import fs from "node:fs";
import path from "node:path";
import { NextResponse } from "next/server";
import { WEBSITE_DOMAIN } from "@/lib/meshkee";

// Published for the Meshkee business dashboard's "Refresh" sitemap button —
// see AI_PROMPT.md ("What the website must publish"). Meshkee's own nginx
// proxy serves the actual /sitemap.xml (and the CMS-driven child sitemaps
// like /sitemap-blogs.xml) from the API; this route only lists this app's
// *static* public pages so the dashboard can fold them into the sitemap
// index. Do not add app/sitemap.ts / app/robots.ts — those paths are owned
// by the Meshkee proxy once this site is live on a Meshkee-managed domain.

export const dynamic = "force-static";

// Route segments that never map to a crawlable public page: dynamic detail
// pages (CMS-managed — Meshkee generates their own sitemap entries), and
// this "meshkee/*" integration namespace itself.
const EXCLUDE_SEGMENT = (segment) =>
  segment.startsWith("[") || segment === "meshkee" || segment.startsWith("_");

// Per-path SEO weight. Anything not listed falls back to a sane default.
const PAGE_META = {
  "/": { changefreq: "daily", priority: 1.0 },
  "/services": { changefreq: "weekly", priority: 0.8 },
  "/about-us": { changefreq: "monthly", priority: 0.6 },
  "/blog": { changefreq: "daily", priority: 0.7 },
  "/contact-us": { changefreq: "monthly", priority: 0.5 },
  "/virtual-tour": { changefreq: "yearly", priority: 0.4 },
};

/** Scan app/ for `page.js` files and turn each into a public URL path. */
function scanStaticPages(dir, baseSegments = []) {
  const pages = [];
  let entries;
  try {
    entries = fs.readdirSync(dir, { withFileTypes: true });
  } catch {
    return pages;
  }

  const hasPage = entries.some(
    (e) => e.isFile() && /^page\.(js|jsx|ts|tsx)$/.test(e.name)
  );
  if (hasPage && !baseSegments.some(EXCLUDE_SEGMENT)) {
    const urlPath = "/" + baseSegments.join("/");
    pages.push(urlPath === "/" ? "/" : urlPath.replace(/\/$/, ""));
  }

  for (const entry of entries) {
    if (!entry.isDirectory()) continue;
    // route groups "(name)" don't appear in the URL
    const isGroup = entry.name.startsWith("(") && entry.name.endsWith(")");
    const nextSegments = isGroup
      ? baseSegments
      : [...baseSegments, entry.name];
    if (EXCLUDE_SEGMENT(entry.name)) continue;
    pages.push(...scanStaticPages(path.join(dir, entry.name), nextSegments));
  }

  return pages;
}

export async function GET() {
  const appDir = path.join(process.cwd(), "app");
  const paths = scanStaticPages(appDir).sort(
    (a, b) => a.split("/").length - b.split("/").length || a.localeCompare(b)
  );

  const staticPages = paths.map((p) => ({
    path: p,
    ...(PAGE_META[p] || { changefreq: "monthly", priority: 0.5 }),
  }));

  return NextResponse.json({
    baseUrl: `https://${WEBSITE_DOMAIN}`,
    staticPages,
  });
}