}
		}
	}

	fmt.Println("\n")

	// Iterate through all of the crtcs and show some of their info.
	for _, crtc := range resources.Crtcs {
		info, err := randr.GetCrtcInfo(X, crtc, 0).Reply()
		if err != nil {
			log.Fatal(err)
		}
		fmt.Printf("X: %d, Y: %d, Width: %d, Height: %d\n",
			info.X, info.Y, info.Width, info.Height)
	}

	// Tell RandR to send us events. (I think these are all of them, as of 1.3.)
	err = randr.SelectInputChecked(X, root,
		randr.NotifyMaskScreenChange|
			randr.NotifyMaskCrtcChange|
			randr.NotifyMaskOutputChange|
			randr.NotifyMaskOutputProperty).Check()
	if err != nil {
		log.Fatal(err)
	}

	// Listen to events and just dump them to standard out.
	// A more involved approach will have to read the 'U' field of
	// RandrNotifyEvent, which is a union (really a struct) of type
	// RanrNotifyDataUnion.
	for {
		ev, err := X.WaitForEvent()
		if err != nil {
			log.Fatal(err)
		}
		fmt.Println(ev)
	}
}