export default {
  async fetch(request) {
    const url = new URL(request.url);

    // Healthcheck
    if (url.pathname === "/health") {
      return new Response("OK - Worker running", { status: 200 });
    }

    const ORIGIN_HOST = "line.sir24.biz";
    const ORIGIN_PORT = "8080";
    const ORIGIN_PROTO = "http";

    // Target origin URL
    const target = new URL(request.url);
    target.protocol = ORIGIN_PROTO + ":";
    target.hostname = ORIGIN_HOST;
    target.port = ORIGIN_PORT;

    // Clone headers and force Host
    const headers = new Headers(request.headers);
    headers.set("Host", ORIGIN_HOST);
    headers.set("X-Forwarded-Host", ORIGIN_HOST);

    // Forward real client IP (origin must read these)
    const realIp = request.headers.get("CF-Connecting-IP");
    if (realIp) {
      const prior = request.headers.get("X-Forwarded-For");
      headers.set("X-Forwarded-For", prior ? `${prior}, ${realIp}` : realIp);
    }

    // Remove headers that can cause issues
    headers.delete("Content-Length");
    headers.delete("Accept-Encoding"); // évite certains soucis gzip/brotli

    const init = {
      method: request.method,
      headers,
      redirect: "manual",
    };

    if (request.method !== "GET" && request.method !== "HEAD") {
      init.body = await request.arrayBuffer();
    }

    const resp = await fetch(target.toString(), init);

    // Copy response headers so we can rewrite Location if needed
    const outHeaders = new Headers(resp.headers);

    // Rewrite redirects to keep your domain in the client URL
    const loc = outHeaders.get("Location");
    if (loc) {
      try {
        const l = new URL(loc, url); // handle relative too
        // if origin redirects to origin host, rewrite to your public host
        if (l.hostname === ORIGIN_HOST && (l.port === ORIGIN_PORT || l.port === "")) {
          l.protocol = url.protocol;
          l.host = url.host; // includes your hostname + port if any
          outHeaders.set("Location", l.toString());
        }
      } catch (_) {
        // ignore invalid Location
      }
    }

    return new Response(resp.body, {
      status: resp.status,
      headers: outHeaders,
    });
  },
};