{ config, pkgs, inputs, ... }:

{
  boot = {
    kernel.sysctl."net.ipv6.conf.all.forwarding" = true;
  };

  # Enable LTE drivers
  hardware.usb-modeswitch.enable = true;

  ##################
  # NETWORK CONFIG #
  ##################

  # eno1      -> VLAN100 -> Internet
  # eno2      -> LAN
  # eno3      -> Pas utilisé
  # eno4      -> Pas utilisé
  # enp0s21u1 -> Clé 4G Bouygues
  # wg0       -> Tunnel Wireguard ARN

  networking = {
    hostName = "loutreos"; # Define your hostname.
    hostId = "7e66e347";

    useNetworkd = true;
    useDHCP = false;

    nameservers = [
      "1.1.1.1"
      "1.0.0.1"
    ];

    vlans = {
      bouygues = {
        id = 100;
        interface = "eno1";
      };
    };

    interfaces = {
      bouygues = {
        # Adresse MAC BBox ? https://lafibre.info/remplacer-bbox/informations-de-connexion-ftth/msg598303/#msg598303
        macAddress = "E8:AD:A6:21:73:68";
        useDHCP = true;
      };
      eno2 = {
        ipv4.addresses = [
          { address = "10.30.0.1"; prefixLength = 16; }
        ];
      };
      enp0s21u1.useDHCP = true;
    };

    # NAT bouygues <-> eno2
    nat = {
      enable = true;
      externalInterface = "bouygues";
      internalIPs = [ "10.30.0.0/16" ];
      internalInterfaces = [ "eno2" ];
      forwardPorts = [
        { destination = "10.30.0.1:22"; proto = "tcp"; sourcePort = 8443;}
        { destination = "10.30.135.35:25565"; proto = "tcp"; sourcePort = 25565; loopbackIPs=[ "195.36.180.44" ];}
      ];
    };

    firewall = {
      enable = true;
      allowedTCPPorts = [ 80 443 ];
      allowedUDPPorts = [ ];

      # Open ports on local netwok only
      interfaces.eno2 = {
        allowedTCPPorts = [
          111 2049 4000 4001 4002 # NFS
          3483 9000 9090 # Slimserver
          1935 # RTMP
        ];
        allowedUDPPorts = [
          111 2049 4000 4001 4002 # NFS
          3483 # Slimserver
          67 # DHCP
        ];
      };

      extraCommands = ''
        # Forward all IPv6 traffic from local network and reject incoming traffic
        ip6tables -w -D FORWARD -j loutreos-forward 2>/dev/null || true
        ip6tables -w -F loutreos-forward 2>/dev/null || true
        ip6tables -w -X loutreos-forward 2>/dev/null || true
        ip6tables -w -N loutreos-forward
        ip6tables -A loutreos-forward -m state --state RELATED,ESTABLISHED -j ACCEPT
        ip6tables -A loutreos-forward -j ACCEPT -i eno2
        ip6tables -A loutreos-forward -j nixos-fw-log-refuse
        ip6tables -w -A FORWARD -j loutreos-forward

        # Redirect local network request from server external IP to internal IP
        # Make the server available even without internet access
        iptables -t nat -D PREROUTING -s 10.30.0.0/16 -d 176.180.172.105 -j DNAT --to 10.30.0.1 || true
        iptables -t nat -A PREROUTING -s 10.30.0.0/16 -d 176.180.172.105 -j DNAT --to 10.30.0.1
      '';
      # remove refs to nixos-fw-log-refuse before restarting firewall
      # prevents "ressource busy" errors
      extraStopCommands = ''
        ip6tables -D loutreos-forward -j nixos-fw-log-refuse 2>/dev/null || true
      '';
    };
  };

  #################
  # ROUTING RULES #
  #################

  # 0:      from all lookup local
  # 50:     from all ipproto tcp dport 25 lookup vpn
  # 100:    from all lookup fiber
  # 200:    from all lookup lte
  # 32766:  from all lookup main
  # 32767:  from all lookup default

  systemd.network = {
    enable = true;

    config = {
      routeTables = {
        fiber = 1;
        lte = 2;
        vpn = 3;
      };
      addRouteTablesToIPRoute2 = true;
    };

