# This file is part of Xpra.
# Copyright (C) 2008, 2009 Nathaniel Smith <njs@pobox.com>
# Copyright (C) 2012-2019 Antoine Martin <antoine@xpra.org>
# Xpra is released under the terms of the GNU GPL v2, or, at your option, any
# later version. See the file COPYING for details.

"""
Functions for converting to and from X11 properties.
    prop_encode
    prop_decode
"""

import struct

from xpra.os_util import hexstr, PYTHON3
from xpra.x11.bindings.window_bindings import constants     #@UnresolvedImport
from xpra.log import Logger

log = Logger("x11", "window")

if PYTHON3:
    long = int              #@ReservedAssignment
    unicode = str           #@ReservedAssignment

USPosition      = constants["USPosition"]
PPosition       = constants["PPosition"]
PMaxSize        = constants["PMaxSize"]
PMinSize        = constants["PMinSize"]
PBaseSize       = constants["PBaseSize"]
PResizeInc      = constants["PResizeInc"]
PAspect         = constants["PAspect"]
PWinGravity     = constants["PWinGravity"]
XUrgencyHint    = constants["XUrgencyHint"]
WindowGroupHint = constants["WindowGroupHint"]
StateHint       = constants["StateHint"]
IconicState     = constants["IconicState"]
InputHint       = constants["InputHint"]


def unsupported(*_args):
    raise Exception("unsupported")

def _force_length(name, data, length, noerror_length=None):
    if len(data)==length:
        return data
    if len(data)!=noerror_length:
        log.warn("Odd-lengthed property %s: wanted %s bytes, got %s: %r"
                 % (name, length, len(data), data))
    # Zero-pad data
    data += b"\0" * length
    return data[:length]


class NetWMStrut(object):
    def __init__(self, _disp, data):
        # This eats both _NET_WM_STRUT and _NET_WM_STRUT_PARTIAL.  If we are
        # given a _NET_WM_STRUT instead of a _NET_WM_STRUT_PARTIAL, then it
        # will be only length 4 instead of 12, we just don't define the other values
        # and let the client deal with it appropriately
        if len(data)==16:
            self.left, self.right, self.top, self.bottom = struct.unpack(b"@LLLL", data)
        else:
            data = _force_length("_NET_WM_STRUT or _NET_WM_STRUT_PARTIAL", data, 4 * 12)
            (
                self.left, self.right, self.top, self.bottom,
                self.left_start_y, self.left_end_y,
                self.right_start_y, self.right_end_y,
                self.top_start_x, self.top_end_x,
                self.bottom_start_x, self.bottom_stop_x,
                ) = struct.unpack(b"@" + b"L" * 12, data)

    def todict(self):
        return self.__dict__

    def __str__(self):
        return "NetWMStrut(%s)" % self.todict()


class MotifWMHints(object):
    def __init__(self, _disp, data):
        #some applications use the wrong size (ie: blender uses 16) so pad it:
        sizeof_long = struct.calcsize(b"@L")
        pdata = _force_length("_MOTIF_WM_HINTS", data, sizeof_long*5, sizeof_long*4)
        self.flags, self.functions, self.decorations, self.input_mode, self.status = \
            struct.unpack(b"@LLLlL", pdata)
        log("MotifWMHints(%s)=%s", hexstr(data), self)

    #found in mwmh.h:
    # "flags":
    FUNCTIONS_BIT   = 0
    DECORATIONS_BIT = 1
    INPUT_MODE_BIT  = 2
    STATUS_BIT      = 3
    # "functions":
    ALL_BIT         = 0
    RESIZE_BIT      = 1
    MOVE_BIT        = 2      # like _NET_WM_ACTION_MOVE
    MINIMIZE_BIT    = 3      # like _NET_WM_ACTION_MINIMIZE
    MAXIMIZE_BIT    = 4      # like _NET_WM_ACTION_(FULLSCREEN|MAXIMIZE_(HORZ|VERT))
    CLOSE_BIT       = 5      # like _NET_WM_ACTION_CLOSE
    SHADE_BIT       = 6      # like _NET_WM_ACTION_SHADE
    STICK_BIT       = 7      # like _NET_WM_ACTION_STICK
    FULLSCREEN_BIT  = 8      # like _NET_WM_ACTION_FULLSCREEN
    ABOVE_BIT       = 9      # like _NET_WM_ACTION_ABOVE
    BELOW_BIT       = 10     # like _NET_WM_ACTION_BELOW
    MAXIMUS_BIT     = 11     # like _NET_WM_ACTION_MAXIMUS_(LEFT|RIGHT|TOP|BOTTOM)
    # "decorations":
    ALL_BIT         = 0
    BORDER_BIT      = 1
    RESIZEH_BIT     = 2
    TITLE_BIT       = 3
    MENU_BIT        = 4
    MINIMIZE_BIT    = 5
    MAXIMIZE_BIT    = 6
    #CLOSE_BIT                # non-standard close button
    #RESIZE_BIT               # non-standard resize button
    #SHADE_BIT,               # non-standard shade button
    #STICK_BIT,               # non-standard stick button
    #MAXIMUS_BIT              # non-standard maxim
    # "input":
    MODELESS        = 0
    PRIMARY_APPLICATION_MODAL = 1
    SYSTEM_MODAL    = 2
    FULL_APPLICATION_MODAL = 3
    # "status":
    TEAROFF_WINDOW  = 0

