##############################################################################
#
# Copyright (c) 2001 Zope Corporation and Contributors. All Rights Reserved.
# 
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (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
# 
##############################################################################
""" Basic portal discussion access tool.

$Id: DiscussionTool.py,v 1.2 2002/09/06 18:34:46 dreamcatcher Exp $
"""

from Globals import InitializeClass, DTMLFile
from AccessControl import ClassSecurityInfo
from OFS.SimpleItem import SimpleItem

from Products.CMFCore.utils import UniqueObject, getToolByName
from Products.CMFCore import CMFCorePermissions

from Products.CMFCore.utils import _dtmldir
from Products.CMFCore.ActionInformation import ActionInformation
from Products.CMFCore.ActionProviderBase import ActionProviderBase
from Products.CMFCore.Expression import Expression

from Forum import Forum

class DiscussionNotAllowed( Exception ):
    pass

class DiscussionTool( UniqueObject, SimpleItem, ActionProviderBase ):

    id = 'portal_discussion'
    meta_type = 'CMFForum Discussion Tool'
    _actions = [ActionInformation(id='reply'
                                , title='Reply'
                                , action=Expression(
                text='string: ${object_url}/talkback/forum_post_message')
                                , condition=Expression(
                text='python: object is not None and ' +
                'portal.portal_discussion.isDiscussionAllowedFor(object)')
                                , permissions=('Reply to item',)
                                , category='object'
                                , visible=1
                                 )]

    security = ClassSecurityInfo()

    manage_options = (ActionProviderBase.manage_options +
                     ({ 'label' : 'Overview', 'action' : 'manage_overview' }
                     , 
                     ) + SimpleItem.manage_options)

    #
    #   ZMI methods
    #
    security.declareProtected( CMFCorePermissions.ManagePortal
                             , 'manage_overview' )
    manage_overview = DTMLFile( 'explainDiscussionTool', _dtmldir )

    #
    #   'portal_discussion' interface methods
    #

    security.declarePrivate('listActions')
    def listActions(self, info=None):
        """
        Return available actions via tool.
        """
        return self._actions

    security.declarePublic( 'overrideDiscussionFor' )
    def overrideDiscussionFor(self, content, allowDiscussion):
        """
            Override discussability for a per object basis or clear and let
            the site default override.
        """
        mtool = getToolByName( self, 'portal_membership' )
        if not mtool.checkPermission( CMFCorePermissions.ModifyPortalContent
                                    , content
                                    ):
            raise "Unauthorized"

        if allowDiscussion is None or allowDiscussion == 'None':
            if hasattr(content, 'allow_discussion'):
                del content.allow_discussion
        else:
            content.allow_discussion = int(allowDiscussion)

    security.declarePublic( 'getDiscussionFor' )
    def getDiscussionFor(self, content):
        """
            Return the talkback for content, creating it if need be.
        """
        if not self.isDiscussionAllowedFor( content ):
            raise DiscussionNotAllowed
            
        talkback = getattr( content, 'talkback', None )
        if not talkback:
            talkback = self._createDiscussionFor( content )
        
        return talkback

    security.declarePublic( 'isDiscussionAllowedFor' )
    def isDiscussionAllowedFor( self, content ):
        '''
            Returns a boolean indicating whether a discussion is
            allowed for the specified content.
        '''
        if hasattr( content, 'allow_discussion' ):
            return content.allow_discussion
        typeInfo = getToolByName(self, 'portal_types').getTypeInfo( content )
        if typeInfo:
            return typeInfo.allowDiscussion()
        return 0

    #
    #   Utility methods
    #
    security.declarePrivate( '_createDiscussionFor' )
    def _createDiscussionFor( self, content ):
        """
            Create the object that holds discussion items inside
            the object being discussed, if allowed.
        """
        if not self.isDiscussionAllowedFor( content ):
            raise DiscussionNotAllowed

        # This creates the Forum
        # instead of the regular DiscussionItemContainer
        content.talkback = Forum('talkback','Discussion')
        # Set type manually, as the Forum was not created by factory.
        content.talkback._setPortalTypeName('Forum')
        return content.talkback


InitializeClass( DiscussionTool )