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

with lib;

let
  auto-installer = pkgs.writers.writeBash "auto-installer" ''
      set -o errexit
      set -o nounset
      set -o pipefail

      set -x

      if [[ "$(cat /proc/cmdline)" =~ nixos\.install=([^ ]+) ]]; then
        INSTALL="''${BASH_REMATCH[1]}"
      else
        echo "No install derivation found" >&2
        exit 1
      fi

      ${pkgs.retry}/bin/retry \
        --times 10 \
        --delay 15 \
        -- ${pkgs.nix}/bin/nix-store \
          --realize \
          --add-root /tmp/installer \
          "$INSTALL"

    exec /tmp/installer
  '';

in
{
  imports = [
    "${modulesPath}/installer/netboot/netboot-minimal.nix"

    ./shared/network.nix
    ./shared/cache.nix
    ./shared/users.nix
  ];

  _module.args = {
    name = "installer";
  };

  networking.useDHCP = mkForce true;

  services.getty.autologinUser = lib.mkForce "root";

  systemd.services."auto-install" = {
    description = "Automated NixOS installer";

    wants = [ "network-online.target" ];
    after = [ "network-online.target" ];

    conflicts = [ "getty@tty1.service" ];

    wantedBy = [ "multi-user.target" ];

    path = with pkgs; [ bash nix ];

    unitConfig = {
      AssertKernelCommandLine = "nixos.install";

      FailureAction = "force-reboot";
    };

    serviceConfig = {
      Type = "oneshot";

      ExecStart = auto-installer;

      StandardInput = "none";
      StandardOutput = "journal+console";
      StandardError = "journal+console";
    };
  };

  system.stateVersion = config.system.nixos.release;
}