coding utf-8 from django contrib contenttypes models import ContentTyp

# -*- coding: utf-8

from django.contrib.contenttypes.models import ContentType
from django.core.urlresolvers import reverse
from django.http import HttpResponseRedirect
from django.shortcuts import get_object_or_404

import flash

import variables


class PermissionsError(Exception):
    def __init__(self, msg):
        self.msg = msg
        
class PermissionsOk(Exception): pass


class Permissions(object):
    """
    Examples:
    @Permissions(model=Post, field="pk", delete=True)
    def delete_post(request, post_id):
        post = get_object_or_404(Post, pk=post_id)
        post.delete()
        return HttpResponseRedirect(request.user.show_url())
    """
    def __init__(self, model, field=None, delete=None, edit=None, create=None, owner_field='user'):
        self.model = model
        self.field = field
        self.delete = delete
        self.edit = edit
        self.create = create
        self.owner_field = owner_field
        self.content_type = ContentType.objects.get_for_model(self.model)
        self.activation = getattr(variables, "ACTIVATION", None)
        self.notice_handler = getattr(variables, "NOTICE_HANDLER")
        self.error_handler = getattr(variables, "ERROR_HANDLER")
    
    
    def __call__(self, func):
        self.func = func
        return self.decorate
            
        
    def decorate(self, request, *args, **kwargs):
        self.request = request
        self.args = args
        self.kwargs = kwargs
        try:
            self.is_authorized()
            self.is_banned()
            self.is_moderator()
            
            if self.create:
                self._create()
            elif self.edit:
                self.obj = get_object_or_404(self.model, **{self.field: self.args[0]})
                self._edit()
            elif self.delete:
                self.obj = get_object_or_404(self.model, **{self.field: self.args[0]})
                self._delete()
                
        except PermissionsError, e:
            self.error_handler(e.msg)
            return HttpResponseRedirect(self._redirect_url())
        
        except PermissionsOk:
            return self.func(self.request, *self.args, **self.kwargs)
        
        return self.func(self.request, *self.args, **self.kwargs)

        
    def _redirect_url(self):
        #redirect_url = self.request.META['HTTP_REFERER']
        #if referer == self.request.path:
        redirect_url = "/"
        return redirect_url
        
    def is_authorized(self):
        if self.activation and not self.request.user.is_active:
            raise PermissionsError(u"Please activate your account")
        if not self.request.user.is_authenticated():
            raise PermissionsError(u"Please authorize")
    
    def is_banned(self):
        if self.content_type in self.request.user.ban.sections.all():
            raise PermissionsError(u"You are banned from this section")
        
    def is_moderator(self):
        if self.content_type in self.request.user.moderator.sections.all():
            raise PermissionsOk()
        
    def _create(self):
        pass
    
    def _delete(self):
        if getattr(self.obj, self.owner_field) != self.request.user:
            raise PermissionsError(u"You can't delete others records")
        
    def _edit(self):
        if getattr(self.obj, self.owner_field) != self.request.user:
            raise PermissionsError(u"You can't edit others records")