nixos/modules/users.nix

{
  config,
  pkgs,
  lib,
  homeConfigurations,
  ...
}:
with lib; {
  options.elss.users = {
    enable = mkEnableOption "elss specific user configuration";

    x11.enable = mkEnableOption "Activate XSession related options in user-configs";

    dunst.enable = mkEnableOption "Activate Dunst";

    users = mkOption {
      description = "logins of non-admin users to configure";
      type = types.listOf types.str;
    };
    admins = mkOption {
      description = "logins of admin users to configure";
      type = types.listOf types.str;
    };
    meta = mkOption {
      type =
        types.attrsOf
        (types.submodule {
          options = {
            description = mkOption {
              type = types.str;
              description = "full name of the user";
            };
            hashedPassword =
              mkOption
              {
                type = types.str;
                default = null;
                description = "hashed password, only required for admins";
              };
            publicKeys = mkOption {
              type = types.listOf types.str;
              description = "SSH public keys for the user";
            };
            mailAddress = mkOption {
              type = types.str;
              description = "Email address of the user";
            };
            extraGroups = mkOption {
              type = types.listOf types.str;
              description = "additional groups to add";
              default = [];
            };

            git = mkOption {
              type = types.submodule {
                options = {
                  key = mkOption {
                    type = types.str;
                    example = "0xBEEE1234";
                    default = "C804A9C1B7AF8256";
                    description = "Signkey for git commits";
                  };
                  gpgsm = mkOption {
                    type = types.bool;
                    default = false;
                    description = "Whether to use gpgsm for commit signatures";
                  };
                  signDefault = mkOption {
                    type = types.bool;
                    default = false;
                    description = "Whether to force signing commits or not";
                  };
                };
              };
            };
          };
        });
    };
  };

  config = let
    cfg = config.elss.users;
    inherit (elss.withConfig config) mapAdmins mapUsers mapAllUsersAndRoot mapAllUsers;

    getMeta = login:
      builtins.getAttr login cfg.meta;
    mkAdmin = login:
      mkMerge [
        (mkUser login)
        {
          extraGroups = ["wheel"];
          inherit (getMeta login) hashedPassword;
        }
      ];
    mkUser = login: let
      meta = getMeta login;
    in {
      inherit (meta) description;
      isNormalUser = true;
      home = "/home/${login}";
      extraGroups = meta.extraGroups;
      openssh.authorizedKeys.keys = meta.publicKeys;
    };

    mkGitUser = login: let
      meta = getMeta login;
    in {
      programs.git = {
        userEmail = meta.mailAddress;
        userName = meta.description;
        extraConfig = {
          gpg = lib.mkIf meta.git.gpgsm {
            format = "x509";
            program = "${pkgs.gnupg}/bin/gpgsm";
          };
          user = {
            signingKey = meta.git.key;
          };
          commit = {
            gpgsign = meta.git.signDefault;
          };
        };
      };
    };

    mkX11User = login: let
      meta = getMeta login;
    in
      mkIf (cfg.x11.enable)
      {
        xsession = {
          numlock.enable = true;
          profileExtra = ''
            if [ $(hostname) = 'stel-xps' ]; then
              brightnessctl s 50%
            fi
          '';
        };
        home.file.".background-image".source = ../common/wallpaper/nix-wallpaper-nineish-dark-gray.png;

        services = {
          blueman-applet.enable = true;
          network-manager-applet.enable = true;
          dunst.enable = true;
        };
      };
  in
    mkIf (cfg.enable)
    {
      assertions = let
        cfg = config.elss.users;
      in [
        {
          assertion = mutuallyExclusive cfg.users cfg.admins;
          message = "elss.users.users and elss.users.admins are mutually exclusive";
        }
        {
          assertion =
            all (hash: hash != "")
            (catAttrs "hashedPassword" (attrVals cfg.admins cfg.meta));
          message = "No admin without password";
        }
        {
          assertion = length (cfg.admins) > 0;
          message = "One admin needed at least";
        }
      ];

      users = {
        mutableUsers = false;
        users = mkMerge [
          (mapAdmins mkAdmin)
          (mapUsers mkUser)
        ];
      };
      home-manager = {
        useUserPackages = true;
        useGlobalPkgs = true;
        users = mkMerge [
          (mapAllUsers mkX11User)
          (mapAllUsers mkGitUser)
          (mapAllUsersAndRoot (login:
            mkMerge [
              {config.home.stateVersion = mkDefault "21.11";}
              (
                if homeConfigurations ? "${login}"
                then homeConfigurations."${login}"
                else {}
              )
            ]))
        ];
      };
    };
}