from zope.publisher.http import HTTPRequest
from zope.publisher.browser import BrowserRequest
from zope.publisher.xmlrpc import XMLRPCRequest

from zope.app.publication.httpfactory import HTTPPublicationRequestFactory
from zope.app.publication.http import HTTPPublication
from zope.app.publication.browser import BrowserPublication
from zope.app.publication.xmlrpc import XMLRPCPublication

_browser_methods = 'GET', 'POST', 'HEAD'

# TODO make this configurable through a ZConfig file
_dav_user_agents = ['cadaver/0.22.2 neon/0.24.7',
                    'cadaver/0.20.5 neon/0.23.9',
                    'neon/0.23.9 cadaver/0.20.5']

class DAVUserAgentFactory(HTTPPublicationRequestFactory):

    def __init__(self, db):
        super(DAVUserAgentFactory, self).__init__(db)
        self._request_cls = HTTPRequest
        self._publication_cls = HTTPPublication

    def makeRequest(self, request_cls, publication_cls, *args):
        # remember the kind of request and publication class for tests
        self._request_cls = request_cls
        self._publication_cls = publication_cls
        return request_cls(*args)

    def __call__(self, input_stream, output_steam, env):
        """See `zope.app.publication.interfaces.IPublicationRequestFactory`"""
        method = env.get('REQUEST_METHOD', 'GET').upper()

        # only make a distinction if we're dealing with browser
        # methods at all
        if method not in _browser_methods:
            request = self.makeRequest(HTTPRequest, HTTPPublication,
                                       input_stream, output_steam, env)
            request.setPublication(self._http)
            return request

        content_type = env.get('CONTENT_TYPE', '')
        is_xml = content_type.startswith('text/xml')
 
        if (method == 'POST' and is_xml):
            request= self.makeRequest(XMLRPCRequest, XMLRPCPublication,
                                      input_stream, output_steam, env)
            request.setPublication(self._xmlrpc)
            return request

        # check if we have a distinguished DAV client
        user_agent = env.get('HTTP_USER_AGENT', '')
        # TODO saner detection logic
        if user_agent in _dav_user_agents:
            request = self.makeRequest(HTTPRequest, HTTPPublication,
                                       input_stream, output_steam, env)
            request.setPublication(self._http)
            return request

        # fallback to a regular browser request
        request = self.makeRequest(BrowserRequest, BrowserPublication,
                                   input_stream, output_steam, env)
        request.setPublication(self._brower) # typo in superclass
        return request