from django import template

from django.db.models import get_models

from django.utils.encoding import force_unicode

from django.utils.safestring import mark_safe

register = template.Library()

class AdminApplistNode(template.Node):

    def __init__(self, varname):

        self.varname = varname

    def render(self, context):

        from django.db import models

        from django.utils.text import capfirst

        app_list = []

        user = context['user']

        for app in models.get_apps():

            # Determine the app_label.

            app_models = get_models(app)

            if not app_models:

                continue

            app_label = app_models[0]._meta.app_label

            has_module_perms = user.has_module_perms(app_label)

            if has_module_perms:

                model_list = []

                for m in app_models:

                    if m._meta.admin:

                        perms = {

                            'add': user.has_perm("%s.%s" % (app_label, m._meta.get_add_permission())),

                            'change': user.has_perm("%s.%s" % (app_label, m._meta.get_change_permission())),

                            'delete': user.has_perm("%s.%s" % (app_label, m._meta.get_delete_permission())),

                        }

                        # Check whether user has any perm for this module.

                        # If so, add the module to the model_list.

                        if True in perms.values():

                            model_list.append({

                                'name': force_unicode(capfirst(m._meta.verbose_name_plural)),

                                'admin_url': mark_safe(u'%s/%s/' % (force_unicode(app_label), m.__name__.lower())),

                                'perms': perms,

                            })

                if model_list:

                    # Sort using verbose decorate-sort-undecorate pattern

                    # instead of key argument to sort() for python 2.3 compatibility

                    decorated = [(x['name'], x) for x in model_list]

                    decorated.sort()

                    model_list = [x for key, x in decorated]

                    app_list.append({

                        'name': app_label.title(),

                        'has_module_perms': has_module_perms,

                        'models': model_list,

                    })

        context[self.varname] = app_list

        return ''

def get_admin_app_list(parser, token):

    """

    Returns a list of installed applications and models for which the current user

    has at least one permission.

    Syntax::

        {% get_admin_app_list as [context_var_containing_app_list] %}

    Example usage::

        {% get_admin_app_list as admin_app_list %}

    """

    tokens = token.contents.split()

    if len(tokens) < 3:

        raise template.TemplateSyntaxError, "'%s' tag requires two arguments" % tokens[0]

    if tokens[1] != 'as':

        raise template.TemplateSyntaxError, "First argument to '%s' tag must be 'as'" % tokens[0]

    return AdminApplistNode(tokens[2])

register.tag('get_admin_app_list', get_admin_app_list)