dendritic/modules/nix-tools/rebuild.nix

{ self, inputs, ... }:
{
  flake.modules.nixos.rebuild =
    { config, pkgs, lib, ... }:
    let
      flakeDir = config.rebuild.flakeDir;
      echoCmd = lib.getExe' pkgs.coreutils "echo";
      hostnameCmd = "$(${lib.getExe pkgs.hostname} -s)";

      nfs = with pkgs; writeShellApplication {
        name = "nfs";
        runtimeInputs = [ coreutils hostname nh ];
        text = ''
          HOSTNAME=$(hostname -s)
          echo "Switching to the $HOSTNAME nixos profile"
          nh os switch "$@" "${flakeDir}#$HOSTNAME"
        '';
      };
      nfsu = with pkgs; writeShellApplication {
        name = "nfsu";
        runtimeInputs = [ nfs pkgs.git ];
        text = ''nfs --refresh "$@"'';
      };
    in
    {
      options.rebuild = {
        flakeDir = lib.mkOption {
          description = "Path to the flake directory.";
          type = lib.types.str;
          default = "/etc/nixos";
        };
      };

      config = {
        environment.systemPackages = with pkgs; [ nfs nfsu ];
      };
    };

  flake.modules.homeManager.rebuild =
    { config, pkgs, lib, ... }:
    let
      flakeDir = config.homeManagerFlakeDir;
      hostnameCmd = "$(${lib.getExe pkgs.hostname} -s)";

      flake-parts-check = with pkgs; writeShellApplication {
        name = "flake-parts-check";
        runtimeInputs = [ nix ];
        text = ''
          cd ${flakeDir}
          nix run "${flakeDir}#write-flake"
          nix flake check
        '';
      };

      nhms = with pkgs; writeShellApplication {
        name = "nhms";
        runtimeInputs = [ coreutils hostname nh ];
        text = ''
          HOSTNAME=$(hostname -s)
          echo "Switching to the $HOSTNAME home-manager profile"
          nh home switch ${flakeDir} -c "$HOSTNAME" "$@"
        '';
      };

      nhmu = with pkgs; writeShellApplication {
        name = "nhmu";
        runtimeInputs = [ nhms ];
        text = ''nhms --update'';
      };

      test-build = with pkgs; writeShellApplication {
        name = "test-build";
        runtimeInputs = [ coreutils nix hostname ];
        text = ''
          if [ -z "$1" ]; then
            HOSTNAME=$(hostname -s)
          else
            HOSTNAME="$1"
          fi
          echo "Testing the evaulation of the nixos config for $HOSTNAME"
          nix eval "${flakeDir}#nixosConfigurations.$HOSTNAME.config.system.build.toplevel.drvPath"
        '';
      };

      cleanup = with pkgs; writeShellApplication {
        name = "cleanup";
        runtimeInputs = [ coreutils home-manager nix ];
        text = ''
          set -e
          DAYS=$1
          if [ -z "$DAYS" ]; then
            echo "usage: cleanup <days>"
            exit 1
          fi
          home-manager expire-generations "-$DAYS days"
          nix profile wipe-history --older-than "''${DAYS}d"
          nix store gc
          nix store optimise
        '';
      };

    in
    {
      options = {
        homeManagerFlakeDir = lib.mkOption {
          description = "Path to the home-manager flake directory.";
          type = lib.types.str;
          default = "${config.xdg.configHome}/home-manager";
        };
      };

      config = {
        home.activation.printFlakeDir = lib.hm.dag.entryAfter ["writeBoundary"] ''
          run echo "Home Manager flake directory: ${flakeDir}"
        '';

        home.packages = with pkgs; [
          home-manager
          (symlinkJoin {
            name = "build-tools";
            paths = [
              flake-parts-check
              nhms
              nhmu
              test-build
              cleanup
            ];
          })
        ];
      };
    };
}