DiAL/src/server/static.ts

import type { RuntimeMode } from "../shared/api";
import type { StaticAssets } from "./app";

import { createHeaders } from "./helpers";

export function contentTypeFor(pathname: string): string {
  if (pathname.endsWith(".js") || pathname.endsWith(".mjs")) return "text/javascript; charset=utf-8";
  if (pathname.endsWith(".css")) return "text/css; charset=utf-8";
  if (pathname.endsWith(".svg")) return "image/svg+xml";
  if (pathname.endsWith(".json")) return "application/json; charset=utf-8";
  if (pathname.endsWith(".png")) return "image/png";
  if (pathname.endsWith(".jpg") || pathname.endsWith(".jpeg")) return "image/jpeg";
  if (pathname.endsWith(".ico")) return "image/x-icon";

  return "application/octet-stream";
}

export function hasFileExtension(pathname: string): boolean {
  return /\/[^/]+\.[^/]+$/.test(pathname);
}

export function htmlResponse(indexHtml: Blob, mode: RuntimeMode): Response {
  return new Response(indexHtml, {
    headers: createHeaders(mode, {
      "Cache-Control": "no-cache",
      "Content-Type": "text/html; charset=utf-8",
    }),
  });
}

export function serveStaticAsset(pathname: string, staticAssets: StaticAssets, mode: RuntimeMode): Response {
  if (pathname === "/") {
    return htmlResponse(staticAssets.indexHtml, mode);
  }

  const asset = staticAssets.files[pathname];

  if (asset) {
    return new Response(asset, {
      headers: createHeaders(mode, {
        "Cache-Control": "public, max-age=31536000, immutable",
        "Content-Type": contentTypeFor(pathname),
      }),
    });
  }

  if (pathname.startsWith("/assets/") || hasFileExtension(pathname)) {
    return new Response("Not Found", {
      headers: createHeaders(mode, { "Content-Type": "text/plain; charset=utf-8" }),
      status: 404,
    });
  }

  return htmlResponse(staticAssets.indexHtml, mode);
}