    # Wireguard ARN device configuation
    netdevs = {
      "10-wg0" = {
        netdevConfig = {
          Kind = "wireguard";
          Name = "wg0";
          MTUBytes = "1450";
        };
        wireguardConfig = {
          PrivateKeyFile = "/run/keys/wireguard-privkey";
          RouteTable = "vpn";
        };
        wireguardPeers = [
          {
            wireguardPeerConfig = {
              Endpoint = "89.234.141.83:8095";
              PublicKey = "t3+JkBfXI1uw8fa9P6JfxXJfTPm9cOHcgIN215UHg2g=";
              PresharedKeyFile = "/run/keys/wireguard-psk.key";
              AllowedIPs = ["0.0.0.0/0" "::/0"];
              PersistentKeepalive = 15;
            };
          }
        ];
      };
    };

    networks = {
      #########
      # FIBER #
      #########

      # Set DHCP client magic settings for Bouygues
      # Put routes in fiber table
      "40-bouygues" = {
        dhcpV4Config.RouteTable = "fiber";
        dhcpV6Config = {
          DUIDRawData = "00:03:00:01:E8:AD:A6:21:73:68";
          WithoutRA = "solicit";
        };
        ipv6AcceptRAConfig = {
          DHCPv6Client = true;
          RouteTable = "fiber";
        };
        networkConfig = {
          KeepConfiguration = "dhcp-on-stop";
          IPv6AcceptRA = true;
          DHCPPrefixDelegation = true;
        };
        # Static attribution of first IPv6 subnet
        dhcpPrefixDelegationConfig.SubnetId = "0";

        # Route everything to fiber link with a priority of 100
        routingPolicyRules = [
          {
            routingPolicyRuleConfig = {
              Table = "fiber";
              Priority = "100";
              Family = "both";
            };
          }
        ];
      };

      # Don't check VLAN physical interface as it is not directly used
      "40-eno1".linkConfig.RequiredForOnline = "no";

      #######
      # LTE #
      #######

      # Put routes in lte table
      "40-enp0s21u1" = {
        dhcpV4Config.RouteTable = "lte";

        # Route all to lte link with a priority of 200
        routingPolicyRules = [
          {
            routingPolicyRuleConfig = {
              Table = "lte";
              Priority = "200";
              Family = "both";
            };
          }
        ];
      };

      #######
      # VPN #
      #######

      # Wireguard ARN network configuation
      "10-wg0" = {
        matchConfig.Name = "wg0";
        address = [
          "89.234.141.196/32"
          "2a00:5881:8119:400::1/128"
        ];
        routingPolicyRules = [
          # Route outgoing emails to VPN table
          {
            routingPolicyRuleConfig = {
              DestinationPort = "25";
              Table = "vpn";
              Priority = "50";
              Family = "both";
            };
          }
        ];
      };

      #######
      # LAN #
      #######

      # LAN DHCP server config
      "40-eno2" = {
        networkConfig = {
          IPv6SendRA = true;
          DHCPPrefixDelegation = true;
          DHCPServer = true;
        };
        dhcpServerConfig = {
          EmitRouter = true;
          EmitDNS = true;
          DNS = [
            "1.1.1.1"
            "1.0.0.1"
          ];
        };
        dhcpServerStaticLeases = [
          # IPMI
          {
            dhcpServerStaticLeaseConfig = {
              Address = "10.30.1.1";
              MACAddress = "ac:1f:6b:4b:01:15";
            };
          }
          # paul-fixe
          {
            dhcpServerStaticLeaseConfig = {
              Address = "10.30.50.1";
              MACAddress = "b4:2e:99:ed:24:26";
            };
          }
          # salonled
          {
            dhcpServerStaticLeaseConfig = {
              Address = "10.30.40.1";
              MACAddress = "e0:98:06:85:e9:ce";
            };
          }
          # miroir-bleu
          {
            dhcpServerStaticLeaseConfig = {
              Address = "10.30.40.2";
              MACAddress = "e0:98:06:86:38:fc";
            };
          }
          # miroir-orange
          {
            dhcpServerStaticLeaseConfig = {
              Address = "10.30.40.3";
              MACAddress = "50:02:91:78:be:be";
            };
          }
        ];
        ipv6SendRAConfig = {
          EmitDNS = true;
          DNS = [
            "2606:4700:4700::1111"
            "2606:4700:4700::1001"
          ];
        };
      };
    };
  };
}