# Copyright (c) 2011,  2012 Free Software Foundation

#     This program is free software: you can redistribute it and/or modify
#     it under the terms of the GNU Affero General Public License as
#     published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.

#     You should have received a copy of the GNU Affero General Public License
#     along with this program.  If not, see <http://www.gnu.org/licenses/>.


# This project incorporates work covered by the following copyright and permission notice:  

#    Copyright (c) 2009, Julien Fache
#    All rights reserved.

#    Redistribution and use in source and binary forms, with or without
#    modification, are permitted provided that the following conditions
#    are met:

#    * Redistributions of source code must retain the above copyright
#      notice, this list of conditions and the following disclaimer.
#    * Redistributions in binary form must reproduce the above copyright
#      notice, this list of conditions and the following disclaimer in
#      the documentation and/or other materials provided with the
#      distribution.
#    * Neither the name of the author nor the names of other
#      contributors may be used to endorse or promote products derived
#      from this software without specific prior written permission.

#    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
#    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
#    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
#    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
#    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
#    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
#    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
#    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
#    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
#    STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
#    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
#    OF THE POSSIBILITY OF SUCH DAMAGE.

# Copyright (c) 2011,  2012 Free Software Foundation

#     This program is free software: you can redistribute it and/or modify
#     it under the terms of the GNU Affero General Public License as
#     published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.

#     You should have received a copy of the GNU Affero General Public License
#     along with this program.  If not, see <http://www.gnu.org/licenses/>.


"""Models of Objectapp"""
import warnings
from datetime import datetime

from django.db import models
from django.db.models import Q
from django.utils.html import strip_tags
from django.utils.html import linebreaks
from django.contrib.auth.models import User
from django.contrib.sites.models import Site
from django.db.models.signals import post_save
from django.utils.importlib import import_module
from django.contrib import comments
from django.contrib.comments.models import CommentFlag
from django.contrib.comments.moderation import moderator
from django.utils.translation import ugettext_lazy as _
import json
from django.contrib.markup.templatetags.markup import markdown
from django.contrib.markup.templatetags.markup import textile
from django.contrib.markup.templatetags.markup import restructuredtext


from djangoratings.fields import RatingField
from tagging.fields import TagField
from gstudio.models import Nodetype
from gstudio.models import Objecttype
from gstudio.models import Relationtype
from gstudio.models import Systemtype
from gstudio.models import Processtype
from gstudio.models import Attributetype
from gstudio.models import Attribute
from gstudio.models import Relation
from gstudio.models import Node
from gstudio.models import Edge
from gstudio.models import Author
from gstudio.models import NID
import ast
from objectapp.settings import UPLOAD_TO
from objectapp.settings import MARKUP_LANGUAGE
from objectapp.settings import GBOBJECT_TEMPLATES
from objectapp.settings import GBOBJECT_BASE_MODEL
from objectapp.settings import MARKDOWN_EXTENSIONS
from objectapp.settings import AUTO_CLOSE_COMMENTS_AFTER
from objectapp.managers import gbobjects_published
from objectapp.managers import GbobjectPublishedManager
from objectapp.managers import AuthorPublishedManager
from objectapp.managers import DRAFT, HIDDEN, PUBLISHED
from objectapp.moderator import GbobjectCommentModerator
from objectapp.url_shortener import get_url_shortener
from objectapp.signals import ping_directories_handler
from objectapp.signals import ping_external_urls_handler
from objectapp.settings import OBJECTAPP_VERSIONING

if OBJECTAPP_VERSIONING:
    import reversion
    from reversion.models import *



counter = 1
attr_counter = -1


class Author(User):
    """Proxy Model around User"""

    objects = models.Manager()
    published = AuthorPublishedManager()

    def gbobjects_published(self):
        """Return only the gbobjects published"""
        return gbobjects_published(self.gbobjects)

    #@models.permalink
    def get_absolute_url(self):
        """Return author's URL"""
        return "/authors/%s/" %(self.username)
        #return ('objectapp_author_detail', (self.username,))

    class Meta:
        """Author's Meta"""
        proxy = True



class Gbobject(Node):
    """
    Member nodes of object types. This is actually to be named the
    Object class, since 'Object' is a reserved name in Python, we
    prefix this with 'Gb', to suggest that it is an object of the gnowledge
    base.  System and Process classes also inherit this class.
    """


