Nomarchy/modules/nixos/default.nix

# Nomarchy — reusable system layer (NixOS 26.05).
#
# This module is the distro: import it from any host (see
# nixosModules.nomarchy in flake.nix) and layer your machine specifics
# (bootloader, hostname, users, hardware) on top. Host concerns are
# deliberately NOT set here. Everything user-facing (Hyprland config,
# Waybar, Ghostty, theming) lives in modules/home.
{ config, lib, pkgs, ... }:

let
  cfg = config.nomarchy.system;
in
{
  imports = [ ./options.nix ];

  config = {
    # ── Wayland session: Hyprland ────────────────────────────────────
    # Installs the binary, registers the session, wires up
    # xdg-desktop-portal-hyprland. Configuration is Home Manager's job.
    programs.hyprland.enable = lib.mkDefault true;

    xdg.portal = {
      enable = lib.mkDefault true;
      extraPortals = [ pkgs.xdg-desktop-portal-gtk ]; # file pickers, etc.
    };

    services.greetd = lib.mkIf cfg.greeter.enable {
      enable = lib.mkDefault true;
      settings = {
        default_session = {
          command = lib.mkDefault "${pkgs.tuigreet}/bin/tuigreet --time --remember --cmd Hyprland";
          user = "greeter";
        };
        # Boot straight into the session once; logout → normal greeter.
        initial_session = lib.mkIf (cfg.greeter.autoLogin != null) {
          command = "Hyprland";
          user = cfg.greeter.autoLogin;
        };
      };
    };

    # ── Audio: Pipewire ──────────────────────────────────────────────
    security.rtkit.enable = lib.mkDefault cfg.audio.enable;
    services.pulseaudio.enable = lib.mkDefault false;
    services.pipewire = lib.mkIf cfg.audio.enable {
      enable = lib.mkDefault true;
      alsa.enable = true;
      alsa.support32Bit = true;
      pulse.enable = true;
      wireplumber.enable = true;
    };

    # ── Desktop services ─────────────────────────────────────────────
    security.polkit.enable = lib.mkDefault true;
    services.gnome.gnome-keyring.enable = lib.mkDefault true;
    services.dbus.enable = lib.mkDefault true;
    services.upower.enable = lib.mkDefault true;
    networking.networkmanager.enable = lib.mkDefault true;

    hardware.bluetooth.enable = lib.mkDefault cfg.bluetooth.enable;
    services.blueman.enable = lib.mkDefault cfg.bluetooth.enable;

    # ── BTRFS timeline snapshots (ported from the previous iteration) ─
    # Guarded on the actual filesystem so enabling it on an ext4 machine
    # is a clean no-op rather than a failing timer.
    services.snapper.configs = lib.mkIf
      (cfg.snapper.enable && (config.fileSystems."/".fsType or "") == "btrfs")
      {
        root = {
          SUBVOLUME = "/";
          TIMELINE_CREATE = true;
          TIMELINE_CLEANUP = true;
          TIMELINE_LIMIT_HOURLY = "5";
          TIMELINE_LIMIT_DAILY = "7";
          TIMELINE_LIMIT_WEEKLY = "0";
          TIMELINE_LIMIT_MONTHLY = "0";
          TIMELINE_LIMIT_YEARLY = "0";
        };
      };

    # ── Fonts ────────────────────────────────────────────────────────
    fonts = {
      packages = with pkgs; [
        nerd-fonts.jetbrains-mono
        inter
        noto-fonts
        noto-fonts-color-emoji
      ];
      fontconfig.defaultFonts = {
        monospace = lib.mkDefault [ "JetBrainsMono Nerd Font" ];
        sansSerif = lib.mkDefault [ "Inter" ];
        emoji = lib.mkDefault [ "Noto Color Emoji" ];
      };
    };

    # ── Essential packages ───────────────────────────────────────────
    environment.systemPackages = with pkgs; [
      nomarchy-theme-sync # provided by overlays.default
      git
      vim
      wget
      curl
      jq
      brightnessctl
      playerctl
      pamixer
      wl-clipboard
      grim
      slurp
    ] ++ lib.optional (cfg.snapper.enable && (config.fileSystems."/".fsType or "") == "btrfs")
      # Snapshot, then rebuild — rollback material for system changes
      # (theme changes don't need it; HM generations already roll back).
      (pkgs.writeShellScriptBin "nixos-rebuild-snap" ''
        if [ "$(id -u)" -ne 0 ]; then
          echo "This script must be run as root (use sudo)" >&2
          exit 1
        fi
        echo "Creating pre-rebuild snapshot..."
        ${pkgs.snapper}/bin/snapper -c root create \
          -d "Pre-rebuild $(date +'%Y-%m-%d %H:%M:%S')" \
          --cleanup-algorithm number
        echo "Rebuilding..."
        nixos-rebuild switch --flake /etc/nixos#default "$@"
      '');

    # ── Nix itself ───────────────────────────────────────────────────
    nix = {
      settings = {
        experimental-features = [ "nix-command" "flakes" ];
        auto-optimise-store = lib.mkDefault true;
      };
      gc = {
        automatic = lib.mkDefault true;
        dates = lib.mkDefault "weekly";
        options = lib.mkDefault "--delete-older-than 14d";
      };
    };
  };
}