## Copyright 2009-2013 Luc Saffre
## This file is part of the Lino project.
## Lino is free software; you can redistribute it and/or modify 
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or
## (at your option) any later version.
## Lino 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 General Public License for more details.
## You should have received a copy of the GNU General Public License
## along with Lino; if not, see <http://www.gnu.org/licenses/>.

"""
This defines the :class:`Table` class (``dd.Table``).
"""

import logging
logger = logging.getLogger(__name__)

import copy
import cgi
import os
import sys
import traceback
import codecs
import yaml
import datetime
#import logging ; logger = logging.getLogger('lino.reports')
#~ import cPickle as pickle
#~ import pprint

from appy import Object

from django.conf import settings
#~ from django.utils.translation import ugettext as _
from django.utils.translation import ugettext_lazy as _
from django.utils.text import capfirst
from django.utils.encoding import force_unicode
from django.utils.importlib import import_module

from django.db import models
from django.db.models.query import QuerySet
from django.db.models.fields.related import ForeignRelatedObjectsDescriptor
#~ from django import forms
#~ from django.conf.urls.defaults import patterns, url
#~ from django.forms.models import modelform_factory
#~ from django.forms.models import _get_foreign_key
#~ from django.contrib.auth.decorators import login_required
from django.contrib.contenttypes.models import ContentType
#~ from django.contrib.contenttypes import generic

#~ from dateutil import parser as dateparser

from django.http import HttpResponse
from django.utils.safestring import mark_safe


import lino
#~ from lino import layouts
from lino.core import fields
from lino.core import actions
from lino.utils import babel
from lino.core.model import Model
from lino.core.modeltools import obj2str
from lino.utils.config import load_config_files, Configured
#~ from lino.core import datalinks
#~ from lino.core import boolean_texts
from lino.core import actors
from lino.core import frames
#~ from lino.core import action_requests
#~ from lino.ui import base

#~ from lino.ui import requests as ext_requests

from lino.core.modeltools import resolve_model, resolve_field, full_model_name, get_field, UnresolvedModel
#~ from lino.utils.config import LOCAL_CONFIG_DIR
from lino.core.modeltools import get_model_report
from lino.core.tables import AbstractTable, TableRequest, VirtualTable
#~ from lino.core.tables import GridEdit #, ComputedColumn


#~ from lino.modlib import field_choices

        

def unused_parse_js_date(s,name):
    #~ v = dateparser.parse(s)
    #~ v = dateparser.parse(s,fuzzy=True)
    return datetime.date(*settings.LINO.parse_date(s))
    #~ print "parse_js_date %s : %r -> %s" % (name,s,v)
    #~ return v
    
    
def wildcard_data_elems(model):
    """
    Yields names that will be used as wildcard column_names of a Table.
    """
    meta = model._meta
    #~ for f in meta.fields: yield f.name
    #~ for f in meta.many_to_many: yield f.name
    #~ for f in meta.virtual_fields: yield f.name
    for f in meta.fields: 
        #~ if f.editable:
        if not isinstance(f,fields.VirtualField):
            if not getattr(f,'_lino_babel_field',False):
                yield f
    for f in meta.many_to_many: yield f
    for f in meta.virtual_fields: 
        if not isinstance(f,fields.VirtualField):
            yield f
    # todo: for slave in self.report.slaves
  
    #~ for de in data_elems(self.model): yield de
    


#~ def summary_row(obj,ui,rr,**kw):
def summary_row(obj,ar,**kw):
    return obj.summary_row(ar,**kw)
    #~ m = getattr(obj,'summary_row',None)
    #~ if m:
        #~ return m(ar,**kw)
    #~ return ar.renderer.href_to(obj)
    #~ return ar.ui.ext_renderer.href_to(obj)
  

#~ def summary(ui,rr,separator=', ',max_items=5,before='',after='',**kw):
def summary(ar,objects,separator=', ',max_items=5,before='',after='',**kw):
    """
    Returns this table as a unicode string.
    
