from __future__ import unicode_literals

from django.apps import apps
from django.template import Context, Template
from django.urls import reverse
from django.utils.encoding import force_text
from django.utils.safestring import mark_safe
from django.utils.translation import ugettext_lazy as _

from .classes import EventType


class ObjectLinkWidget(object):
    template_string = '<a href="{{ url }}">{{ object_type }}{{ label }}</a>'

    def __init__(self):
        self.template = Template(template_string=self.template_string)

    def render(self, name=None, value=None):
        label = ''
        object_type = ''
        url = None

        if value:
            label = force_text(value)
            object_type = '{}: '.format(value._meta.verbose_name)
            try:
                url = value.get_absolute_url()
            except AttributeError:
                url = None

            if getattr(value, 'is_staff', None) or getattr(value, 'is_superuser', None):
                # Don't display a anchor to for the user details view for
                # superusers and staff, the details view filters them. Staff
                # and admin users are not manageable by the normal user views.
                url = '#'
                return '{}{}'.format(object_type, label)

        return self.template.render(
            context=Context(
                {'label': label, 'object_type': object_type, 'url': url or '#'}
            )
        )


def widget_event_actor_link(context, attribute=None):
    entry = context['object']

    ContentType = apps.get_model(
        app_label='contenttypes', model_name='ContentType'
    )

    if attribute:
        entry = getattr(entry, attribute)

    if entry.actor == entry.target:
        label = _('System')
        url = None
    else:
        label = entry.actor
        content_type = ContentType.objects.get_for_model(model=entry.actor)

        url = reverse(
            viewname='events:events_for_object', kwargs={
                'app_label': content_type.app_label, 'model': content_type.model,
                'object_id': entry.actor.pk
            }
        )

    if url:
        return Template(
            template_string='<a href="{{ url }}">{{ label }}</a>'
        ).render(context=Context({'label': entry.actor, 'url': url}))
    else:
        return label


def widget_event_type_link(context, attribute=None):
    entry = context['object']

    if attribute:
        entry = getattr(entry, attribute)

    return mark_safe(
        '<a href="%(url)s">%(label)s</a>' % {
            'url': reverse(viewname='events:events_by_verb', kwargs={'verb': entry.verb}),
            'label': EventType.get(name=entry.verb)
        }
    )