from django.core.exceptions import PermissionDenied
from django.utils.translation import ugettext as _

from rest_framework import status
from rest_framework.response import Response

from misago.conf import settings
from misago.core.utils import format_plaintext_for_html

from misago.users.forms.options import EditSignatureForm
from misago.users.signatures import is_user_signature_valid, set_user_signature


def signature_endpoint(request):
    user = request.user

    if not user.acl['can_have_signature']:
        raise PermissionDenied(
            _("You don't have permission to change signature."))

    if user.is_signature_locked:
        if user.signature_lock_user_message:
            reason = format_plaintext_for_html(
                user.signature_lock_user_message)
        else:
            reason = None

        return Response({
                'detail': _("Your signature is locked. You can't change it."),
                'reason': reason
            },
            status=status.HTTP_403_FORBIDDEN)

    if request.method == 'POST':
        return edit_signature(request, user)

    return get_signature_options(user)


def get_signature_options(user):
    options = {
        'signature': None,
        'limit': settings.signature_length_max,
    }

    if user.signature:
        options['signature'] = {
            'plain': user.signature,
            'html': user.signature_parsed,
        }

        if not is_user_signature_valid(user):
            options['signature']['html'] = None

    return Response(options)


def edit_signature(request, user):
    form = EditSignatureForm(request.data, instance=user)
    if form.is_valid():
        set_user_signature(
                request, user, form.cleaned_data['signature'])
        user.save(update_fields=[
            'signature', 'signature_parsed', 'signature_checksum'
        ])
        return get_signature_options(user)
    else:
        return Response({'detail': form.non_field_errors()[0]},
                        status=status.HTTP_400_BAD_REQUEST)