{ config, lib, pkgs, ... }: 

let
  cfg = config.services.emile.r2wars-web;
in with lib; {
  options.services.emile.r2wars-web = {
    enable = mkEnableOption "Enable r2wars-web";

    # ip and port to listen on
    guest = mkOption {
      type = types.str;
      default = "vmnameone";
      example = "vmnameone";
      description = "The name of the vm";
    };
  };

  config = mkIf cfg.enable {
    systemd.services = lib.mapAttrs' (name: guest: lib.nameValuePair "libvirtd-guest-${name}" {
      after = [ "libvirtd.service" ];
      requires = [ "libvirtd.service" ];
      wantedBy = [ "multi-user.target" ];
      serviceConfig = {
        Type = "oneshot";
        RemainAfterExit = "yes";
      };
      script =
        let
          xml = pkgs.writeText "libvirt-guest-${name}.xml"
            ''
              <domain type="kvm">
                <name>${name}</name>
                <uuid>UUID</uuid>
                <os>
                  <type>hvm</type>
                </os>
                <memory unit="GiB">${guest.memory}</memory>
                <devices>
                  <disk type="volume">
                    <source volume="guest-${name}"/>
                    <target dev="vda" bus="virtio"/>
                  </disk>
                  <graphics type="spice" autoport="yes"/>
                  <input type="keyboard" bus="usb"/>
                  <interface type="direct">
                    <source dev="${hostNic}" mode="bridge"/>
                    <mac address="${guest.mac}"/>
                    <model type="virtio"/>
                  </interface>
                </devices>
                <features>
                  <acpi/>
                </features>
              </domain>
            '';
        in
          ''
            uuid="$(${pkgs.libvirt}/bin/virsh domuuid '${name}' || true)"
            ${pkgs.libvirt}/bin/virsh define <(sed "s/UUID/$uuid/" '${xml}')
            ${pkgs.libvirt}/bin/virsh start '${name}'
          '';
      preStop =
        ''
          ${pkgs.libvirt}/bin/virsh shutdown '${name}'
          let "timeout = $(date +%s) + 10"
          while [ "$(${pkgs.libvirt}/bin/virsh list --name | grep --count '^${name}$')" -gt 0 ]; do
            if [ "$(date +%s)" -ge "$timeout" ]; then
              # Meh, we warned it...
              ${pkgs.libvirt}/bin/virsh destroy '${name}'
            else
              # The machine is still running, let's give it some time to shut down
              sleep 0.5
            fi
          done
        '';
    }) guests;
  };
}