from django.conf import settings
from django.http import HttpRequest, HttpResponse
from django.shortcuts import redirect
from django.utils.translation import ugettext as _

from zerver.decorator import require_realm_admin
from zerver.lib.actions import do_change_icon_source
from zerver.lib.realm_icon import realm_icon_url
from zerver.lib.response import json_error, json_success
from zerver.lib.upload import upload_icon_image
from zerver.lib.url_encoding import add_query_arg_to_redirect_url
from zerver.models import UserProfile


@require_realm_admin
def upload_icon(request: HttpRequest, user_profile: UserProfile) -> HttpResponse:

    if len(request.FILES) != 1:
        return json_error(_("You must upload exactly one icon."))

    icon_file = list(request.FILES.values())[0]
    if ((settings.MAX_ICON_FILE_SIZE * 1024 * 1024) < icon_file.size):
        return json_error(_("Uploaded file is larger than the allowed limit of {} MiB").format(
            settings.MAX_ICON_FILE_SIZE,
        ))
    upload_icon_image(icon_file, user_profile)
    do_change_icon_source(user_profile.realm, user_profile.realm.ICON_UPLOADED, acting_user=user_profile)
    icon_url = realm_icon_url(user_profile.realm)

    json_result = dict(
        icon_url=icon_url,
    )
    return json_success(json_result)


@require_realm_admin
def delete_icon_backend(request: HttpRequest, user_profile: UserProfile) -> HttpResponse:
    # We don't actually delete the icon because it might still
    # be needed if the URL was cached and it is rewritten
    # in any case after next update.
    do_change_icon_source(user_profile.realm, user_profile.realm.ICON_FROM_GRAVATAR, acting_user=user_profile)
    gravatar_url = realm_icon_url(user_profile.realm)
    json_result = dict(
        icon_url=gravatar_url,
    )
    return json_success(json_result)


def get_icon_backend(request: HttpRequest, user_profile: UserProfile) -> HttpResponse:
    url = realm_icon_url(user_profile.realm)

    # We can rely on the url already having query parameters. Because
    # our templates depend on being able to use the ampersand to
    # add query parameters to our url, get_icon_url does '?version=version_number'
    # hacks to prevent us from having to jump through decode/encode hoops.
    url = add_query_arg_to_redirect_url(url, request.META['QUERY_STRING'])
    return redirect(url)