    :param max_items: don't include more than the specified number of items.
    """
    #~ if format is None:
        #~ def format(rr,obj):
            #~ return unicode(obj)
    s = u''
    n = 0
    #~ for i in rr.data_iterator:
    for i in objects:
        if n:
            s += separator
        else:
            s += before
        n += 1
        #~ s += summary_row(i,ui,rr,**kw)
        s += ar.summary_row(i,**kw)
        #~ s += i.summary_row(ui,rr,**kw)
        if n >= max_items:
            s += separator + '...' + after
            return s
    if n:
        return s + after
    return s

#~ def default_summary_row(obj,rr):
    #~ return u'<a href="%s" target="_blank">%s</a>' % (rr.get_request_url(str(obj.pk),fmt='detail'),unicode(obj))
    #~ return u'<span onClick="foo">%s</span>' % (ui.get_actor_url(self,str(obj.pk)),unicode(obj))
    #~ return u'<a href="#" onclick="Lino.foo">%s</a>' % unicode(obj)
        


def base_attrs(cl):
    #~ if cl is Table or len(cl.__bases__) == 0:
        #~ return
    #~ myattrs = set(cl.__dict__.keys())
    for b in cl.__bases__:
        for k in base_attrs(b):
            yield k
        for k in b.__dict__.keys():
            yield k


def add_quick_search_filter(qs,search_text):
    if not isinstance(qs,QuerySet): 
        # TODO: filter also simple lists 
        return qs
    return qs.filter(quick_search_filter(qs.model,search_text))
    
def quick_search_filter(model,search_text,prefix=''):
    #~ logger.info("20120709 add_quick_search_filter(%s,%r)",qs.model,search_text)
    q = models.Q()
    if model.quick_search_fields is not None:
        for fn in model.quick_search_fields:
            kw = {prefix+fn+"__icontains": search_text}
            q = q | models.Q(**kw)
            #~ logger.info("20120709 %s__icontains=%r",fn,search_text)
    else:
        for field in model._meta.fields:
            if isinstance(field,models.CharField):
                kw = {prefix+field.name+"__icontains": search_text}
                q = q | models.Q(**kw)
                #~ logger.info("20120709 %s__icontains=%r",field.name,search_text)
            #~ else:
                #~ logger.info("20120709 %s : not a CharField",field.name)
    if search_text.isdigit():
        for field in model._meta.fields:
            if isinstance(field,(models.IntegerField,models.AutoField)):
                kw = {prefix+field.name: int(search_text)}
                q = q | models.Q(**kw)
    return q
    
def add_gridfilters(qs,gridfilters):
    """
    Converts a `filter` request in the format used by :extux:`Ext.ux.grid.GridFilters` into a 
    `Django field lookup <http://docs.djangoproject.com/en/1.2/ref/models/querysets/#field-lookups>`_
    on a :class:`django.db.models.query.QuerySet`.
    
    :param qs: the queryset to be modified.
    :param gridfilters: a list of dictionaries, each having 3 keys `field`, `type` and `value`.
    
    """
    if not isinstance(qs,QuerySet): 
        raise NotImplementedError('TODO: filter also simple lists')
    q = models.Q()
    for flt in gridfilters:
        field = get_field(qs.model,flt['field'])
        flttype = flt['type']
        kw = {}
        if flttype == 'string':
            if isinstance(field,models.CharField):
                kw[field.name+"__icontains"] =  flt['value']
                q = q & models.Q(**kw)
            elif isinstance(field,models.ForeignKey):
                q = q & quick_search_filter(field.rel.to,flt['value'],field.name+"__")
                #~ rq = models.Q()
                #~ search_field = field.rel.to.grid_search_field
                #~ for search_field in field.rel.to.quick_search_fields:
                #~ search_field = getattr(field.rel.to,'grid_search_field',None)
                #~ if search_field is not None:
                    #~ rq = rq | models.Q(**{field.name+"__%s__icontains" % search_field : flt['value']})
                #~ q = q & rq
            else:
                raise NotImplementedError(repr(flt))
        elif flttype == 'numeric':
            cmp = str(flt['comparison'])
            if cmp == 'eq': cmp = 'exact'
            kw[field.name+"__"+cmp] = flt['value']
            q = q & models.Q(**kw)
        elif flttype == 'boolean':
            kw[field.name+"__equals"] = flt['value']
            q = q & models.Q(**kw)
        elif flttype == 'date':
            v = datetime.date(*settings.LINO.parse_date(flt['value']))
            #~ v = parse_js_date(flt['value'],field.name)
            cmp = str(flt['comparison'])
            if cmp == 'eq': cmp = 'exact'
            kw[field.name+"__"+cmp] = v
            q = q & models.Q(**kw)
            #~ print kw
        else:
            raise NotImplementedError(repr(flt))
    return qs.filter(q)
        

