export default {
  async fetch(request, env) {
    const url = new URL(request.url);
    const to = url.searchParams.get("to");
    if (!to) return new Response("Missing ?to=", { status: 400 });

    if (request.method === "OPTIONS") {
      return new Response(null, { status: 204, headers: {
        "Access-Control-Allow-Origin": "*",
        "Access-Control-Allow-Methods": "GET,POST,OPTIONS",
        "Access-Control-Allow-Headers": "Content-Type, Authorization, x-api-key, anthropic-version, anthropic-dangerous-direct-browser-access, xi-api-key",
      }});
    }

    const headers = new Headers(request.headers);
    headers.delete("host");

    const resp = await fetch(to, {
      method: request.method,
      headers,
      body: ["GET","HEAD"].includes(request.method) ? undefined : await request.arrayBuffer(),
    });

    const out = new Response(resp.body, resp);
    out.headers.set("Access-Control-Allow-Origin", "*");
    out.headers.set("Access-Control-Expose-Headers", "*");
    return out;
  }
}