    STATUS_CHOICES = ((DRAFT, _('draft')),
                      (HIDDEN, _('hidden')),
                      (PUBLISHED, _('published')))

    content = models.TextField(_('content'), null=True, blank=True)
    # content_org = models.TextField(_('content'), null=True, blank=True)
    image = models.ImageField(_('image'), upload_to=UPLOAD_TO,
                              blank=True, help_text=_('used for illustration'))

    excerpt = models.TextField(_('excerpt'), blank=True,
                                help_text=_('optional element'))

    prior_nodes = models.ManyToManyField('self', symmetrical=False,null=True, blank=True,
                               verbose_name=_('depends on'),
                               related_name='gbobject_posterior_nodes')

    posterior_nodes = models.ManyToManyField('self', symmetrical=False,null=True, blank=True,
                               verbose_name=_('required for'),
                               related_name='gbobject_prior_nodes')


    tags = TagField(_('tags'))
    objecttypes = models.ManyToManyField(Nodetype, verbose_name=_('member of'),
                                        related_name='member_objects',
                                        blank=True, null=True)
  

    authors = models.ManyToManyField(User, verbose_name=_('authors'),
                                     related_name='gbobjects',
                                     blank=True, null=False)
    

    featured = models.BooleanField(_('featured'), default=False)
    comment_enabled = models.BooleanField(_('comment enabled'), default=True)
    pingback_enabled = models.BooleanField(_('linkback enabled'), default=True)

        
    login_required = models.BooleanField(
        _('login required'), default=False,
        help_text=_('only authenticated users can view the gbobject'))
    password = models.CharField(
        _('password'), max_length=50, blank=True,
        help_text=_('protect the gbobject with a password'))

    template = models.CharField(
        _('template'), max_length=250,
        default='objectapp/gbobject_detail.html',
        choices=[('objectapp/gbobject_detail.html', _('Default template'))] + \
        GBOBJECT_TEMPLATES,
        help_text=_('template used to display the gbobject'))
    rurl=models.URLField(_('rurl'),verify_exists=True,null=True, blank=True)
    objects = models.Manager()
    published = GbobjectPublishedManager()

        
    @property
    def getattributetypes(self):
        """ 
        Returns the attributetypes of self as well as its parent's attributetype.
        """
        try:
            originalnt = []
            pt = []
            attributetype = []
            returndict = {}
            obj = self
            originalnt = obj.objecttypes.all()

            for i in range(len(originalnt)):
                obj = originalnt[i].ref
                pt.append(obj)
                while  obj.parent:
                    pt.append((obj.parent).ref)
                    obj = obj.parent
            
            attributetype.append(obj.subjecttype_of.all())
            for each in pt:
                attributetype.append(each.subjecttype_of.all())

            attributetype = [num for elem in attributetype for num in elem]
            
            for i in attributetype:
                returndict.update({str(i.title):i.id})

            return returndict.keys()
        
        except:
            return None

  

    @property
    def getrelationtypes(self):
        originalnt= []
        originalpt = []
        pt =[] #contains parenttype
        reltype =[] #contains relationtype
        titledict = {} #contains relationtype's title
        inverselist = [] #contains relationtype's inverse
        finaldict = {} #contains either title of relationtype or inverse of relationtype
        listval=[] #contains keys of titledict to check whether parenttype id is equals to listval's left or right subjecttypeid
        
        gb=self.ref
        originalnt = gb.objecttypes.all()
        for i in originalnt:
            pt.append(i.ref)
        
        for i in range(len(originalnt)):
            obj = originalnt[i].ref
            while  obj.parent:
                pt.append((obj.parent).ref)
                obj = obj.parent
        pt.append(gb)
        for i in range(len(pt)):
            if Relationtype.objects.filter(left_subjecttype = pt[i].id):
                reltype.append(Relationtype.objects.filter(left_subjecttype = pt[i].id))    
            if Relationtype.objects.filter(right_subjecttype = pt[i].id):
                 reltype.append(Relationtype.objects.filter(right_subjecttype = pt[i].id)) 
                
