##############################################################################
# Copyright (c) 2003 Zope Corporation and Contributors.
# All Rights Reserved.
# 
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
##############################################################################
"""HTTP method `OPTIONS`

$Id: options.py 29143 2005-02-14 22:43:16Z srichter $
"""
__docformat__ = 'restructuredtext'

_allowed_methods = ['PUT', 'DELETE', 'CONNECT', \
           'OPTIONS', 'PATCH', 'PROPFIND', 'PROPPATCH', 'MKCOL', \
           'COPY', 'MOVE', 'LOCK', 'UNLOCK', 'TRACE']
           # 'GET', 'HEAD', 'POST' are always available. See OPTIONS() method.

from zope.app import zapi

class OPTIONS(object):
    """`OPTIONS` handler for all objects
    """

    def __init__(self, context, request):
        self.context = context
        self.request = request

    def OPTIONS(self):
        allowed = ['GET', 'HEAD', 'POST']
        # TODO: This could be cleaned up by providing special target
        # interfaces for HTTP methods. This way we can even list verbs that
        # are not in the lists above.
        for m in _allowed_methods:
            view = zapi.queryMultiAdapter((self.context, self.request), name=m)
            if view is not None:
                allowed.append(m)

        self.request.response.setHeader('Allow', ', '.join(allowed))
        # TODO: Most of the time, this is a lie. We not fully support
        # DAV 2 on all objects, so probably an interface check is needed.
        self.request.response.setHeader('DAV', '1,2', literal=True)
        # UGLY! Some clients rely on this. eg: MacOS X
        self.request.response.setHeader('MS-Author-Via', 'DAV', literal=True)
        self.request.response.setStatus(200)
        return ''