import json
from collections import namedtuple
from os.path import join
from types import SimpleNamespace

from django import template
from django.conf import settings
from django.urls import reverse

register = template.Library()
cache = SimpleNamespace(package_json=None)


class MenuItem:
    def __init__(self, label, icon, url):
        self.label = label
        self.icon = icon
        self.url = reverse(url)


@register.simple_tag
def get_package_json():
    if cache.package_json:
        return cache.package_json
    with open(join(settings.BASE_DIR, 'package.json')) as f:
        cache.package_json = json.load(f)
    return cache.package_json


@register.simple_tag
def site_name():
    return settings.LEMONCURRY_SITE_NAME


@register.inclusion_tag('lemoncurry/tags/nav.html')
def nav_left():
    items = ()
    return {'items': items}


@register.inclusion_tag('lemoncurry/tags/nav.html')
def nav_right(request):
    if request.user.is_authenticated():
        items = (
            MenuItem(label='admin', icon='fa fa-gear', url='admin:index'),
            MenuItem(label='log out', icon='fa fa-sign-out', url='lemonauth:logout'),
        )
    else:
        items = (
            MenuItem(label='log in', icon='fa fa-sign-in', url='lemonauth:login'),
        )
    return {'items': items}