        reltype = [num for elem in reltype for num in elem]
        
        for i in reltype:
            titledict.update({i:i.id})

            
        for i in range(len(titledict)):
            listval.append(Relationtype.objects.get(title = titledict.keys()[i]))
            inverselist.append(titledict.keys()[i].inverse)            
   
        for j in range(len(pt)):
            for i in range(len(listval)):
                if pt[j].id == listval[i].left_subjecttype_id and (str(listval[i].left_applicable_nodetypes) == 'OT' or str(listval[i].left_applicable_nodetypes) == 'OB'):
                    finaldict.update({titledict.keys()[i]:titledict.values()[i]})
                if pt[j].id == listval[i].right_subjecttype_id and (str(listval[i].right_applicable_nodetypes)=='OT' or str(listval[i].right_applicable_nodetypes) == 'OB'):
                    finaldict.update({inverselist[i]:titledict.values()[i]})



        return finaldict.keys()
 
    def get_relations(self):
        relation_set = {}
        # ALGO to find the relations and their left-subjecttypes and right_subjecttypes
        # 1. Get the relations containing a reference to the object. Retrieve where it occurs (left or right)
        # 2. Find out which RT they come from.
        # 3. For each RT, create a dict key and a value as a dict. And add the relation as a new key-value pair (rid:subject).
        # 4. If self is in right value, then add inverse relation as RT and add the relation as a new key-value pair (rid:subject).

        left_relset = Relation.objects.filter(left_subject=self.id) 
        right_relset = Relation.objects.filter(right_subject=self.id) 
        
        #return left_relset + right_relset

        # RT dictionary to store a single relation
        rel_dict ={}
        rel_dict['left-subjecttypes'] = {}
        rel_dict['right_subjecttypes'] ={}

               
        for relation in left_relset:
            # check if relation already exists
            if relation.relationtype.title not in rel_dict['left-subjecttypes'].keys():
                # create a new list field and add to it
                rel_dict['left-subjecttypes'][str(relation.relationtype.title)] = []
            # add 
            rel_dict['left-subjecttypes'][str(relation.relationtype.title)].append(relation) 

        for relation in right_relset:
            # check if relation exists
            if relation.relationtype.inverse not in rel_dict['right_subjecttypes'].keys():
                # create a new list key field and add to it
                rel_dict['right_subjecttypes'][str(relation.relationtype.inverse)] = []
                # add to the existing key
            rel_dict['right_subjecttypes'][str(relation.relationtype.inverse)].append(relation)

        relation_set.update(rel_dict['left-subjecttypes'])
        relation_set.update(rel_dict['right_subjecttypes'])
        
        return relation_set
       


    def get_attributes(self):
        attributes_dict =  {}
        all_attributes=self.subject_of.all()
        for attributes in all_attributes:
                val=[]
        	atr_key=attributes.attributetype.title
                val.append(attributes.svalue)
		
                if attributes_dict:
                     fl=0
                     itms=attributes_dict
                     
                     for key,value in itms.items():
                     	  if atr_key in key:
                                 fl=1
                                 if type(value) <> list:
                                      t=[]
                                      t.append(value)
                                      val.extend(t)
                                      
                                 else:
                                      
                                      val.extend(value)
                                      
                attributes_dict[atr_key]=val
                
        return attributes_dict
            
    
    
    def get_possible_rels(self):
        """
        Gets the relations possible for this metatype
        1. Recursively create a set of all the ancestors i.e. parent/subtypes of the MT. 
        2. Get all the R's linked to each ancestor 
        """
        #Step 1. 
        ancestor_list = []
        this_parent = self.parent
        
        # append
        while this_parent:
            ancestor_list.append(this_parent)
            this_parent = this_parent.parent
            