    FLAGS_STR = {
        FUNCTIONS_BIT      : "functions",
        DECORATIONS_BIT    : "decorations",
        INPUT_MODE_BIT     : "input",
        STATUS_BIT         : "status",
        }
    FUNCTIONS_STR = {
        ALL_BIT        : "all",
        RESIZE_BIT     : "resize",
        MOVE_BIT       : "move",
        MINIMIZE_BIT   : "minimize",
        MAXIMIZE_BIT   : "maximize",
        CLOSE_BIT      : "close",
        SHADE_BIT      : "shade",
        STICK_BIT      : "stick",
        FULLSCREEN_BIT : "fullscreen",
        ABOVE_BIT      : "above",
        BELOW_BIT      : "below",
        MAXIMUS_BIT    : "maximus",
        }
    DECORATIONS_STR = {
        ALL_BIT      : "all",
        BORDER_BIT   : "border",
        RESIZEH_BIT  : "resizeh",
        TITLE_BIT    : "title",
        MENU_BIT     : "menu",
        MINIMIZE_BIT : "minimize",
        MAXIMIZE_BIT : "maximize",
        }
    INPUT_STR = {
        MODELESS                   : "modeless",
        PRIMARY_APPLICATION_MODAL  : "primary-application-modal",
        SYSTEM_MODAL               : "system-modal",
        FULL_APPLICATION_MODAL     : "full-application-modal",
        }

    STATUS_STR = {
        TEAROFF_WINDOW : "tearoff",
        }

    def bits_to_strs(self, int_val, flag_bit, dict_str):
        if flag_bit and not self.flags & (2**flag_bit):
            #the bit is not set, ignore this attribute
            return ()
        return tuple(v for k,v in dict_str.items() if int_val & (2**k))
    def flags_strs(self):
        return self.bits_to_strs(self.flags,
                                 0,
                                 MotifWMHints.FLAGS_STR)
    def functions_strs(self):
        return self.bits_to_strs(self.functions,
                                 MotifWMHints.FUNCTIONS_BIT,
                                 MotifWMHints.FUNCTIONS_STR)
    def decorations_strs(self):
        return self.bits_to_strs(self.decorations,
                                 MotifWMHints.DECORATIONS_BIT,
                                 MotifWMHints.DECORATIONS_STR)
    def input_strs(self):
        if self.flags & (2**MotifWMHints.INPUT_MODE_BIT):
            return MotifWMHints.INPUT_STR.get(self.input_mode, "unknown mode: %i" % self.input_mode)
        return "modeless"
    def status_strs(self):
        return self.bits_to_strs(self.input_mode,
                                 MotifWMHints.STATUS_BIT,
                                 MotifWMHints.STATUS_STR)

    def __str__(self):
        return "MotifWMHints(%s)" % {
            "flags"         : self.flags_strs(),
            "functions"     : self.functions_strs(),
            "decorations"   : self.decorations_strs(),
            "input_mode"    : self.input_strs(),
            "status"        : self.status_strs(),
            }


def _read_image(_disp, stream):
    try:
        int_size = struct.calcsize(b"@I")
        long_size = struct.calcsize(b"@L")
        header = stream.read(long_size*2)
        if not header:
            return None
        width, height = struct.unpack(b"@LL", header)
        data = stream.read(width * height * long_size)
        expected = width * height * long_size
        if len(data) < expected:
            log.warn("Warning: corrupt _NET_WM_ICON, execpted %i bytes but got %i",
                     expected, len(data))
            return None
        if int_size!=long_size:
            #long to ints (CARD32):
            longs = struct.unpack(b"@"+b"l"*(width*height), data)
            data = struct.pack(b"@"+b"i"*(width*height), *longs)
    except Exception:
        log.warn("Weird corruption in _NET_WM_ICON", exc_info=True)
        return None
    return width, height, "BGRA", data

