import { readdir, writeFile } from "node:fs/promises";
import { dirname, join, relative, resolve } from "node:path";
import { fileURLToPath } from "node:url";

const root = resolve(dirname(fileURLToPath(import.meta.url)), "..");
const appDirectory = join(root, "app");
const outputFile = join(root, "data", "generated-sitemap-pages.ts");
const pageFilePattern = /^page\.(?:js|jsx|ts|tsx)$/;
const excludedSegments = new Set([
  "admin",
  "api",
  "auth",
  "cart",
  "checkout",
  "meshkee",
]);

const routeSettings = {
  "/": { changefreq: "daily", priority: 1 },
  "/products": { changefreq: "daily", priority: 0.9 },
  "/blog": { changefreq: "weekly", priority: 0.8 },
  "/features": { changefreq: "monthly", priority: 0.7 },
  "/about": { changefreq: "monthly", priority: 0.6 },
  "/contact": { changefreq: "monthly", priority: 0.5 },
};

function toRoute(directory) {
  const route = relative(appDirectory, directory)
    .split("/")
    .filter((segment) => segment && !segment.startsWith("("))
    .join("/");
  return route ? `/${route}` : "/";
}

function isPublicStaticRoute(route) {
  const segments = route.split("/").filter(Boolean);
  return (
    !segments.some(
      (segment) =>
        segment.startsWith("[") ||
        segment.startsWith("_") ||
        excludedSegments.has(segment),
    )
  );
}

async function collectPages(directory) {
  const entries = await readdir(directory, { withFileTypes: true });
  const route = toRoute(directory);
  const pages = [];

  if (
    isPublicStaticRoute(route) &&
    entries.some((entry) => entry.isFile() && pageFilePattern.test(entry.name))
  ) {
    pages.push(route);
  }

  for (const entry of entries) {
    if (!entry.isDirectory()) continue;
    const childRoute = toRoute(join(directory, entry.name));
    if (!isPublicStaticRoute(childRoute)) continue;
    pages.push(...(await collectPages(join(directory, entry.name))));
  }

  return pages;
}

const routes = [...new Set(await collectPages(appDirectory))].sort((a, b) => {
  if (a === "/") return -1;
  if (b === "/") return 1;
  return a.localeCompare(b, "en");
});

const pages = routes.map((path) => ({
  path,
  ...(routeSettings[path] ?? { changefreq: "monthly", priority: 0.5 }),
}));

const source = `// Generated by scripts/generate-sitemap-config.mjs. Do not edit manually.
export const generatedStaticPages = ${JSON.stringify(pages, null, 2)} as const;
`;

await writeFile(outputFile, source, "utf8");
console.log(`Generated ${pages.length} public sitemap routes in ${relative(root, outputFile)}.`);