def rc_name(rptclass):
    return rptclass.app_label + '.' + rptclass.__name__
    
#~ def de_verbose_name(de):
    #~ if isinstance(de,models.Field):
        #~ return de.verbose_name
    #~ return de.name

    
    
# TODO : move these global variables to LinoSite
master_reports = []
slave_reports = []
generic_slaves = {}
frames_list = []
custom_tables = []
#~ rptname_choices = []

config_dirs = []

  
def register_frame(frm):
    frames_list.append(frm)
    
def register_report(rpt):
    #~ logger.debug("20120103 register_report %s", rpt.actor_id)
    #rptclass.app_label = rptclass.__module__.split('.')[-2]
    
    #~ if rpt.typo_check:
        #~ myattrs = set(rpt.__dict__.keys())
        #~ for attr in base_attrs(rpt):
            #~ myattrs.discard(attr)
        #~ if len(myattrs):
            #~ logger.warning("%s defines new attribute(s) %s", rpt, ",".join(myattrs))
            
    if issubclass(rpt,Table) and rpt.model is None:
        #~ logger.debug("20111113 %s is an abstract report", rpt)
        return
        
    #~ for name,v in rpt.__dict__.items():
    #~ for name in rpt.__class__.__dict__.keys():
    #~ for name in dir(rpt):
        #~ v = getattr(rpt,name)
        #~ if isinstance(v,Group):
            #~ v.name = name
            #~ v.add_to_table(rpt)
            #~ rpt.custom_groups = rpt.custom_groups + [v]
        #~ if isinstance(v,ComputedColumn):
            #~ v.name = name
            #~ v.add_to_table(rpt)
            #~ d = dict()
            #~ d.update(rpt.computed_columns)
            #~ d[name] = v
            #~ rpt.computed_columns = d
            
    #~ if rpt.model._meta.abstract:
        
    #~ rptname_choices.append((rpt.actor_id, rpt.get_label()))
    #~ rptname_choices.append(rpt.actor_id)
    
    if issubclass(rpt,Table):
        if rpt.master is None:
            if not rpt.model._meta.abstract:
                #~ logger.debug("20120102 register %s : master report", rpt.actor_id)
                master_reports.append(rpt)
            if not rpt.filter and not rpt.exclude and not rpt.known_values and rpt.use_as_default_table:
                #~ logger.info("register %s : model_report for %s", rpt.actor_id, full_model_name(rpt.model))
                if not rpt.model.__dict__.has_key('_lino_default_table'):
                    rpt.model._lino_default_table = rpt
        elif rpt.master is ContentType:
            #~ logger.debug("register %s : generic slave for %r", rpt.actor_id, rpt.master_key)
            generic_slaves[rpt.actor_id] = rpt
        else:
            #~ logger.debug("20120102 register %s : slave for %r", rpt.actor_id, rpt.master_key)
            slave_reports.append(rpt)
    elif issubclass(rpt,VirtualTable):
        custom_tables.append(rpt)

    

def discover():
    """
    - Each model can receive a number of "slaves". 
      Slaves are tables whose data depends on an instance 
      of another model (their master).
      
