package xorg

/*
#cgo pkg-config: xres
#include "commands_native.h"
#include <X11/XKBlib.h>
*/
import "C"

func ActiveWindowIsXTerm() bool {
	return C.cthulhu_active_window_is_xterm() != 0
}

// Foreground is an immutable X11 client identity and its screen rectangle.
// Known with Window == 0 means no foreground client, not missing metadata.
type Foreground struct {
	Known  bool
	Window uint64
	PID    int
	// PropertyPID retains _NET_WM_PID for diagnostics. PID uses the X server's
	// local client identity when available, so Flatpak namespaces agree with AT-SPI.
	PropertyPID                             int
	X, Y, Width, Height                     int
	OuterX, OuterY, OuterWidth, OuterHeight int
	// Frame bounds come from the client's enclosing X11 window, independently
	// of _NET_FRAME_EXTENTS. Zero dimensions mean no unambiguous frame exists.
	FrameX, FrameY, FrameWidth, FrameHeight int
}

// ForegroundReader has no goroutine. Its native event-loop owner opens, reads,
// and closes it on that thread; no consumer performs X11 I/O.
type ForegroundReader struct {
	display                *C.Display
	clientPIDs             bool
	pidWindow              uint64
	propertyPID, clientPID int
}

func OpenForegroundReader() *ForegroundReader {
	display := C.XOpenDisplay(nil)
	if display == nil {
		return nil
	}
	return &ForegroundReader{display: display, clientPIDs: C.cthulhu_xres_client_pids_supported(display) != 0}
}
func (reader *ForegroundReader) Read() Foreground {
	if reader == nil {
		return Foreground{}
	}
	value := C.read_foreground(reader.display)
	window, propertyPID := uint64(value.window), int(value.pid)
	// The connection's owner also owns this one-client cache. Window departure
	// (including no foreground) or a changed property discards the old identity.
	// Resizing and ordinary input never trigger an extra server query.
	if window != reader.pidWindow || propertyPID != reader.propertyPID {
		reader.pidWindow, reader.propertyPID, reader.clientPID = window, propertyPID, 0
		if window != 0 && reader.clientPIDs {
			reader.clientPID = int(C.cthulhu_xres_client_pid(reader.display, C.Window(window)))
		}
	}
	pid := propertyPID
	if reader.clientPID > 0 {
		pid = reader.clientPID
	}
	return Foreground{Known: value.known != 0, Window: window, PID: pid, PropertyPID: propertyPID,
		X: int(value.x), Y: int(value.y), Width: int(value.width), Height: int(value.height), OuterX: int(value.outerX), OuterY: int(value.outerY), OuterWidth: int(value.outerWidth), OuterHeight: int(value.outerHeight),
		FrameX: int(value.frameX), FrameY: int(value.frameY), FrameWidth: int(value.frameWidth), FrameHeight: int(value.frameHeight)}
}
func (reader *ForegroundReader) Close() {
	if reader != nil {
		C.XCloseDisplay(reader.display)
		reader.display = nil
	}
}