import { readdirSync } from "node:fs";
import { join } from "node:path";

export const dynamic = "force-static";
export const runtime = "nodejs";

type StaticPage = {
  path: string;
  changefreq: "daily" | "weekly" | "monthly";
  priority: number;
};

const EXCLUDED_SEGMENTS = new Set([
  "account",
  "admin",
  "api",
  "auth",
  "cart",
  "checkout",
  "login",
  "meshkee",
  "register",
]);

function collectStaticPagePaths(
  directory: string,
  routeSegments: string[] = [],
): string[] {
  const entries = readdirSync(directory, { withFileTypes: true });
  const paths: string[] = [];

  if (entries.some((entry) => entry.isFile() && /^page\.[jt]sx?$/.test(entry.name))) {
    const path = routeSegments.length ? `/${routeSegments.join("/")}` : "/";
    paths.push(path);
  }

  for (const entry of entries) {
    if (!entry.isDirectory()) continue;

    const isRouteGroup = entry.name.startsWith("(") && entry.name.endsWith(")");
    const isPrivateFolder = entry.name.startsWith("_");
    const isParallelRoute = entry.name.startsWith("@");
    const isDynamicRoute = entry.name.includes("[");

    if (
      isPrivateFolder ||
      isParallelRoute ||
      isDynamicRoute ||
      EXCLUDED_SEGMENTS.has(entry.name)
    ) {
      continue;
    }

    paths.push(
      ...collectStaticPagePaths(
        join(directory, entry.name),
        isRouteGroup ? routeSegments : [...routeSegments, entry.name],
      ),
    );
  }

  return paths;
}

function toStaticPage(path: string): StaticPage {
  if (path === "/") {
    return { path, changefreq: "daily", priority: 1 };
  }

  if (path === "/about-us") {
    return { path, changefreq: "monthly", priority: 0.6 };
  }

  if (path === "/contact-us") {
    return { path, changefreq: "monthly", priority: 0.5 };
  }

  return { path, changefreq: "weekly", priority: 0.5 };
}

export function GET() {
  const baseUrl = (
    process.env.NEXT_PUBLIC_SITE_URL ||
    process.env.SITE_URL ||
    "https://samanandish.com"
  ).replace(/\/$/, "");

  const staticPages = collectStaticPagePaths(join(process.cwd(), "app"))
    .sort((first, second) => {
      if (first === "/") return -1;
      if (second === "/") return 1;
      return first.localeCompare(second);
    })
    .map(toStaticPage);

  return Response.json(
    { baseUrl, staticPages },
    {
      headers: {
        "Cache-Control": "public, max-age=300, stale-while-revalidate=3600",
      },
    },
  );
}