import type { MetadataRoute } from "next";

const SITE_URL =
  process.env.NEXT_PUBLIC_SITE_URL || "https://prabhupadasays.org";

/**
 * robots.txt (generated).
 *
 * Open the whole site to crawlers — search engines AND AI/LLM crawlers
 * (GPTBot, ClaudeBot, PerplexityBot, Google-Extended, etc. all honour the
 * `*` rule, and we deliberately don't block them so the corpus is
 * discoverable). Only private / non-content surfaces are disallowed:
 *
 *   • /api/           — JSON endpoints, never a destination page
 *   • /settings       — auth-only account settings
 *   • /notifications  — auth-only
 *   • /verify-email   — transactional
 *   • /chat           — interactive tool, not indexable content
 *   • /u/me, /u/me/*  — the signed-in user's own private library
 *                       ($ anchors the bare path so public handles like
 *                       /u/meera aren't caught by the prefix)
 *
 * Public content (books, verses, prose, letters, transcriptions, essays,
 * disciples, magazines, journals, glossary, public profiles, collections)
 * stays crawlable and is enumerated in the sitemap index.
 */
export default function robots(): MetadataRoute.Robots {
  return {
    rules: {
      userAgent: "*",
      allow: "/",
      disallow: [
        "/api/",
        "/settings",
        "/notifications",
        "/verify-email",
        "/chat",
        "/u/me$",
        "/u/me/",
      ],
    },
    sitemap: `${SITE_URL}/sitemap.xml`,
    host: SITE_URL,
  };
}