Nye-TeeOff/frontend/src/app/seo.ts

import type { Metadata } from "next";
import { FALLBACK_IMAGE } from "@/config/constants";
import type { FacilityRecord } from "@/app/facilityData";

type MetadataInput = {
  title: string;
  description: string;
  path?: string;
  image?: string | null;
  type?: "website" | "article";
};

type BreadcrumbItem = {
  name: string;
  path: string;
};

type CollectionPageInput = {
  name: string;
  description: string;
  path: string;
};

type SocialLink = {
  url?: string | null;
};

type FacilitySeoRecord = FacilityRecord & {
  address?: string | null;
  email?: string | null;
  social_links?: unknown;
};

export const SITE_NAME = "TeeOff";
export const SITE_URL = (process.env.NEXT_PUBLIC_SITE_URL || "https://nye.teeoff.no").replace(/\/$/, "");
export const DEFAULT_DESCRIPTION =
  "Oppdatert banestatus, priser, Veien til Golf og informasjon om norske golfanlegg samlet på ett sted.";
export const DEFAULT_OG_IMAGE = buildAbsoluteUrl(FALLBACK_IMAGE);
export const ORGANIZATION_ID = `${SITE_URL}#organization`;
export const WEBSITE_ID = `${SITE_URL}#website`;

const SAME_AS_LINKS = [
  "https://www.facebook.com/TeeOff.norge/",
  "https://twitter.com/TeeOffno",
  "https://www.instagram.com/teeoffno/",
];

export function buildAbsoluteUrl(path = "/") {
  if (!path) return SITE_URL;
  if (/^https?:\/\//i.test(path)) return path;
  return `${SITE_URL}${path.startsWith("/") ? path : `/${path}`}`;
}

export function resolveImageUrl(image?: string | null) {
  if (!image) return DEFAULT_OG_IMAGE;
  return buildAbsoluteUrl(image);
}

export function stripHtml(value: string | null | undefined) {
  return String(value || "")
    .replace(/<[^>]+>/g, " ")
    .replace(/&nbsp;/gi, " ")
    .replace(/\s+/g, " ")
    .trim();
}

export function trimDescription(value: string | null | undefined, maxLength = 160) {
  const plain = stripHtml(value);
  if (plain.length <= maxLength) return plain;
  return `${plain.slice(0, maxLength - 1).trimEnd()}…`;
}

export function createPageMetadata({
  title,
  description,
  path = "/",
  image,
  type = "website",
}: MetadataInput): Metadata {
  const ogImage = resolveImageUrl(image);

  return {
    title,
    description,
    alternates: {
      canonical: path,
    },
    openGraph: {
      type,
      locale: "nb_NO",
      siteName: SITE_NAME,
      title,
      description,
      url: buildAbsoluteUrl(path),
      images: [
        {
          url: ogImage,
          width: 1600,
          height: 900,
          alt: title,
        },
      ],
    },
    twitter: {
      card: "summary_large_image",
      site: "@TeeOffno",
      creator: "@TeeOffno",
      title,
      description,
      images: [ogImage],
    },
  };
}

export function createOrganizationJsonLd() {
  return {
    "@context": "https://schema.org",
    "@type": "Organization",
    "@id": ORGANIZATION_ID,
    name: SITE_NAME,
    url: SITE_URL,
    logo: {
      "@type": "ImageObject",
      url: buildAbsoluteUrl("/icons/cropped-siteicon-1.png"),
    },
    sameAs: SAME_AS_LINKS,
  };
}

export function createWebsiteJsonLd() {
  return {
    "@context": "https://schema.org",
    "@type": "WebSite",
    "@id": WEBSITE_ID,
    url: SITE_URL,
    name: SITE_NAME,
    inLanguage: "nb-NO",
    publisher: {
      "@id": ORGANIZATION_ID,
    },
  };
}

export function createBreadcrumbJsonLd(items: BreadcrumbItem[]) {
  return {
    "@context": "https://schema.org",
    "@type": "BreadcrumbList",
    itemListElement: items.map((item, index) => ({
      "@type": "ListItem",
      position: index + 1,
      name: item.name,
      item: buildAbsoluteUrl(item.path),
    })),
  };
}

export function createCollectionPageJsonLd({ name, description, path }: CollectionPageInput) {
  return {
    "@context": "https://schema.org",
    "@type": "CollectionPage",
    name,
    description,
    url: buildAbsoluteUrl(path),
    inLanguage: "nb-NO",
    isPartOf: {
      "@id": WEBSITE_ID,
    },
    about: {
      "@id": ORGANIZATION_ID,
    },
  };
}

export function createFacilityJsonLd(facility: FacilitySeoRecord) {
  const socialLinks = parseJson<SocialLink[]>(facility.social_links, []);
  const sameAs = [facility.website_url, ...socialLinks.map((entry) => entry?.url || null)].filter(Boolean);

  return {
    "@context": "https://schema.org",
    "@type": "GolfCourse",
    "@id": buildAbsoluteUrl(`/golfbaner/${facility.slug}#golfcourse`),
    name: facility.name,
    description:
      trimDescription(facility.description) ||
      `${facility.name} er et golfanlegg på TeeOff med oppdatert banestatus og praktisk klubbinfo.`,
    url: buildAbsoluteUrl(`/golfbaner/${facility.slug}`),
    image: resolveImageUrl(facility.image_url),
    telephone: facility.phone || undefined,
    email: facility.email || undefined,
    address:
      facility.address || facility.city || facility.county
        ? {
            "@type": "PostalAddress",
            streetAddress: facility.address || undefined,
            addressLocality: facility.city || undefined,
            addressRegion: facility.county || undefined,
            addressCountry: "NO",
          }
        : undefined,
    geo:
      typeof facility.lat === "number" && typeof facility.lng === "number"
        ? {
            "@type": "GeoCoordinates",
            latitude: facility.lat,
            longitude: facility.lng,
          }
        : undefined,
    sameAs: sameAs.length > 0 ? sameAs : undefined,
    isPartOf: {
      "@id": WEBSITE_ID,
    },
  };
}

function parseJson<T>(value: unknown, fallback: T): T {
  if (!value) return fallback;
  if (typeof value === "object") return value as T;
  try {
    return JSON.parse(String(value)) as T;
  } catch {
    return fallback;
  }
}