const FIRST_PARTY_PERSONA_PATH = /^personas\/p[4-7]\/[a-z0-9._/-]+$/i;

function notFound() {
  return new Response("Live2D demo assets are not part of this deployment.", {
    status: 404,
    headers: {
      "cache-control": "no-store",
      "content-type": "text/plain; charset=utf-8",
      "x-robots-tag": "noindex",
    },
  });
}

function normalizePathParam(value) {
  if (Array.isArray(value)) return value.join("/");
  return String(value ?? "");
}

export async function onRequest(context) {
  const requestedPath = normalizePathParam(context.params?.path)
    .replace(/^\/+/, "")
    .replace(/\\/g, "/");

  if (requestedPath.split("/").some((segment) => segment === "." || segment === "..")) {
    return notFound();
  }

  if (!FIRST_PARTY_PERSONA_PATH.test(requestedPath)) {
    return notFound();
  }

  const assetResponse = context.env?.ASSETS
    ? await context.env.ASSETS.fetch(context.request)
    : null;

  if (!assetResponse || assetResponse.status === 404) {
    return notFound();
  }

  const headers = new Headers(assetResponse.headers);
  headers.set("cache-control", "public, max-age=300");
  headers.set("x-robots-tag", "noindex");
  return new Response(assetResponse.body, {
    status: assetResponse.status,
    headers,
  });
}