import { texts } from '@/texts'

/**
 * Shared helpers for Phase 3 SEO landing pages' `generateMetadata` /
 * JSON-LD. Centralizes the site origin so every landing page (hub,
 * category, city, combo, event) builds canonical URLs and `JsonLd`
 * absolute URLs the same way instead of each redeclaring its own
 * `SITE_URL` constant.
 */

function resolveSiteUrl(raw = process.env.NEXT_PUBLIC_SITE_URL ?? 'https://backoffice.ghabilee.ir') {
  const url = new URL(raw)

  return url.toString().replace(/\/+$/, '')
}

export const SITE_URL = resolveSiteUrl()

/**
 * Backoffice must never be indexed, regardless of SITE_URL.
 */
export function isSearchEngineIndexable(_siteUrl = SITE_URL): boolean {
  return false
}

export const DEFAULT_OG_IMAGE_PATH = '/og-default.jpg'

/** Absolute canonical URL for a site-relative path (e.g. `/city/tehran`). */
export function buildCanonicalUrl(path: string): string {
  return `${SITE_URL}${path.startsWith('/') ? path : `/${path}`}`
}

/**
 * OG image priority per docs/workflows/fa/seo-landing-pages.md § تصویر OG:
 * category `og_image_url` → `cover_image_url` → `banner_image_url` →
 * event poster → site default. Caller passes candidates in that order;
 * the first non-empty one wins.
 */
export function resolveOgImage(...candidates: (string | null | undefined)[]): string {
  const match = candidates.find((candidate) => !!candidate)

  return match ?? buildCanonicalUrl(DEFAULT_OG_IMAGE_PATH)
}

export const DEFAULT_SEO_DESCRIPTION = texts.seo.discoveryDescription