"""Public redirect — no auth. SMS recipients tap GET /<code>."""

from __future__ import annotations

import re

from django.http import Http404, HttpResponseRedirect
from django.views.decorators.http import require_http_methods

from links.models import ShortLink
from links.services import record_click_best_effort

CODE_RE = re.compile(r"^[a-z0-9]{4,8}$")


@require_http_methods(["GET", "HEAD"])
def redirect_view(request, code: str):
    if not CODE_RE.fullmatch(code):
        raise Http404()

    try:
        link = ShortLink.objects.get(code=code)
    except ShortLink.DoesNotExist as exc:
        raise Http404() from exc

    if not link.is_available():
        raise Http404()

    if request.method == "GET":
        record_click_best_effort(request, link)
    return HttpResponseRedirect(link.target_url)