import { isMetadataRoute, isMetadataRouteFile } from "./is-metadata-route";
import path from "../../shared/lib/isomorphic/path";
import { djb2Hash } from "../../shared/lib/hash";

/*
 * If there's special convention like (...) or @ in the page path,
 * Give it a unique hash suffix to avoid conflicts
 *
 * e.g.
 * /app/open-graph.tsx -> /open-graph/route
 * /app/(post)/open-graph.tsx -> /open-graph/route-[0-9a-z]{6}
 */
export function getMetadataRouteSuffix(page: string) {
  let suffix = "";

  if ((page.includes("(") && page.includes(")")) || page.includes("@")) {
    suffix = djb2Hash(page).toString(36).slice(0, 6);
  }
  return suffix;
}

/**
 * Map metadata page key to the corresponding route
 *
 * static file page key:    /app/robots.txt -> /robots.xml -> /robots.txt/route
 * dynamic route page key:  /app/robots.tsx -> /robots -> /robots.txt/route
 *
 * @param page
 * @returns
 */
export function normalizeMetadataRoute(page: string) {
  let route = page;
  if (isMetadataRoute(page)) {
    // Remove the file extension, e.g. /route-path/robots.txt -> /route-path
    const pathnamePrefix = page.slice(0, -(path.basename(page).length + 1));
    const suffix = getMetadataRouteSuffix(pathnamePrefix);

    if (route === "/sitemap") {
      route += ".xml";
    }
    if (route === "/robots") {
      route += ".txt";
    }
    if (route === "/manifest") {
      route += ".webmanifest";
    }
    // Support both /<metadata-route.ext> and custom routes /<metadata-route>/route.ts.
    // If it's a metadata file route, we need to append /[id]/route to the page.
    if (!route.endsWith("/route")) {
      const isStaticMetadataFile = isMetadataRouteFile(route, [], true);
      const { dir, name: baseName, ext } = path.parse(route);

      const isSingleRoute = page.startsWith("/sitemap") ||
        page.startsWith("/robots") ||
        page.startsWith("/manifest") ||
        isStaticMetadataFile;

      route = path.join(
        dir,
        `${baseName}${suffix ? `-${suffix}` : ""}${ext}`,
        isSingleRoute ? "" : "[[...__metadata_id__]]",
        "route",
      );
    }
  }
  return route;
}