## $Id$
##
## Copyright (C) 2011 Uli Fouquet & Henrik Bettermann
## 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.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
##
import os
from zope.component.zcml import handler
from zope.configuration.exceptions import ConfigurationError
from kofacustom.nigeria.paypal.interfaces import IPaypalConfig
from kofacustom.nigeria.paypal.config import parse_paypal_config


def paypal_handler(path):
    """ZCML handler that registers paypal configuration.

    We expect paypal credentials written down in a config file. The
    path to this config file can be set with the ZCML `paypalconf`
    directive, which is handled here and looks like this::

      <kofacustomng:paypalconf path='/some/path/to/paypal.conf' />

    This handler requires the given path to exist and to be a file.

    If the file exists and is readable, a dict with ``path`` and other
    values read from the configuration file is registered as a global
    unnamed utility for the `IPaypalConfig` interface.
    """
    if not os.path.exists(path):
        raise ConfigurationError("No such file: %s" % path)
    if not os.path.isfile(path):
        raise ConfigurationError("Not a regular file: %s" % path)
    config_dict = parse_paypal_config(path)
    config_dict["path"] = path
    return handler(
        'registerUtility', config_dict, IPaypalConfig, '')


def paypal_conf(context, path):
    """Handler for ZCML paypalconf directive.

    This handler registers the `paypal_handler` above to perform the
    real configuration action.
    """
    context.action(
        discriminator=('utility', IPaypalConfig, ''),
        callable=paypal_handler,
        args=(path, )
        )