export interface StaticAssets {
  files: Record<string, Blob>;
  indexHtml: Blob;
}

const CONTENT_TYPES: Record<string, string> = {
  ".css": "text/css; charset=utf-8",
  ".html": "text/html; charset=utf-8",
  ".js": "text/javascript; charset=utf-8",
  ".json": "application/json; charset=utf-8",
  ".mjs": "text/javascript; charset=utf-8",
  ".png": "image/png",
  ".svg": "image/svg+xml",
  ".woff": "font/woff",
  ".woff2": "font/woff2",
};

export function contentTypeFor(path: string): string {
  const dot = path.lastIndexOf(".");
  if (dot === -1) return "application/octet-stream";
  const ext = path.slice(dot);
  return CONTENT_TYPES[ext] ?? "application/octet-stream";
}

export function hasFileExtension(path: string): boolean {
  const lastSlash = path.lastIndexOf("/");
  const segment = lastSlash === -1 ? path : path.slice(lastSlash + 1);
  return segment.includes(".");
}

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

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

  const file = assets.files[pathname];
  if (file) {
    return new Response(file, {
      headers: {
        "Cache-Control": "public, max-age=31536000, immutable",
        "Content-Type": contentTypeFor(pathname),
      },
    });
  }

  if (hasFileExtension(pathname)) {
    return new Response("Not found", { status: 404 });
  }

  return htmlResponse(assets.indexHtml);
}