export default {
  async fetch(request, env) {
    const url = new URL(request.url);
    let pathname = url.pathname.replace(/\/{2,}/g, "/");

    // Serve admin UI at root /
    if (pathname === "/") {
      return serveFromKV(env, "admin", "index.html");
    }

    // Normalize /site -> /site/
    if (!pathname.endsWith("/") && pathname.split("/").length === 2) {
      const redirectUrl = new URL(url);
      redirectUrl.pathname = pathname + "/";
      return Response.redirect(redirectUrl.toString(), 301);
    }

    // Split path
    const parts = pathname.replace(/^\/+/, "").split("/");

    if (!parts[0]) {
      return new Response("Not Found", { status: 404 });
    }

    const site = parts[0];
    const filePath =
      parts.length === 1 || parts[1] === ""
        ? "index.html"
        : parts.slice(1).join("/");

    return serveFromKV(env, site, filePath);
  },
};

async function serveFromKV(env, site, filePath) {
  const key = `site:${site}:${filePath}`;

  const content = await env.PAGES_KV.get(key, {
    type: "arrayBuffer",
  });

  if (!content) {
    return new Response("Not Found", { status: 404 });
  }

  return new Response(content, {
    headers: {
      "Content-Type": contentType(filePath),
      "Cache-Control": "public, max-age=300",
    },
  });
}

function contentType(path) {
  if (path.endsWith(".html")) return "text/html; charset=utf-8";
  if (path.endsWith(".css")) return "text/css; charset=utf-8";
  if (path.endsWith(".js")) return "application/javascript; charset=utf-8";
  if (path.endsWith(".json")) return "application/json; charset=utf-8";
  if (path.endsWith(".png")) return "image/png";
  if (path.endsWith(".jpg") || path.endsWith(".jpeg")) return "image/jpeg";
  if (path.endsWith(".svg")) return "image/svg+xml";
  if (path.endsWith(".ico")) return "image/x-icon";
  if (path.endsWith(".woff")) return "font/woff";
  if (path.endsWith(".woff2")) return "font/woff2";
  return "application/octet-stream";
}