from urllib.parse import urlparse

from django.contrib.sites.models import Site
from django.http import HttpResponse
from django.urls import resolve, Resolver404
from micropub import error

from .models import Entry


def from_url(url: str) -> Entry:
    domain = Site.objects.get_current().domain
    if not url:
        raise error.bad_req("url parameter required")
    if "//" not in url:
        url = "//" + url
    parts = urlparse(url, scheme="https")
    if parts.scheme not in ("http", "https") or parts.netloc != domain:
        raise error.bad_req("url does not point to this site")

    try:
        match = resolve(parts.path)
    except Resolver404:
        raise error.bad_req("url does not point to a valid page on this site")

    if match.view_name != "entries:entry":
        raise error.bad_req("url does not point to an entry on this site")

    try:
        entry = Entry.objects.get(pk=match.kwargs["id"])
    except Entry.DoesNotExist:
        raise error.bad_req("url does not point to an existing entry")

    return entry