        #Step 2.
        rels = {}
        rt_set = Relation.objects.all()
        right_subset = []
        left_subset = []
        
        for each in ancestor_list:
            # retrieve all the RT's from each ancestor 
            right_subset.extend(rt_set.filter(subject1=each.id))
            left_subset.extend(rt_set.filter(subject2=each.id))
         
        rels['possible_leftroles'] = left_subset
        rels['possible_rightroles'] = right_subset
        
        return rels


    def get_possible_attributes(self):
        """
        Gets the relations possible for this metatype
        1. Recursively create a set of all the ancestors i.e. parent/subtypes of the MT. 
        2. Get all the RT's linked to each ancestor 
        """
        #Step 1. 
        ancestor_list = []
        this_parent = self.parent
        
        # recursive thru parent field and append
        while this_parent:
            ancestor_list.append(this_parent)
            this_parent = this_parent.parent
            
        #Step 2.
        attrs = [] 
                
        for each in ancestor_list:
            # retrieve all the AT's from each ancestor 
            attrs.extend(Attribute.objects.filter(subject=each.id))
                     
        return attrs




    @property
    def get_nbh(self):
        """ 
        Returns the neighbourhood of the object
        """
        fields = ['title','altname','pluralform']
        nbh = {}
        nbh['title'] = self.title        
        nbh['altnames'] = self.altnames                
        nbh['plural'] = self.plural
        nbh['content'] = self.content
        #return  all OTs the object is linked to
        nbh['member_of'] = self.objecttypes.all()
        
        # get all the relations of the object    
        nbh.update(self.get_relations())
        nbh.update(self.get_attributes())
        # encapsulate the dictionary with its node name as key
        return nbh

    
    def get_graph_json(self):
        
        
        
	g_json = {}
	g_json["node_metadata"]= [] 
	g_json["relations"]=[]
	

	global counter 
	global attr_counter
	nbh = self.get_nbh
	predicate_id = {}
        
        for key in nbh.keys():
            val = str(counter) + "b"
            predicate_id[key] = val
            counter = counter + 1
        #print predicate_id

       

        this_node = {"_id":str(self.id),"title":self.title,"screen_name":self.title, "url":self.get_absolute_url(),"refType":self.reftype}
        g_json["node_metadata"].append(this_node)      
	

	for key in predicate_id.keys():
		if nbh[key]:
                    try:
				
                        g_json["node_metadata"].append({"_id":str(predicate_id[key]),"screen_name":key})
                        
                        g_json["relations"].append({"from":self.id ,"type":str(key),"value":1,"to":predicate_id[key] })

                        if not isinstance(nbh[key],basestring) and len(nbh[key])<=2:
                            for item in nbh[key]:
                                if isinstance(item,unicode):
                                    g_json["node_metadata"].append({"_id":(str(attr_counter)+"b"),"screen_name":str(item)})
                                    g_json["relations"].append({"from":predicate_id[key] ,"type":str(key) ,"value":1,"to":(str(attr_counter)+"b") })
                                    attr_counter-=1
                                    
                                elif item.reftype!="Relation":
                                    # create nodes
                                    g_json["node_metadata"].append({"_id":str(item.id),"screen_name":item.title,"title":self.title, "url":item.get_absolute_url(),"refType":item.reftype})
                                    g_json["relations"].append({"from":predicate_id[key] ,"type":str(key), "value":1,"to":item.id  })
                                    
                                else:
                                    
                                    if item.left_subject.id==self.id:
                                        item1=item.right_subject
                                        flag=1
                                        
                                    elif item.right_subject.id==self.id:
                                        item1=item.left_subject
                                        flag=0						
                                        
                                    g_json["node_metadata"].append({"_id":str(item1.id),"screen_name":item1.title,"title":self.title, "url":item1.get_absolute_url(),"refType":item.reftype,"inverse":item.relationtype.inverse,"flag":flag})
                                        
                                        
                                    g_json["relations"].append({"from":predicate_id[key] ,"type":str(key), "value":1,"to":item1.id  })
                        else:
                            if not isinstance(nbh[key],basestring):
                                g_json["node_metadata"].append({"_id":(str(attr_counter))+"a","screen_name":str(len(nbh[key]))+" nodes...","title":str(key),"url":"/nodetypes/graphs/graph_label/"+str(self.id)+"/"+str(key)})
					#g_json["relations"].append({"from":predicate_id[key] ,"type":str(key) ,"value":1,"to":(str(attr_counter))})
                            else:
                                g_json["node_metadata"].append({"_id":(str(attr_counter)+"a"),"screen_name":nbh[key]})
    
