import type { Metadata } from "next"

export const SITE_NAME = "Property Management Network"

// The generated Open Graph card (app/opengraph-image.tsx), served at this path.
// Declared explicitly because a page that sets its own `openGraph` object
// replaces the inherited one — including the image Next.js attaches from the
// file convention — which silently leaves that page with no share image.
const OG_IMAGE = "/opengraph-image"

type PageSeo = {
  /**
   * Page title. Rendered through the root layout's "%s | Property Management
   * Network" template unless `absoluteTitle` is set.
   */
  title: string
  /** Render `title` verbatim, without the site-name suffix. */
  absoluteTitle?: boolean
  description: string
  /** Canonical path, root-relative and without a trailing slash, e.g. "/terms". */
  path: string
  /**
   * Headline used for the Open Graph / Twitter card when the share copy should
   * differ from the page title. Defaults to the resolved page title.
   */
  socialTitle?: string
  /** Set false for pages that must stay out of the index. */
  index?: boolean
}

/**
 * Builds a complete, self-consistent metadata block for a public page.
 *
 * Every public page must go through this helper so that canonical, og:url,
 * og:title, og:image and the Twitter card always agree with each other and with
 * the page's real URL. Setting these ad hoc per page is what previously left the
 * landing page with no share image and every legal page pointing og:url at "/".
 */
export function pageMetadata({
  title,
  absoluteTitle = false,
  description,
  path,
  socialTitle,
  index = true,
}: PageSeo): Metadata {
  const fullTitle = absoluteTitle ? title : `${title} | ${SITE_NAME}`
  const social = socialTitle ?? fullTitle

  return {
    title: absoluteTitle ? { absolute: title } : title,
    description,
    alternates: { canonical: path },
    openGraph: {
      title: social,
      description,
      url: path,
      siteName: SITE_NAME,
      locale: "en_US",
      type: "website",
      images: [OG_IMAGE],
    },
    twitter: {
      card: "summary_large_image",
      title: social,
      description,
      images: [OG_IMAGE],
    },
    ...(index ? {} : { robots: { index: false, follow: true } }),
  }
}