import fs from "fs";
import path from "path";

export type RouteNode = {
  name: string;
  path: string;
  children?: RouteNode[];
};

export function getRouteTree(): RouteNode[] {
  const appDir = path.join(process.cwd(), "app");

  function walk(currentDir: string, baseRoute = ""): RouteNode[] {
    const entries = fs.readdirSync(currentDir, { withFileTypes: true });

    return entries
      .filter((e) => {
        if (!e.isDirectory()) return false;

        // EXCLUDE folders that should not be routes
        if (e.name.startsWith("_")) return false;
        if (e.name.startsWith("(")) return false;
        if (e.name.startsWith("[")) return false; // hide [...path]

        // Only include if folder HAS a page.tsx OR contains nested route pages
        const folderPath = path.join(currentDir, e.name);
        const hasPage = fs.existsSync(path.join(folderPath, "page.tsx"));

        const hasNestedPages = fs
          .readdirSync(folderPath)
          .some((child) => {
            const full = path.join(folderPath, child);
            return (
              fs.lstatSync(full).isDirectory() &&
              fs.existsSync(path.join(full, "page.tsx"))
            );
          });

        return hasPage || hasNestedPages;
      })
      .map((folder) => {
        const folderPath = path.join(currentDir, folder.name);
        const routePath = `${baseRoute}/${folder.name}`;

        const children = walk(folderPath, routePath);

        return {
          name: folder.name,
          path: routePath,
          children,
        };
      });
  }

  return walk(appDir, "");
}