vcl 4.1;

# https://github.com/varnish/toolbox/tree/master/vcls/hit-miss
include "hit-miss.vcl";

# import vmod_dynamic for better backend name resolution
import dynamic;
import std;

backend default {
  .host = "rstat-dashboard";
  .port = "5000";
}

acl purge {
  "localhost";
  "nginx";
  "127.0.0.1";
}

sub vcl_recv {
  if (req.url ~ "/purge-cache") {
    if (!client.ip ~ purge) {
      return(synth(403, "Not allowed."));
    }
    ban("req.http.host == rstat.net");
    return(synth(200, "Cache cleared"));
  }
  
  # Cache static files
  if (req.url ~ "\.(css|js|avif|webp|png|jpe?g|gif|ico|svg|woff2?|eot|ttf|otf|json|csv|pdf|mp4|webm|ogg|mp3|wav|flac)$") {
    unset req.http.Cookie;
    return(hash);
  }
  
  # Remove all cookies for other requests
  unset req.http.Cookie;
  return(hash);
}

sub vcl_backend_response {
  # Cache static files and other content in Varnish for 1 year
  set beresp.ttl = 1m;
  # Enable stale content serving
  set beresp.grace = 24h;
  # Preserve the origin's Cache-Control header for client-side caching
  if (beresp.http.Cache-Control) {
    set beresp.http.X-Orig-Cache-Control = beresp.http.Cache-Control;
  }
}

sub vcl_deliver {
  # Restore the origin's Cache-Control header for the browser
  if (resp.http.X-Orig-Cache-Control) {
    set resp.http.Cache-Control = resp.http.X-Orig-Cache-Control;
    unset resp.http.X-Orig-Cache-Control;
  } else {
    # If no Cache-Control was set by the origin, we'll set a default
    set resp.http.Cache-Control = "no-cache, must-revalidate";
  }
}