                            g_json["relations"].append({"from":predicate_id[key] ,"type":str(key) ,"value":1,"to":(str(attr_counter)+"a")})

                            attr_counter-=1

                    except:
                            pass
                            
        #print g_json
        return json.dumps(g_json)   
    def get_label(self,key):
        nbh=self.get_nbh
        list_of_nodes=[]
        for item in nbh[key]:
            node = NID.objects.get(id=item.id)
            node = node.ref
            list_of_nodes.append(node)
            return list_of_nodes



    def get_Version_graph_json(self,ssid):
        
            
        # # predicate_id={"plural":"a1","altnames":"a2","contains_members":"a3","contains_subtypes":"a4","prior_nodes":"a5", "posterior_nodes":"a6"}
        # slist=self.get_ssid
        ver_dict=self.version_info(ssid)
        ver_dict1=self.version_info(ssid)
        #ver_dict=str(ver['nbhood'])
        ver_dict=ast.literal_eval(ver_dict['nbhood'])
        g_json = {}
        g_json["node_metadata"]= [] 
        g_json["relations"]=[]
        predicate_id = {}
        counter=1
        attr_counter=-1
        for key in ver_dict.keys():
            val = "a" + str(counter)
            predicate_id[key] = val
            counter = counter + 1
         #print predicate_id
            
         

            this_node = {"_id":str(self.id),"title":self.title,"screen_name":self.title, "url":self.get_absolute_url(),"refType":self.reftype}
            g_json["node_metadata"].append(this_node) 
   

            for key in predicate_id.keys():
        	if (ver_dict[key] and (ver_dict[key])!=0 and not(isinstance(ver_dict[key],int ) )) :
                    try: 
                        
                        g_json["node_metadata"].append({"_id":str(predicate_id[key]),"screen_name":key})
                        g_json["relations"].append({"from":self.id , "to":predicate_id[key],"value":1, "type":str(key) })
                        
                        if not isinstance(ver_dict[key],basestring):
                            for item in ver_dict[key]:
                                # user 
                                g_json["node_metadata"].append({"_id":(str(attr_counter)+"aa"),"screen_name":item })			
						#create links
                                g_json["relations"].append({"from":predicate_id[key] ,"type":str(key), "value":1,"to":(str(attr_counter)+"aa")  })
                                attr_counter-=1
                            else:
                                
                                g_json["node_metadata"].append({"_id":(str(attr_counter)+"a"),"screen_name":ver_dict[key]})
                                g_json["relations"].append({"from":predicate_id[key] , "to":(str(attr_counter)+"a") ,"value":1, "type":str(key) })
                                attr_counter-=1
                                
                                
                    except:
                        pass
# print g_json
                    
                    
                    
                    return json.dumps(g_json)

    @property
    def get_rendered_relations(self):
        """
        Returns all the relations of the nodetype
        """
        relations={}
        reltype={}
        left_relations=Relation.objects.filter(left_subject=self.id)
        if left_relations:
           for each in left_relations:
           	relation=each.relationtype.title
           	predicate=each.right_subject
           	predicate_values=[]
                if reltype:
              	   fl=0
              	   for key,value in reltype.items():
                       if type(value) <> list:
                          t=[]
                          t.append(value)
                          predicate_values=t
                       else:
                          predicate_values=value
                       if each.relationtype.title==key:
                          fl=1
                          predicate_values.append(predicate)
                          reltype[key]=predicate_values
                   if fl==0:
                       predicate_values=predicate
                       reltype[relation]=predicate_values
                else:
                    predicate_values.append(predicate)
                    reltype[relation]=predicate_values
                relations['lrelations']=reltype
        
