from hashlib import md5

from django.http import Http404
from django.shortcuts import redirect, render
from django.utils.translation import gettext as _

from rest_framework.decorators import api_view
from rest_framework.response import Response

from misago.conf import settings
from misago.core.cache import cache
from misago.markup import common_flavour


def get_parsed_content(request, setting_name):
    cache_name = 'misago_legal_%s' % setting_name
    cached_content = cache.get(cache_name)

    unparsed_content = settings.get_lazy_setting(setting_name)

    checksum_source = '%s:%s' % (unparsed_content, settings.SECRET_KEY)
    unparsed_checksum = md5(checksum_source).hexdigest()

    if cached_content and cached_content.get('checksum') == unparsed_checksum:
        return cached_content['parsed']
    else:
        parsed = common_flavour(request, None, unparsed_content)['parsed_text']
        cached_content = {
            'checksum': unparsed_checksum,
            'parsed': parsed,
        }
        cache.set(cache_name, cached_content)
        return cached_content['parsed']


def terms_of_service(request, return_dict=False):
    if not (settings.terms_of_service or settings.terms_of_service_link):
        raise Http404()

    if not return_dict and settings.terms_of_service_link:
        return redirect(settings.terms_of_service_link)

    parsed_content = get_parsed_content(request, 'terms_of_service')
    response_dict = {
        'title': settings.terms_of_service_title or _("Terms of service"),
        'link': settings.terms_of_service_link,
        'body': parsed_content,
    }

    if return_dict:
        return response_dict
    else:
        return render(request, 'misago/terms_of_service.html', response_dict)


def privacy_policy(request, return_dict=False):
    if not (settings.privacy_policy or settings.privacy_policy_link):
        raise Http404()

    if not return_dict and settings.privacy_policy_link:
        return redirect(settings.privacy_policy_link)

    parsed_content = get_parsed_content(request, 'privacy_policy')
    response_dict = {
        'title': settings.privacy_policy_title or _("Privacy policy"),
        'link': settings.privacy_policy_link,
        'body': parsed_content,
    }

    if return_dict:
        return response_dict
    else:
        return render(request, 'misago/privacy_policy.html', response_dict)


API_PAGES = {
    'terms-of-service': terms_of_service,
    'privacy-policy': privacy_policy,
}


@api_view(['GET'])
def legal_page(request, page):
    if page not in API_PAGES:
        raise Http404()

    page_dict = API_PAGES.get(page)(request, True)
    page_dict['id'] = page

    return Response(page_dict)