    - For each model we want to find out the "default table".
      The "choices table" for a foreignkey field is also currently 
      simply the pointed model's
      model_table.
      :modattr:`_lino_default_table`

    """
              
    logger.debug("Analyzing Tables...")
    #~ logger.debug("20111113 Register Table actors...")
    for rpt in actors.actors_list:
        if issubclass(rpt,Table) and rpt is not Table:
            register_report(rpt)
        elif issubclass(rpt,VirtualTable) and rpt is not VirtualTable:
            register_report(rpt)
        if issubclass(rpt,frames.Frame) and rpt is not frames.Frame:
            register_frame(rpt)
            
    logger.debug("Instantiate model tables...")
    for model in models.get_models():
        """Not getattr but __dict__.get because of the mixins.Listings trick."""
        rpt = model.__dict__.get('_lino_default_table',None)
        #~ rpt = getattr(model,'_lino_default_table',None)
        #~ logger.debug('20111113 %s._lino_default_table = %s',model,rpt)
        if rpt is None:
            rpt = table_factory(model)
            register_report(rpt)
            rpt.class_init()
            #~ rpt.collect_actions()
            model._lino_default_table = rpt
            
            
    logger.debug("Analyze %d slave tables...",len(slave_reports))
    for rpt in slave_reports:
        rpt.master = resolve_model(rpt.master)
        slaves = getattr(rpt.master,"_lino_slaves",None)
        if slaves is None:
            slaves = {}
            rpt.master._lino_slaves = slaves
        slaves[rpt.actor_id] = rpt
        #~ logger.debug("20111113 %s: slave for %s",rpt.actor_id, rpt.master.__name__)
    #~ logger.debug("Assigned %d slave reports to their master.",len(slave_reports))
        
    #~ logger.debug("reports.setup() done")



      

        
        
def has_fk(rr,name):
    if isinstance(rr,TableRequest):
        return rr.actor.master_key == name
    return False

        
#~ def model2report(m):
def model2actor(m):
    def f(table,*args):
        return m(*args)
    return classmethod(f)





class Table(AbstractTable):
    """
    An :class:`AbstractTable` that works on a Django 
    Model using a Django QuerySet.
    
    A Table definition adds attributes
    like `model` and `master` and `master_key` 
    who are important because Lino handles relations automagically.
    
    Another class of attributes are
    `filter`, 'exclude' and `sort_order` 
    which it simply forwards to the QuerySet.
    
    """
    #~ hide_details = []
    #~ """
    #~ A list of base classes whose `.dtl` files should not be loaded for this report.
    #~ """
    
    model = None
    """
    The model on which this table iterates.
    """
    
    show_detail_navigator = True
    
    #~ base_queryset = None 
    #~ """Internally used to store one Queryset instance that is reused for each request.
    #~ Didn't yet measure this, but I believe that this is important for performance 
    #~ because Django then will cache database lookups.
    #~ """
    
    #~ default_params = {}
    """See :doc:`/blog/2011/0701`.
    """
    
    use_as_default_table = True
    """
    Set this to False if this Table should *not* become the Model's default table.
    """
    
    expand_memos = False
    """
    (No longer used; see :doc:`/tickets/44`). 
    Whether multi-line text fields in Grid views should be expanded in by default or not.
    """
    
    #~ can_add = perms.is_authenticated
    #~ """
    #~ A permission descriptor that defines who can add (create) rows in this table.
    #~ """
    
    
    handle_uploaded_files = None
    """
    Handler for uploaded files.
    Same remarks as for :attr:`lino.core.actors.Actor.disabled_fields`.
    """
    
    
    @classmethod
    def request(self,ui=None,request=None,action=None,**kw):
        if action is None:
            action = self.default_action
            assert action is not None
        return TableRequest(ui,self,request,action,**kw)
        
    @classmethod
    def column_choices(self):
        return [ de.name for de in self.wildcard_data_elems() ]
          
    #~ @classmethod
    #~ def elem_filename_root(cls,elem):
        #~ return elem._meta.app_label + '.' + elem.__class__.__name__ + '-' + str(elem.pk)