        right_relations=Relation.objects.filter(right_subject=self.id)
        reltype={}
        if right_relations:
           for each in right_relations:
           	relation=each.relationtype.inverse
           	predicate=each.left_subject
                predicate_values=[]
                if reltype:
                   fl=0
              	   for key,value in reltype.items():
                       if type(value) <> list:
                          t=[]
                          t.append(value)
                          prdicate_values=t
                       else:
                          predicate_values=value
                       if each.relationtype.inverse==key:
                          fl=1
                          predicate_values.append(predicate)
                          reltype[key]=predicate_values
                          
                   if fl==0:
                       predicate_values=predicate
                       reltype[relation]=predicate_values
                          
                else:
                   predicate_values.append(predicate)
                   reltype[relation]=predicate_values
                relations['rrelations']=reltype
        return relations

    @property
    def get_rendered_nbh(self):
        """ 
        Returns the neighbourhood of the object
        """
        fields = ['title','altname','pluralform']
        history=[]
        version_list=self.get_ssid
        version_list=self.get_ssid
        if version_list:
		length=len(version_list)
        	history_ssid=version_list[length-1]
        	history_dict=self.version_info(history_ssid)
        	history_nbh_dict=ast.literal_eval(history_dict['nbhood'])
        	#ssid_current.append(history_ssid)
        	history=history_nbh_dict['history']
        	history.append(history_ssid)
        else:
                history.append(0)
        nbh = {}
        nbh['title'] = self.title        
        nbh['altnames'] = self.altnames                
        nbh['plural']=self.plural
        nbh['content'] = self.content
        #return  all OTs the object is linked to
        member_of_dict = {}
        for each in self.objecttypes.all():
            member_of_dict[each.title]= each.get_absolute_url()
        nbh['member_of']=member_of_dict

        pnode_dict = {}
        for each in self.prior_nodes.all():
            pnode_dict[each.title]= each.get_absolute_url()
        nbh['priornodes']=pnode_dict

        pnode_dict = {}
        for each in self.posterior_nodes.all():
            pnode_dict[each.title]= each.get_absolute_url()
        nbh['posteriornodes']=pnode_dict

        #get Relations
        relns={}
        rellft={}
        relrgt={}
        if self.get_rendered_relations:
            NTrelns=self.get_rendered_relations
            for key,value in NTrelns.items():
                if key=="rrelations":
                    relrgt={}
                    for rgtkey,rgtvalue in value.items():
                        relnvalue={}
                        if isinstance(rgtvalue,list):
                            for items in rgtvalue:
                                relnvalue[items.title]=items.get_absolute_url()
                        else:
                            relnvalue[rgtvalue.title]=rgtvalue.get_absolute_url()
                        
                        relrgt[rgtkey]=relnvalue
                    
                else:
                    rellft={}
                    relns['left']=rellft
                    for lftkey,lftvalue in value.items():
                        relnvalue={}
                        if isinstance(lftvalue,list):
                             for items in lftvalue:
                                 relnvalue[items.title]=items.get_absolute_url()
                        else:
                             relnvalue[lftvalue.title]=lftvalue.get_absolute_url()
                        
                        rellft[lftkey]=relnvalue
                    
        nbh['relations']=relrgt
        nbh['relations'].update(rellft)
   

        #get Attributes
        attributes =self.get_attributes()
        nbh['attributes']=attributes
        nbh['history']=history     	
        return nbh



    @property
    def html_content(self):
        """Return the content correctly formatted"""
        if MARKUP_LANGUAGE == 'markdown':
            return markdown(self.content, MARKDOWN_EXTENSIONS)
        elif MARKUP_LANGUAGE == 'textile':
            return textile(self.content)
        elif MARKUP_LANGUAGE == 'restructuredtext':
            return restructuredtext(self.content)
        elif not '</p>' in self.content:
            return linebreaks(self.content)
        return self.content


    @property
    def previous_gbobject(self):
        """Return the previous gbobject"""
        gbobjects = Gbobject.published.filter(
            creation_date__lt=self.creation_date)[:1]
        if gbobjects:
            return gbobjects[0]

