"""Link HQ Site rows to CitySite registry entries (Pengaturan view list)."""

from __future__ import annotations

from apps.farms.models import Site
from apps.sync.models import CitySite


def ensure_hq_site_for_city(city: CitySite) -> Site:
    """
    Ensure the city registry entry has an HQ Site for farm visibility.

    Prefers an existing linked site, then an unlinked site owned by the
    registrar with a matching name (so seeded Sukawarna attaches when
    registered), otherwise creates a new Site.
    """
    existing = Site.objects.filter(city_site=city).first()
    if existing:
        return existing

    owner = city.registered_by
    if owner is None:
        raise ValueError("CitySite.registered_by is required to create an HQ site.")

    site_name = (city.name or city.code or "Site")[:30]
    orphan = (
        Site.objects.filter(user=owner, city_site__isnull=True, site_name__iexact=site_name)
        .order_by("pk")
        .first()
    )
    if orphan is None and city.code:
        # e.g. code "sukawarna" ↔ site_name "Sukawarna"
        orphan = (
            Site.objects.filter(user=owner, city_site__isnull=True, site_name__iexact=city.code)
            .order_by("pk")
            .first()
        )
    if orphan is not None:
        orphan.city_site = city
        orphan.save(update_fields=["city_site", "updated_at"])
        return orphan

    return Site.objects.create(site_name=site_name, user=owner, city_site=city)