    @classmethod
    def get_detail_sets(self):
        """
        Yield a list of (app_label,name) tuples for which the kernel 
        should try to create a Detail Set.
        """
        if self.model is not None:
            def yield_model_detail_sets(m):
                for b in m.__bases__:
                    if issubclass(b,models.Model) and b is not models.Model:
                        for ds in yield_model_detail_sets(b):
                            yield ds
                yield m._meta.app_label + '/' + m.__name__
          
            for ds in yield_model_detail_sets(self.model):
                yield ds
            
        for s in super(Table,self).get_detail_sets():
            yield s
            
    #~ @classmethod
    #~ def find_field(cls,model,name):
        #~ for vf in cls.model._meta.virtual_fields:
            #~ if vf.name == name:
                #~ return vf
        #~ return cls.model._meta.get_field(name)
    
    @classmethod
    def get_row_by_pk(self,pk):
        try:
            return self.model.objects.get(pk=pk)
        except ValueError:
            return None
            #~ msg = "Invalid primary key %r for %s." % (pk,self)
            #~ raise Http404(msg)
        except self.model.DoesNotExist:
            return None
            #~ raise Http404("%s %s does not exist." % (self,pk))
            
    @classmethod
    def disabled_actions(self,ar,obj):
        d = dict()
        if obj is not None:
            state = self.get_row_state(obj)
            #~ u = ar.get_user()
            for ba in self.get_actions(ar.bound_action.action):
                if ba.action.action_name:
                    if ba.action.show_in_bbar and not self.get_row_permission(obj,ar,state,ba):
                    #~ if ba.action.show_in_bbar and not obj.get_row_permission(u,state,ba.action):
                    #~ if a.show_in_bbar and not a.get_action_permission(ar.get_user(),obj,state):
                        d[ba.action.action_name] = True
                #~ if ba.action.action_name == 'do_clear_cache':
                    #~ logger.info("20121127 %s %s", obj, d)
            #~ if obj.__class__.__name__ == 'Note':
                #~ logger.info("20120920 %s %s %r", obj, d,obj.__class__.get_row_permission)
        return d
        
            
                
            
    @classmethod
    def wildcard_data_elems(self):
        return wildcard_data_elems(self.model)
          
                    
    @classmethod
    def is_valid_row(self,row):
        return isinstance(row,self.model)
        
    @classmethod
    def get_actor_label(self):
        if self.model is None:
            return self.__name__
        return self.model._meta.verbose_name_plural
        
    @classmethod
    def class_init(self):
      
        if self.model is not None:
            self.model = resolve_model(self.model,self.app_label)
            
        if isinstance(self.model,UnresolvedModel):
            self.model = None
            
        if self.model is not None:
            if isinstance(self.hidden_columns,basestring):
                self.hidden_columns = frozenset(fields.fields_list(self.model,self.hidden_columns))
            self.hidden_columns = self.hidden_columns | self.model.hidden_columns
            self.hidden_elements = self.hidden_elements | self.model.hidden_elements
            #~ if self.model.__name__ == 'Partner':
                #~ print "20130124 class_init ", self,self.hidden_elements
            #~ if self.hidden_elements is None:
                #~ self.hidden_elements = self.model.hidden_elements
            #~ if isinstance(self.hidden_elements,basestring):
                #~ self.hidden_elements = fields.fields_list(self.model,self.hidden_elements)
                
            #~ for name,action in self.model.get_model_actions(self):
                #~ existing_value = self.__dict__.get(name,None)
                #~ if existing_value is not None:
                    #~ if not isinstance(existing_value,actions.Action):
                        #~ raise Exception(
                            #~ "%s cannot get model action %s because name is already used for %r" %
                            #~ self,name,existing_value)
                #~ else:
                    #~ setattr(self,name,action)
            
            
        super(Table,self).class_init()
        #~ if self.model is None:
            #~ if self.base_queryset is not None:
                #~ self.model = self.base_queryset.model
            # raise Exception("No model in %s" %  self)
        #~ else:
            #~ self.model = resolve_model(self.model,self.app_label)
            
        #~ logger.debug("20120731 class_init(%r) : model is %s",self,self.model)
        
        
        if self.model is not None:
              