    @property
    def next_gbobject(self):
        """Return the next gbobject"""
        gbobjects = Gbobject.published.filter(
            creation_date__gt=self.creation_date).order_by('creation_date')[:1]
        if gbobjects:
            return gbobjects[0]

    @property
    def word_count(self):
        """Count the words of an gbobject"""
        return len(strip_tags(self.html_content).split())

    @property
    def is_actual(self):
        """Check if an gbobject is within publication period"""
        now = datetime.now()
        return now >= self.start_publication and now < self.end_publication

    @property
    def is_visible(self):
        """Check if an gbobject is visible on site"""
        return self.is_actual and self.status == PUBLISHED

    @property
    def related_published(self):
        """Return only related gbobjects published"""
        return gbobjects_published(self.related)

    @property
    def discussions(self):
        """Return published discussions"""
        return comments.get_model().objects.for_model(
            self).filter(is_public=True)

    @property
    def comments(self):
        """Return published comments"""
        return self.discussions.filter(Q(flags=None) | Q(
            flags__flag=CommentFlag.MODERATOR_APPROVAL))

    @property
    def pingbacks(self):
        """Return published pingbacks"""
        return self.discussions.filter(flags__flag='pingback')

    @property
    def trackbacks(self):
        """Return published trackbacks"""
        return self.discussions.filter(flags__flag='trackback')

    @property
    def comments_are_open(self):
        """Check if comments are open"""
        if AUTO_CLOSE_COMMENTS_AFTER and self.comment_enabled:
            return (datetime.now() - self.start_publication).days < \
                   AUTO_CLOSE_COMMENTS_AFTER
        return self.comment_enabled

    @property
    def short_url(self):
        """Return the gbobject's short url"""
        return get_url_shortener()(self)

    def __unicode__(self):
        return self.title

    @property
    def memberof_sentence(self):
        """Return the objecttype of which the gbobject is a member of"""
        
        if self.objecttypes.count:
            for each in self.objecttypes.all():
                return '%s is a member of objecttype %s' % (self.title, each)
        return u'%s is not a fully defined name, consider making it a member of a suitable objecttype' % (self.title)

    @property
    def ref(self):
        return eval(self.nodemodel).objects.get(id=self.id)
    @models.permalink
    def get_absolute_url(self):
        """Return gbobject's URL"""
        return ('objectapp_gbobject_detail', (), {
            'year': self.creation_date.strftime('%Y'),
            'month': self.creation_date.strftime('%m'),
            'day': self.creation_date.strftime('%d'),
            'slug': self.slug})

    # @reversion.create_revision()
    def save(self, *args, **kwargs):
        self.nodemodel = self.__class__.__name__
	super(Gbobject, self).save(*args, **kwargs) # Call the "real" save() method.
	self.nbhood=self.get_rendered_nbh
        if OBJECTAPP_VERSIONING:
            with reversion.create_revision():
                super(Gbobject, self).save(*args, **kwargs) # Call the "real" save() method.        
        
    def save_revert_or_merge(self, *args, **kwargs):
        if OBJECTAPP_VERSIONING:
            with reversion.create_revision():
                super(Gbobject, self).save(*args, **kwargs) # Call the "real" save() method.        

    class Meta:
        """Gbobject's Meta"""
        ordering = ['-creation_date']
        verbose_name = _('object')
        verbose_name_plural = _('objects')
        permissions = (('can_view_all', 'Can view all'),
                       ('can_change_author', 'Can change author'), )



class Process(Gbobject):    

    """
    A store processes, events or changes described as changes in attributes and relations
    """
    processtypes = models.ManyToManyField(Processtype, verbose_name=_('member of process type'),
                                          related_name='member_processes',
                                          blank=True, null=True)
    priorstate_attribute_set = models.ManyToManyField(Attribute, null=True, blank=True,
                                                      verbose_name=_('in prior state attribute set of'),
                                                      related_name='in_prior_state_attrset_of')
    priorstate_relation_set = models.ManyToManyField(Relation, null=True, blank=True,
                                                     verbose_name=_('priorsate of relation set'),
                                                     related_name='in_prior_state_relset_of')

