import <nixpkgs/nixos/tests/make-test-python.nix> ({ pkgs, lib, ... }:
  let
    deviceIDFilename = "/tmp/syncthing-auto-register-test-device-ids.nix";
    vmConfiguration = pkgs.writeText "vm-configuration.nix" ''
      { pkgs, ... }: {
        imports = [
          ${../.}/lib/test-nixos-rebuild-switch-config.nix
          ${../.}/modules/syncthing-autoregister.nix
        ];
        services.syncthing = {
          enable = true;
          openDefaultPorts = true;
          autoRegister = {
            enable = true;
            path = "${deviceIDFilename}";
          };
        };

        # For verifyDeviceIDSet()
        environment.systemPackages = with pkgs; [ nix ];
      }
    '';

    evaluatedVMConfiguration = import <nixos/nixos/lib/eval-config.nix> {
      system = builtins.currentSystem;
      modules = [ "${vmConfiguration}" ];
    };

    # Also include a syncthing configuration with a device id
    # because using this feature pulls in additional dependencies.
    evaluatedSyncthingDeclarativeConfiguration = import <nixos/nixos/lib/eval-config.nix> {
      system = builtins.currentSystem;
      modules = [
        ../lib/test-nixos-rebuild-switch-config.nix
        {
          services.syncthing = {
            enable = true;
            settings.folders.forDeps.path = "/nope";
          };
        }
      ];
    };

    initialConfiguration = {
        imports = [ "${vmConfiguration}" ];
        virtualisation.memorySize = 2048;
        system.activationScripts.installInitialConfiguration = {
          text = ''
            mkdir -p /etc/nixos
            cp "${vmConfiguration}" /etc/nixos/configuration.nix
          '';
          deps = [ ];
        };
        system.extraDependencies = [
          evaluatedVMConfiguration.config.system.build.toplevel
          evaluatedSyncthingDeclarativeConfiguration.config.system.build.toplevel
        ];
      };

    configurationWithDeviceIDs =
      pkgs.writeText "configuration-with-device-ids.nix" ''
        {
          imports = [
            ${vmConfiguration}
            ${deviceIDFilename}
          ];
        }
      '';

    configurationWithFolder =
      pkgs.writeText "configuration-with-folder.nix" ''
        { config, ... }: {
          imports = [ ${configurationWithDeviceIDs} ];
          services.syncthing.settings.folders.foo = {
            devices = [ "a" "b" ];
            path = "''${config.services.syncthing.dataDir}/foo";
          };
        }
      '';

  in {

    name = "syncthing";

    nodes = {
      a = initialConfiguration;
      b = initialConfiguration;
    };

    testScript = ''
      import os


      def setConfig(machine, config):
          machine.copy_from_host(config, "/etc/nixos/configuration.nix")


      def verifyDeviceIDSet(machine, expectedDevice):
          machine.wait_until_succeeds(
              '(( "$(nix --experimental-features nix-command eval --impure --raw --expr "(import <nixos/nixos> {}).config.services.syncthing.settings.devices.%s.id" | wc -c)" == 63 ))'
              % expectedDevice
          )


      def getDeviceFile(machine):
          machine.copy_from_vm("${deviceIDFilename}")


      def putDeviceFile(machine):
          hostDeviceIDFilename = os.path.join(
              os.environ["out"],
              os.path.basename("${deviceIDFilename}"),
          )
          machine.copy_from_host(
              hostDeviceIDFilename, "${deviceIDFilename}"
          )
          machine.succeed("chown syncthing ${deviceIDFilename}")


      configurationWithDeviceIDs = (
          "${configurationWithDeviceIDs}"
      )
      configurationWithFolder = (
          "${configurationWithFolder}"
      )

      start_all()
      a.wait_for_unit("syncthing-autoregister.service")
      setConfig(a, configurationWithDeviceIDs)
      verifyDeviceIDSet(a, "a")
      getDeviceFile(a)

      b.wait_for_unit("syncthing-autoregister.service")
      putDeviceFile(b)
      setConfig(b, configurationWithDeviceIDs)
      verifyDeviceIDSet(b, "a")
      verifyDeviceIDSet(b, "b")

      getDeviceFile(b)
      putDeviceFile(a)
      setConfig(a, configurationWithFolder)
      setConfig(b, configurationWithFolder)
      a.succeed("nixos-rebuild switch")
      b.succeed("nixos-rebuild switch")
      a.wait_for_file("/var/lib/syncthing/foo")
      b.wait_for_file("/var/lib/syncthing/foo")
      a.succeed("echo a2b > /var/lib/syncthing/foo/a2b")
      b.succeed("echo b2a > /var/lib/syncthing/foo/b2a")
      a.wait_for_file("/var/lib/syncthing/foo/b2a")
      b.wait_for_file("/var/lib/syncthing/foo/a2b")
    '';
  })