# Zope 3 imports
from zope.interface import implements
from zope.app import zapi
from zope.app.traversing.adapters import Traverser, _marker
from zope.publisher.interfaces.browser import IBrowserRequest
from zope.component import ComponentLookupError

# Five imports
from Products.Five.traversable import FiveTraversable, FakeRequest

# Product imports
from topic import Topic, AuthorsTopic


class SubpathTraverser(Traverser):

    def traverse(self, path, default=_marker, request=None):
        clear_name_stack = False
        # path looks like ['topics'], or similar...
        if path[0] in ['topics', 'authors']:
            clear_name_stack = True
            path = path + request['TraversalRequestNameStack']
        obj = super(SubpathTraverser, self).traverse(path, default, request)
        if clear_name_stack:
            request['TraversalRequestNameStack'][:] = []
        return obj


class WeblogTraversable(FiveTraversable):
    """Intercepts traversal for IWeblogs, but only for 'topics'.
    Everything else is left untouched.
    """

    def traverse(self, name, furtherPath):
        # Alias _subject to context for consistency with other adapter code
        self.context = self._subject
        # Only intercept certain names...
        if name == 'topics':
            topic_class = Topic
        elif name == 'authors':
            topic_class = AuthorsTopic
        else:
            # We ignore it and do default traversing.
            return super(WeblogTraversable, self).traverse(name, furtherPath)
        # Now the guts of it...
        # Empty furtherPath so no more traversal happens after us.
        subpath = self.popFurtherPath(furtherPath)
        # Find the REQUEST
        REQUEST = getattr(self.context, 'REQUEST', None)
        view_name = name
        if len(subpath) == 0:
            # No subpath to eat, so just lookup the 'name' view for context
            return zapi.getView(self.context, view_name, REQUEST)
        elif subpath[-1].startswith('@@'):
            # A view has explicitly been requested, so make that the
            # view_name (stripping off the leading @@ which causes view
            # lookups to fail otherwise).
            view_name = subpath[-1][2:]
            # Use the rest of the subpath as the keywords for the topic.
            topic = topic_class(subpath[:-1]).__of__(self.context)
        else:
            # No @@view given, so just lookup the default view.
            view_name = 'index.html'
            # Use all of the subpath as the keywords for the topic.
            topic = topic_class(subpath).__of__(self.context)
        # Lookup the view for the topic and return it for publishing.
        return zapi.getView(topic, view_name, REQUEST)

    def popFurtherPath(self, furtherPath):
        """Empty the furtherPath sequence into a new list.
        """
        subpath = []
        subpath.extend(furtherPath)
        while furtherPath:
            furtherPath.pop()
        return subpath