            #~ for b in self.model.mro():
                #~ for k,v in b.__dict__.items():
                    #~ if isinstance(v,actions.Action):
                        #~ raise Exception("20130121 Must convert %s.%s to get_model_actions()" % (self.model,k))
            if True:
                for b in self.model.mro():
                    for k,v in b.__dict__.items():
                        if isinstance(v,actions.Action):
                            existing_value = self.__dict__.get(k,None)
                            if existing_value is not None:
                                if not isinstance(existing_value,actions.Action):
                                    raise Exception(
                                        "%s cannot get model action %s because name is already used for %r" %
                                        self,k,existing_value)
                                #~ if self.__dict__.has_key(k):
                                #~ """
                                #~ Actions defined in 
                                #~ If a Table has an attribute
                                #~ When there is an Action called `foo` 
                                #~ """
                                #~ logger.debug("Not overriding %s.%s from %s",self,k,b)
                                #~ pass
                            else:
                                #~ 20130121 : removed two following lines 
                                #~ v = copy.deepcopy(v)
                                #~ v.name = None
                                
                                #~ def meth(action,ar,elem):
                                #~     return v.run()
                                #~ v.run = meth
                                setattr(self,k,v)
                      
          
            #~ ma = getattr(self.model,'_lino_model_actions',None)
            #~ if ma is not None:
                #~ for k,v in ma.items():
                    #~ v = copy.deepcopy(v)
                    #~ v.name = None
                    #~ setattr(self,k,v)
                    
                    
              
            for name in ('workflow_state_field','workflow_owner_field'):
                if getattr(self,name) is None:
                    setattr(self,name,getattr(self.model,name))
                    #~ v = getattr(self.model,name,None)
                    #~ if v is not None:
                        #~ setattr(self,name,v)
                        
            for name in ( #'disabled_fields',
                         'handle_uploaded_files', 
                         #~ 'get_row_permission', 
                         #~ 'disable_editing',
                         ):
                if getattr(self,name) is None:
                    m = getattr(self.model,name,None)
                    if m is not None:
                        #~ logger.debug('20120731 Install model method %s from %r to %r',name,self.model,self)
                        setattr(self,name,model2actor(m))
                        #~ 'dictproxy' object does not support item assignment:
                        #~ self.__dict__[name] = model2actor(m) 
                        
            if self.master_key:
                #~ assert self.model is not None, "%s has .master_key but .model is None" % self
                #~ self.master = resolve_model(self.master,self.app_label)
                master_model = None
                try:
                    fk, remote, direct, m2m = self.model._meta.get_field_by_name(self.master_key)
                    assert direct
                    assert not m2m
                    #~ if fk.rel is None:
                        #~ raise Exception("%s.master_key %r is not a RelatedField" % (self,self.master_key))
                    if fk.rel is not None:
                        master_model = fk.rel.to
                except models.FieldDoesNotExist,e:
                    #~ logger.debug("FieldDoesNotExist in %r._meta.get_field_by_name(%r)",self.model,self.master_key)
                    for vf in self.model._meta.virtual_fields:
                        if vf.name == self.master_key:
                            fk = vf
                            master_model = ContentType
                            break
                if master_model is None:
                    raise Exception("%s : no master for master_key %r in %s" % (
                        self,self.master_key,self.model.__name__))
                self.master = master_model
                #~ self.fk = fk
                self.master_field = fk
        #~ else:
            #~ assert self.master is None
        
        
        if self.order_by is not None:
            if not isinstance(self.order_by,(list,tuple)):
                raise Exception("%s.order_by is %r (must be a list or tuple)" % (self,self.order_by))
            if False: 
              # good idea, but doesn't yet work for foreign fields, 
              # e.g. order_by = ['content_type__app_label']
              for fieldname in self.order_by:
                  if fieldname.startswith('-'):
                      fieldname = fieldname[1:]
                  try:
                      fk, remote, direct, m2m = self.model._meta.get_field_by_name(fieldname)
                      assert direct
                      assert not m2m
                  except models.FieldDoesNotExist,e:
                      raise Exception("Unknown fieldname %r in %s.order_by" % (fieldname,self))
        
    @classmethod
    def do_setup(self):
            
        super(Table,self).do_setup()
        #~ AbstractTable.do_setup(self)
        if self.model is None:
            return 
            
        if hasattr(self.model,'_lino_slaves'):
            self._slaves = self.model._lino_slaves.values()
        else:
            self._slaves = []
            
