{ inputs, ... }:
{
  imports = [
    inputs.devshell.flakeModule
    inputs.pre-commit-hooks.flakeModule
    inputs.treefmt-nix.flakeModule
  ];

  perSystem =
    {
      config,
      pkgs,
      ...
    }:
    {
      pre-commit.settings.hooks.treefmt.enable = true;
      treefmt = {
        projectRootFile = "flake.nix";
        programs = {
          deadnix.enable = true;
          statix.enable = true;
          nixfmt.enable = true;
          rustfmt.enable = true;
        };
      };

      devshells.default = {
        packages = [
          pkgs.nix # Always use the nix version from this flake's nixpkgs version, so that nix-plugins (below) doesn't fail because of different nix versions.
        ];

        commands = [
          {
            package = config.treefmt.build.wrapper;
            help = "Format all files";
          }
          {
            package = pkgs.deploy;
            help = "Build and deploy this nix config to nodes";
          }
          {
            package = pkgs.nix-tree;
            help = "Interactively browse dependency graphs of Nix derivations";
          }
          {
            package = pkgs.nvd;
            help = "Diff two nix toplevels and show which packages were upgraded";
          }
          {
            package = pkgs.nix-diff;
            help = "Explain why two Nix derivations differ";
          }
          {
            package = pkgs.nix-output-monitor;
            help = "Nix Output Monitor (a drop-in alternative for `nix` which shows a build graph)";
          }
          {
            package = pkgs.writeShellApplication {
              name = "build";
              text = ''
                set -euo pipefail
                [[ "$#" -ge 1 ]] \
                  || { echo "usage: build <HOST>..." >&2; exit 1; }
                HOSTS=()
                for h in "$@"; do
                  HOSTS+=(".#nixosConfigurations.$h.config.system.build.toplevel")
                done
                nom build --no-link --print-out-paths --show-trace "''${HOSTS[@]}"
              '';
            };
            help = "Build a host configuration";
          }
        ];

        devshell.startup.pre-commit.text = config.pre-commit.installationScript;

        env = [
          {
            # Additionally configure nix-plugins with our extra builtins file.
            # We need this for our repo secrets.
            name = "NIX_CONFIG";
            value = ''
              plugin-files = ${pkgs.nix-plugins}/lib/nix/plugins
              extra-builtins-file = ${./..}/flake/extra-builtins.nix
            '';
          }
        ];
      };
    };
}