# This file is part of MyPaint.
# Copyright (C) 2018 by the MyPaint Development Team.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

"""Function equivalents of (GLib) gettext's C macros.

Recommended usage:

  >>> from lib.gettext import C_
  >>> from lib.gettext import ngettext

Also supported, but mildly deprecated (consider C_ instead!):

  >>> from lib.gettext import gettext as _

Lots of older code uses ``from gettext import gettext as _``.
Don't do that in new code: pull in this module as ``lib.gettext``.
Importing this module should still work from within lib/ if code
still uses a relative import, however.

"""

from __future__ import absolute_import, division, print_function

from warnings import warn
from gi.repository import GLib

# Set the default encoding like PyGTK
from lib.pycompat import PY3
import sys
if not PY3:
    reload(sys)  # noqa: F821
    sys.setdefaultencoding("utf-8")

# Older code in lib imports these as "from gettext import gettext as _".
# Pull them in for backwards compat.
# Might change these to _Glib.dgettext/ngettext instead.

from gettext import gettext  # noqa: F401 E402
from gettext import ngettext  # noqa: F401 E402


# Newer code should use C_() even for simple cases, and provide contexts
# for translators.

def C_(context, msgid):  # noqa: N802
    """Mark a string for translation, with supplied context.

    :param str context: Disambiguating context.
    :param str msgid: String to translate.
    :returns: the translated Unicode string
    :rtype: str

    Convenience wrapper around g_dpgettext2. It's a function not a
    macro, but use it as if it was a C macro only: in other words, only
    use string literals so that the strings marked for translation can
    be extracted.

    Writing the context as a regular string literal and the string
    marked for translation as an explicit unicode lteral makes the fake
    macro easier to read in the code.

    """
    g_dpgettext2 = GLib.dpgettext2
    try:
        result = g_dpgettext2(None, context, msgid)
    except TypeError as e:
        # Expect "Argument 0 does not allow None as a value" sometimes.
        # This is a known problem with Ubuntu Server 12.04 when testing
        # lib - that version of g_dpgettext2() does not appear to allow
        # NULL for its first arg.
        wtmpl = "C_(): g_dpgettext2() raised %r. Try a newer GLib?"
        warn(
            wtmpl % (e,),
            RuntimeWarning,
            stacklevel = 1,
        )
        return msgid
    else:
        if isinstance(result, bytes):
            # GLib.dbgettext in PY2 does this, but PY3 doesn't. Weird.
            # Let's assume we can trust the Unicode string we get handed
            # in Python 3, and hope that this won't create a pile of
            # mojibake on screen.
            result = result.decode("utf-8")
        return result