        #~ m = getattr(self.model,'setup_report',None)
        #~ if m:
            #~ m(self)
        m = getattr(self.model,'setup_table',None)
        if m is not None:
            m(self)
        
    @classmethod
    def is_abstract(self):
        if self.model is None \
            or self.model is Model \
            or self.model._meta.abstract:
            #~ logger.info('20120621 %s : no real table',h)
            return True
        return False
          
    #~ @classmethod
    #~ def setup_permissions(self):
        #~ if self.model is not None:
        #~ super(Table,self).setup_permissions()
        
    @classmethod
    def disabled_fields(cls,obj,ar):
        return obj.disabled_fields(ar)
        
        
    @classmethod
    def get_row_permission(cls,obj,ar,state,ba):
        """
        Returns True if the given action is allowed for the given instance `obj` 
        and the given user.
        """
        #~ logger.info("20121020 dbtables.Table.get_row_permission %s",unicode(ba.action.label))
        return obj.get_row_permission(ar,state,ba)
        
    @classmethod
    def disable_delete(self,obj,ar):
        """
        Return either `None` if the given `obj` *is allowed* 
        to be deleted by action request `ar`,
        or a string with a message explaining why, if not.
        """
        #~ logger.info("20130225 dbtables.disable_delete")
        if self.delete_action is None:
            return "No delete_action"
        if not self.get_row_permission(obj,ar,self.get_row_state(obj),self.delete_action):
            #~ print "20130222 ar is %r" % ar
            #~ logger.info("20130225 dbtables.disable_delete no permission")
            return _("You have no permission to delete this row.")
        return obj.disable_delete(ar)
        


    @classmethod
    def get_data_elem(self,name):
        """
        Adds the possibility to specify 
        :class:`remote fields <lino.core.fields.RemoteField>`
        in a layout template.
        """
        de = super(Table,self).get_data_elem(name)
        #~ cc = AbstractTable.get_data_elem(self,name)
        if de:
            return de
            
        if self.model is None:
            return None
        if not isinstance(self.model,type) or not issubclass(self.model,models.Model):
            raise Exception("%s.model is %r (and not a Model subclass)" % (self,self.model))
            
            
            
        # logger.info("20120202 Table.get_data_elem found nothing")
        return fields.get_data_elem(self.model,name)
        #~ de = get_data_elem(self.model,name)
        #~ if de is not None: 
            #~ return de
        #~ return self.get_action(name)
        
        
    #~ @classmethod
    #~ def get_detail(self):
        #~ return self.model._lino_detail
        
        
    @classmethod
    def get_title(self,ar):
        # NOTE: similar code in tables
        title = self.get_title_base(ar)
        tags = list(self.get_title_tags(ar))
        if len(tags):
            title += " (%s)" % (', '.join(tags))
        return title
        
        
    @classmethod
    def get_title_base(self,ar):
        title = self.title or self.label
        if self.master is not None:
            title = _("%(details)s of %(master)s") % dict(
              details=title,
              master=ar.master_instance)
        return title
        
    @classmethod
    def get_queryset(self):
        """
        Return an iterable over the items processed by this report.
        Override this to use e.g. select_related()
        or to return a list.
        """
        return self.model.objects.all()
      
    @classmethod
    def get_request_queryset(self,rr):
        """
        Build a Queryset for the specified request on this table.
        Upon first call, this will also lazily install Table.queryset 
        which will be reused on every subsequent call.
        """
        #~ See 20120123
        #~ from lino.modlib.jobs.models import Jobs
        #~ if rr.report is Jobs:
            #~ logger.info("20120123 get_request_queryset()")
        #~ qs = self.__dict__.get('base_queryset',None)
        #~ if qs is None:
            #~ qs = self.base_queryset = self.get_queryset()
            #~ if rr.report is Jobs:
                #~ logger.info("20120123 Setting base_queryset")
        qs = self.get_queryset()
        #~ kw = self.get_filter_kw(rr.master_instance,**rr.params)
        kw = self.get_filter_kw(rr.master_instance)
        if kw is None:
            return []
        if len(kw):
            qs = qs.filter(**kw)

