{ pkgs, ... }:

{
  name = "nixos-basics";
  meta.maintainers = [ pkgs.lib.maintainers.rycee ];

  nodes.machine = { ... }: {
    imports = [ ../../../nixos ]; # Import the HM NixOS module.

    virtualisation.memorySize = 2048;

    users.users.alice = {
      isNormalUser = true;
      description = "Alice Foobar";
      password = "foobar";
      uid = 1000;
    };

    home-manager.users.alice = { ... }: {
      home.stateVersion = "24.05";
      home.file.test.text = "testfile";
      # Enable a light-weight systemd service.
      services.pueue.enable = true;
      # We focus on sd-switch since that hopefully will become the default in
      # the future.
      systemd.user.startServices = "sd-switch";
    };
  };

  testScript = ''
    def login_as_alice():
      machine.wait_until_tty_matches("1", "login: ")
      machine.send_chars("alice\n")
      machine.wait_until_tty_matches("1", "Password: ")
      machine.send_chars("foobar\n")
      machine.wait_until_tty_matches("1", "alice\\@machine")

    def logout_alice():
      machine.send_chars("exit\n")

    def alice_cmd(cmd):
      return f"su -l alice --shell /bin/sh -c $'export XDG_RUNTIME_DIR=/run/user/$UID ; {cmd}'"

    def succeed_as_alice(cmd):
      return machine.succeed(alice_cmd(cmd))

    def fail_as_alice(cmd):
      return machine.fail(alice_cmd(cmd))

    start_all()

    machine.wait_for_console_text("Finished Home Manager environment for alice.")

    with subtest("Home Manager file"):
      # The file should be linked with the expected content.
      path = "/home/alice/test"
      machine.succeed(f"test -L {path}")
      actual = machine.succeed(f"cat {path}")
      expected = "testfile"
      assert actual == expected, f"expected {path} to contain {expected}, but got {actual}"

    with subtest("Pueue service"):
      login_as_alice()

      actual = succeed_as_alice("pueue status")
      expected = "running"
      assert expected in actual, f"expected pueue status to contain {expected}, but got {actual}"

      # Shut down pueue, then run the activation again. Afterwards, the service
      # should be running.
      machine.succeed("systemctl --user -M alice@.host stop pueued.service")

      fail_as_alice("pueue status")

      machine.systemctl("restart home-manager-alice.service")
      machine.wait_for_console_text("Finished Home Manager environment for alice.")

      actual = succeed_as_alice("pueue status")
      expected = "running"
      assert expected in actual, f"expected pueue status to contain {expected}, but got {actual}"

      logout_alice()

    with subtest("GC root and profile"):
      # There should be a GC root and Home Manager profile and they should point
      # to the same path in the Nix store.
      gcroot = "/home/alice/.local/state/home-manager/gcroots/current-home"
      gcrootTarget = machine.succeed(f"readlink {gcroot}")

      profile = "/home/alice/.local/state/nix/profiles"
      profileTarget = machine.succeed(f"readlink {profile}/home-manager")
      profile1Target = machine.succeed(f"readlink {profile}/{profileTarget}")

      assert gcrootTarget == profile1Target, \
        f"expected GC root and profile to point to same, but pointed to {gcrootTarget} and {profile1Target}"
  '';
}