from rest_framework import status
from rest_framework.response import Response

from django.db import IntegrityError
from django.utils.translation import gettext as _

from misago.users.namechanges import get_username_options
from misago.users.serializers import ChangeUsernameSerializer


def username_endpoint(request):
    if request.method == 'POST':
        return change_username(request)
    else:
        options = get_username_options_from_request(request)
        return options_response(options)


def get_username_options_from_request(request):
    return get_username_options(
        request.settings, request.user, request.user_acl
    )


def options_response(options):
    if options['next_on']:
        options['next_on'] = options['next_on'].isoformat()
    return Response(options)


def change_username(request):
    options = get_username_options_from_request(request)
    if not options['changes_left']:
        return Response(
            {
                'detail': _("You can't change your username now."),
                'options': options
            },
            status=status.HTTP_400_BAD_REQUEST
        )

    serializer = ChangeUsernameSerializer(
        data=request.data,
        context={'settings': request.settings, 'user': request.user},
    )
    if serializer.is_valid():
        try:
            serializer.change_username(changed_by=request.user)
            updated_options = get_username_options_from_request(request)
            if updated_options['next_on']:
                updated_options['next_on'] = updated_options['next_on'].isoformat()

            return Response({
                'username': request.user.username,
                'slug': request.user.slug,
                'options': updated_options,
            })
        except IntegrityError:
            return Response(
                {
                    'detail': _("Error changing username. Please try again."),
                },
                status=status.HTTP_400_BAD_REQUEST
            )
    else:
        return Response(
            {
                'detail': serializer.errors['non_field_errors'][0]
            },
            status=status.HTTP_400_BAD_REQUEST
        )


def moderate_username_endpoint(request, profile):
    if request.method == 'POST':
        serializer = ChangeUsernameSerializer(
            data=request.data,
            context={'settings': request.settings, 'user': profile},
        )

        if serializer.is_valid():
            try:
                serializer.change_username(changed_by=request.user)
                return Response({
                    'username': profile.username,
                    'slug': profile.slug,
                })
            except IntegrityError:
                return Response(
                    {
                        'detail': _("Error changing username. Please try again."),
                    },
                    status=status.HTTP_400_BAD_REQUEST
                )
        else:
            return Response(
                {
                    'detail': serializer.errors['non_field_errors'][0]
                },
                status=status.HTTP_400_BAD_REQUEST
            )
    else:
        return Response({
            'length_min': request.settings.username_length_min,
            'length_max': request.settings.username_length_max,
        })