        if rr.exclude:
            qs = qs.exclude(**rr.exclude)
            #~ qs = qs.exclude(rr.exclude)
            
        if self.filter:
            #~ qs = qs.filter(**self.filter)
            qs = qs.filter(self.filter)
            
        if rr.filter:
            #~ print rr.filter
            #~ qs = qs.filter(**rr.filter)
            qs = qs.filter(rr.filter)
            
        if rr.known_values:
            #~ logger.info("20120111 known values %r",rr.known_values)
            d = {}
            for k,v in rr.known_values.items():
                if v is None:
                    d[k+"__isnull"] = True
                else:
                    #~ d[k+"__exact"] = v
                    d[k] = v
                qs = qs.filter(**d)
                
        if self.exclude:
            qs = qs.exclude(**self.exclude)
              
        if rr.quick_search is not None:
            #~ qs = add_quick_search_filter(qs,self.model,rr.quick_search)
            qs = add_quick_search_filter(qs,rr.quick_search)
        if rr.gridfilters is not None:
            qs = add_gridfilters(qs,rr.gridfilters)
        extra = rr.extra or self.extra
        if extra is not None:
            qs = qs.extra(**extra)
        order_by = rr.order_by or self.order_by
        if order_by:
            #~ logger.info("20120122 order_by %s",order_by)
            qs = qs.order_by(*order_by)
        return qs

    @classmethod
    def create_instance(self,ar,**kw):
        #~ print 20120630, "Actor.create_instance", kw
        instance = self.model(**kw)
        #~ self.on_create(instance,ar)
        
        instance.on_create(ar)
        #~ m = getattr(instance,'on_create',None)
        #~ if m:
            #~ m(ar)
        return instance
        
    @classmethod
    def slave_as_summary_meth(self,ui,row_separator):
        """
        Creates and returns the method to be used when 
        :attr:`AbstractTable.slave_grid_format` is 'summary'.
        """
        def meth(master,ar):
            #~ print 20120715, ar
            ar = ar.spawn(self,master_instance=master)
            #~ ar = self.request(ui,None,master_instance=master)
            s = summary(ar,ar.data_iterator,row_separator)
            return s
        return meth
        
        
    #~ @classmethod
    #~ def ajax_update(self,request):
        #~ print request.POST
        #~ return HttpResponse("1", mimetype='text/x-json')







def table_factory(model):
    """
    Automatically define a Table class for the specified model.
    This is used during kernel setup to create default tables for 
    models who have no Table.
    """
    #~ logger.info('table_factory(%s)',model.__name__)
    bases = (Table,)
    for b in model.__bases__:
        rpt = getattr(b,'_lino_default_table',None)
        if rpt is not None:
            if issubclass(model,rpt.model):
            #~ if issubclass(rpt.model,model):
                bases = (rpt,)
                #~ bases = (rpt.__class__,)
    #~ logger.info('table_factory(%s) : bases is %s',model.__name__,bases)
    app_label = model._meta.app_label
    name = model.__name__ + "Table"
    cls = type(name,bases,dict(model=model,app_label=app_label))
    #~ cls.class_init()
    #~ cls.setup()
    
    #~ """
    #~ 20120104 We even add the factored class to the module because 
    #~ actor lookup needs it. Otherwise we'd get a 
    #~ `'module' object has no attribute 'DataControlListingTable'` error.
    
    #~ We cannot simply do ``settings.LINO.modules.define(app_label,name,cls)``
    #~ because this code is executed when `settings.LINO.modules` doesn't yet exist.
    #~ """
    
    #~ m = import_module(model.__module__)
    #~ if getattr(m,name,None) is not None:
        #~ raise Exception(
          #~ "Name of factored class %s clashes with existing name in %s" 
          #~ %(cls,m))
    #~ setattr(m,name,cls)
    return actors.register_actor(cls)


def column_choices(rptname):
    rpt = actors.get_actor(rptname)
    return rpt.column_choices()


        