    poststate_attribute_set = models.ManyToManyField(Attribute, null=True, blank=True,
                                                     verbose_name=_('poststate of attribute set'),
                                                     related_name='in_post_state_attrset_of')

    poststate_relation_set = models.ManyToManyField(Relation, null=True, blank=True,
                               verbose_name=_('in poststate of relation set'),
                               related_name='in_post_state_relset_of')




    def __unicode__(self):
        return self.title

    # @reversion.create_revision()
    def save(self, *args, **kwargs):
        self.nodemodel = self.__class__.__name__
	super(Process, self).save(*args, **kwargs) # Call the "real" save() method.
	self.nbhood=self.get_rendered_nbh
        if OBJECTAPP_VERSIONING:
            with reversion.create_revision():
		super(Process, self).save(*args, **kwargs) # Call the "real" save() method.
    
    def save_revert_or_merge(self, *args, **kwargs):
	self.nodemodel = self.__class__.__name__
	if OBJECTAPP_VERSIONING:
            with reversion.create_revision():
		super(Process, self).save(*args, **kwargs) # Call the "real" save() method.
    
    class Meta:
        verbose_name = _('process')
        verbose_name_plural = _('processes')
        permissions = (('can_view_all', 'Can view all'),
                       ('can_change_author', 'Can change author'), )


class System(Gbobject):    

    """
    instance of a Systemtype
    """

    systemtypes = models.ManyToManyField(Systemtype, verbose_name=_('member of systemtype'),
                                        related_name='member_systems',
                                         blank=True, null=True)

    gbobject_set = models.ManyToManyField(Gbobject, related_name="in_gbobject_set_of", 
                                       verbose_name='objects in the system',    
                                       blank=True, null=False) 

    relation_set = models.ManyToManyField(Relation, related_name="in_relation_set_of", 
                                         verbose_name='relations in the system',    
                                         blank=True, null=False) 

    attribute_set = models.ManyToManyField(Attribute, related_name="in_attribute_set_of", 
                                          verbose_name='attributes in the system',
                                          blank=True, null=False)

    process_set = models.ManyToManyField(Process, related_name="in_process_set_of", 
                                        verbose_name='processes in the system',    
                                        blank=True, null=False) 

    system_set = models.ManyToManyField('self', related_name="in_system_set_of", 
                                       verbose_name='nested systems',
                                       blank=True, null=False)
    # @reversion.create_revision()
    def save(self, *args, **kwargs):
        self.nodemodel = self.__class__.__name__
	super(System, self).save(*args, **kwargs) # Call the "real" save() method.
	self.nbhood=self.get_rendered_nbh
        if OBJECTAPP_VERSIONING:
            with reversion.create_revision():
                super(System, self).save(*args, **kwargs) # Call the "real" save() method.
    
    def save_revert_or_merge(self, *args, **kwargs):
	self.nodemodel = self.__class__.__name__
	if OBJECTAPP_VERSIONING:
            with reversion.create_revision():
		super(System, self).save(*args, **kwargs) # Call the "real" save() method.

        


    def __unicode__(self):
        return self.title


if OBJECTAPP_VERSIONING == True:   
    if not reversion.is_registered(Process):
        reversion.register(Process, follow=["gbobject_ptr","priorstate_attribute_set", "priorstate_relation_set", "poststate_attribute_set", "poststate_relation_set", "prior_nodes", "posterior_nodes"])

    if not reversion.is_registered(System): 
        reversion.register(System, follow=["gbobject_ptr","systemtypes", "gbobject_set", "relation_set", "attribute_set", "process_set", "system_set", "prior_nodes", "posterior_nodes"])

    if not reversion.is_registered(Gbobject):
        reversion.register(Gbobject, follow=["node_ptr","objecttypes", "prior_nodes", "posterior_nodes"])


moderator.register(Gbobject, GbobjectCommentModerator)

post_save.connect(ping_directories_handler, sender=Gbobject,
                  dispatch_uid='objectapp.gbobject.post_save.ping_directories')
post_save.connect(ping_external_urls_handler, sender=Gbobject,
                  dispatch_uid='objectapp.gbobject.post_save.ping_external_urls')