# This module is necessary for hosts that are serving through Cloudflare.

{ config, lib, ... }:

let

  cloudflareIpRanges = [

    # Cloudflare IPv4: https://www.cloudflare.com/ips-v4
    "173.245.48.0/20"
    "103.21.244.0/22"
    "103.22.200.0/22"
    "103.31.4.0/22"
    "141.101.64.0/18"
    "108.162.192.0/18"
    "190.93.240.0/20"
    "188.114.96.0/20"
    "197.234.240.0/22"
    "198.41.128.0/17"
    "162.158.0.0/15"
    "104.16.0.0/13"
    "104.24.0.0/14"
    "172.64.0.0/13"
    "131.0.72.0/22"

    # Cloudflare IPv6: https://www.cloudflare.com/ips-v6
    "2400:cb00::/32"
    "2606:4700::/32"
    "2803:f800::/32"
    "2405:b500::/32"
    "2405:8100::/32"
    "2a06:98c0::/29"
    "2c0f:f248::/32"

  ];

in {

  options.cloudflare.enable = lib.mkEnableOption "Use Cloudflare.";

  config = lib.mkIf config.cloudflare.enable {

    # Forces Caddy to error if coming from a non-Cloudflare IP
    caddy.blocks = [{
      match = [{ not = [{ remote_ip.ranges = cloudflareIpRanges; }]; }];
      handle = [{
        handler = "static_response";
        abort = true;
      }];
    }];

    # Allows Nextcloud to trust Cloudflare IPs
    services.nextcloud.config.trustedProxies = cloudflareIpRanges;

  };
}