# This returns a cairo ImageSurface which contains the largest icon defined in
# a _NET_WM_ICON property.
def NetWMIcons(disp, data):
    icons = []
    from io import BytesIO
    stream = BytesIO(data)
    while True:
        icon = _read_image(disp, stream)
        if icon is None:
            break
        icons.append(icon)
    if not icons:
        return None
    return icons


def _to_latin1(_disp, v):
    return v.encode("latin1")

def _from_latin1(_disp, v):
    return v.decode("latin1")

def _to_utf8(_disp, v):
    return v.encode("UTF-8")

def _from_utf8(_disp, v):
    return v.decode("UTF-8")



PROP_TYPES = {
    # Python type, X type Atom, formatbits, serializer, deserializer, list
    # terminator
    "utf8": (unicode, "UTF8_STRING", 8, _to_utf8, _from_utf8, b"\0"),
    # In theory, there should be something clever about COMPOUND_TEXT here.  I
    # am not sufficiently clever to deal with COMPOUNT_TEXT.  Even knowing
    # that Xutf8TextPropertyToTextList exists.
    "latin1": (unicode, "STRING", 8, _to_latin1, _from_latin1, b"\0"),
    "state": ((int, long), "WM_STATE", 32,
            lambda _disp, c: struct.pack(b"@L", c),
            lambda _disp, d: struct.unpack(b"@L", d)[0],
            b""),
    "u32": ((int, long), "CARDINAL", 32,
            lambda _disp, c: struct.pack(b"@L", c),
            lambda _disp, d: struct.unpack(b"@L", d)[0],
            b""),
    "integer": ((int, long), "INTEGER", 32,
            lambda _disp, c: struct.pack(b"@L", c),
            lambda _disp, d: struct.unpack(b"@L", d)[0],
            b""),
    "strut": (NetWMStrut, "CARDINAL", 32,
              unsupported, NetWMStrut, None),
    "strut-partial": (NetWMStrut, "CARDINAL", 32,
                      unsupported, NetWMStrut, None),
    "motif-hints": (MotifWMHints, "_MOTIF_WM_HINTS", 32,
              unsupported, MotifWMHints, None),
    "icons": (list, "CARDINAL", 32,
              unsupported, NetWMIcons, None),
    }

PROP_SIZES = {
    "icons" : 4*1024*1024,
    }


def prop_encode(disp, etype, value):
    if isinstance(etype, (list, tuple)):
        return _prop_encode_list(disp, etype[0], value)
    return _prop_encode_scalar(disp, etype, value)

def _prop_encode_scalar(disp, etype, value):
    pytype, atom, formatbits, serialize = PROP_TYPES[etype][:4]
    assert isinstance(value, pytype), "value for atom %s is not a %s: %s" % (atom, pytype, type(value))
    return (atom, formatbits, serialize(disp, value))

def _prop_encode_list(disp, etype, value):
    (_, atom, formatbits, _, _, terminator) = PROP_TYPES[etype]
    value = tuple(value)
    serialized = tuple(_prop_encode_scalar(disp, etype, v)[2] for v in value)
    # Strings in X really are null-separated, not null-terminated (ICCCM
    # 2.7.1, see also note in 4.1.2.5)
    return (atom, formatbits, terminator.join(x for x in serialized if x is not None))


def prop_decode(disp, etype, data):
    if isinstance(etype, (list, tuple)):
        return _prop_decode_list(disp, etype[0], data)
    return _prop_decode_scalar(disp, etype, data)

def _prop_decode_scalar(disp, etype, data):
    (pytype, _, _, _, deserialize, _) = PROP_TYPES[etype]
    value = deserialize(disp, data)
    assert value is None or isinstance(value, pytype), "expected a %s but value is a %s" % (pytype, type(value))
    return value

def _prop_decode_list(disp, etype, data):
    (_, _, formatbits, _, _, terminator) = PROP_TYPES[etype]
    if terminator:
        datums = data.split(terminator)
    else:
        datums = []
        if formatbits==32:
            nbytes = struct.calcsize("@L")
        else:
            nbytes = formatbits // 8
        while data:
            datums.append(data[:nbytes])
            data = data[nbytes:]
    props = (_prop_decode_scalar(disp, etype, datum) for datum in datums)
    return [x for x in props if x is not None]
