#!/usr/bin/env python3
# PYTHON_ARGCOMPLETE_OK

"""
https://cgit.freedesktop.org/xorg/app/xrandr/tree/xrandr.c
"""

import ctypes
import ctypes.util

X_Time = ctypes.c_ulong
"""
#ifndef _XTYPEDEF_XID
#  define _XTYPEDEF_XID
#  ifndef _XSERVER64
typedef unsigned long XID;
#  else
typedef CARD32 XID;
#  endif
#endif
"""
X_XID = ctypes.c_ulong
"""
typedef XID RROutput;
"""
X_RROutput = X_XID
"""
typedef XID RRCrtc;
"""
X_RRCrtc = X_XID
""" /usr/include/X11/extensions/Xrandr.h
typedef XID RRMode;
"""
X_RRMode = X_XID
""" /usr/include/X11/extensions/randr.h
#define RR_Connected		0
"""
X_RR_Connected = 0
""" /usr/include/X11/extensions/randr.h
typedef unsigned short	Connection;
"""
X_Connection = ctypes.c_ushort
""" /usr/include/X11/extensions/randr.h
typedef unsigned short	SubpixelOrder;
"""
X_SubpixelOrder = ctypes.c_ushort


class X_XRRScreenResources(ctypes.Structure):

    """ /usr/include/X11/extensions/Xrandr.h
    typedef struct _XRRScreenResources {
        Time	timestamp;
        Time	configTimestamp;
        int		ncrtc;
        RRCrtc	*crtcs;
        int		noutput;
        RROutput	*outputs;
        int		nmode;
        XRRModeInfo	*modes;
    } XRRScreenResources;
    """
    _fields_ = [
        ('timestamp', X_Time),
        ('configTimestamp', X_Time),
        ('ncrtc', ctypes.c_int),
        ('crtcs', ctypes.POINTER(X_RRCrtc)),
        ('noutput', ctypes.c_int),
        ('outputs', ctypes.POINTER(X_RROutput)),
        ('nmode', ctypes.c_int),
        ('modes', ctypes.c_void_p),  # ctypes.POINTER(XRRModeInfo)
    ]


class X_XRROutputInfo(ctypes.Structure):

    """
    typedef struct _XRROutputInfo {
        Time	    timestamp;
        RRCrtc	    crtc;
        char	    *name;
        int		    nameLen;
        unsigned long   mm_width;
        unsigned long   mm_height;
        Connection	    connection;
        SubpixelOrder   subpixel_order;
        int		    ncrtc;
        RRCrtc	    *crtcs;
        int		    nclone;
        RROutput	    *clones;
        int		    nmode;
        int		    npreferred;
        RRMode	    *modes;
    } XRROutputInfo;
    """
    _fields_ = [
        ('timestamp', X_Time),
        ('crtc', X_RRCrtc),
        ('name', ctypes.c_char_p),
        ('nameLen', ctypes.c_int),
        ('mm_width', ctypes.c_ulong),
        ('mm_height', ctypes.c_ulong),
        ('connection', X_Connection),
        ('subpixel_order', X_SubpixelOrder),
        ('ncrtc', ctypes.c_int),
        ('crtcs', ctypes.POINTER(X_RRCrtc)),
        ('nclone', ctypes.c_int),
        ('clones', ctypes.POINTER(X_RROutput)),
        ('nmode', ctypes.c_int),
        ('npreferred', ctypes.c_int),
        ('modes', ctypes.POINTER(X_RRMode)),
    ]

X11 = ctypes.cdll.LoadLibrary("libX11.so")
Xrandr = ctypes.cdll.LoadLibrary("libXrandr.so")
Xrandr.XRRGetScreenResourcesCurrent.restype = \
    ctypes.POINTER(X_XRRScreenResources)
libc = ctypes.cdll.LoadLibrary(ctypes.util.find_library('c'))
"""
XRROutputInfo *
XRRGetOutputInfo (Display *dpy, XRRScreenResources *resources, RROutput output);
"""
Xrandr.XRRGetOutputInfo.restype = ctypes.POINTER(X_XRROutputInfo)


class RandrOutputInfo:

    def __init__(self,
                 xdisplay,
                 screen_resrcs: ctypes.POINTER(X_XRRScreenResources),
                 output: X_RROutput):
        self._p = Xrandr.XRRGetOutputInfo(xdisplay, screen_resrcs, output)

    def __del__(self):
        libc.free(self._p)

    @property
    def enabled(self):
        return self._p.contents.crtc != 0

    @property
    def connected(self):
        return self._p.contents.connection == X_RR_Connected

    @property
    def name(self):
        return self._p.contents.name.decode()


def get_xrandr_output_infos(xdisplay):
    screen_resrcs = Xrandr.XRRGetScreenResourcesCurrent(
        xdisplay,
        X11.XDefaultRootWindow(xdisplay),
    )
    assert isinstance(screen_resrcs.contents, X_XRRScreenResources)
    return [RandrOutputInfo(xdisplay, screen_resrcs, screen_resrcs.contents.outputs[o])
            for o in range(screen_resrcs.contents.noutput)]


def process(connected, disabled, enabled):
    xdisplay = X11.XOpenDisplay(None)
    for output_info in get_xrandr_output_infos(xdisplay):
        if ((not connected or output_info.connected)
                and (not disabled or not output_info.enabled)
                and (not enabled or output_info.enabled)):
            print(output_info.name)
    X11.XCloseDisplay(xdisplay)


def _init_argparser():
    import argparse
    argparser = argparse.ArgumentParser(
        description='Show names of outputs available to the X server.',
    )
    argparser.add_argument(
        '-c', '--connected',
        action='store_true',
        help='connected only',
    )
    argparser.add_argument(
        '-d', '--disabled',
        action='store_true',
        help='disabled only (does not imply --connected)',
    )
    argparser.add_argument(
        '-e', '--enabled',
        action='store_true',
        help='enabled only (does not imply --connected)',
    )
    return argparser


def main(argv):
    argparser = _init_argparser()
    try:
        import argcomplete
    except ImportError:
        pass
    args = argparser.parse_args(argv)
    process(**vars(args))
    return 0

if __name__ == "__main__":
    import sys
    sys.exit(main(sys.argv[1:]))