NixOS/modules/dev/nix.nix

{
  config,
  inputs,
  lib,
  pkgs,
  ...
}:
let
  shellType = config.my.shell.type;
  packages = builtins.attrValues {
    inherit (pkgs)
      nixfmt-rfc-style # formatting
      cachix # binary cache management
      nixd # language server for Nix
      deadnix # detext unused/uneeded dependencies
      statix # linter for Nix expressions
      ;
  };
in
{
  options = {
    my.dev.nix = {
      enable = lib.mkEnableOption "Install Nix tooling globally";
      users = lib.mkOption {
        type = lib.types.either lib.types.str (lib.types.listOf lib.types.str);
        default = config.my.toggleUsers.dev;
        description = "Users to install Nix packages for";
      };
    };
    devShells.nix = lib.mkOption {
      type = lib.types.package;
      default = pkgs.mkShell {
        inherit packages;
        name = "nix-dev-shell";
        shellHook = ''
          echo "❄️  Nix dev environment"
        '';
      };
      description = "Nix/NixOS development shell with formatter, linter, LSP, and Cachix";
    };
  };
  config = lib.mkIf config.my.dev.nix.enable {
    users.users = inputs.self.lib.mkUserAttrs lib config.my.dev.nix.users { inherit packages; };
    home-manager.users = inputs.self.lib.mkHomeManagerUsers lib config.my.dev.nix.users (_user: {
      programs.${shellType}.shellAliases = inputs.self.lib.mergeAliases inputs.self.lib.commonAliases {
        nixformat = ''
          deadnix -e && \
          nix run nixpkgs#nixfmt-tree && \
          statix fix
        '';
        nix-push-cache = ''
          nix build $NH_FLAKE#nixosConfigurations.${config.networking.hostName}.config.system.build.toplevel \
          --print-out-paths --fallback --max-jobs 100 --cores 0 |
          nix run nixpkgs#attic-client -- push lan:nixos --stdin
        '';
      };
    });
  };
}