# ============================================================================
# Common Host Module
# ============================================================================
# This module contains all the common configuration shared by all host types.
# It is automatically imported by the fleet generator for every host.

{ inputs }:
{
  config,
  lib,
  ...
}:
{
  imports = [
    ./boot.nix
    ./user-config.nix
    ../sw
    ../users.nix
    inputs.home-manager.nixosModules.home-manager
    inputs.agenix.nixosModules.default
    inputs.disko.nixosModules.disko
  ];

  # Define garbage collection options here since they're consumed in this module
  options.athenix = {
    forUser = lib.mkOption {
      type = lib.types.nullOr lib.types.str;
      default = null;
      description = ''
        Convenience option to configure a host for a specific user.
        Automatically enables the user (sets athenix.users.username.enable = true).
        Value should be a username from athenix.users.accounts.
      '';
    };

    system.gc = {
      enable = lib.mkOption {
        type = lib.types.bool;
        default = true;
        description = "Whether to enable automatic garbage collection.";
      };
      frequency = lib.mkOption {
        type = lib.types.str;
        default = "weekly";
        description = "How often to run garbage collection (systemd timer format).";
      };
      retentionDays = lib.mkOption {
        type = lib.types.int;
        default = 30;
        description = "Number of days to keep old generations before deletion.";
      };
      optimise = lib.mkOption {
        type = lib.types.bool;
        default = true;
        description = "Whether to automatically optimize the Nix store.";
      };
    };

    host.buildMethods = lib.mkOption {
      type = lib.types.listOf lib.types.str;
      default = [ "installer-iso" ];
      description = ''
        List of allowed build methods for this host (used by installer/artifacts.nix).
        Supported methods:
        - "installer-iso": Generates an auto-install ISO that installs this configuration to disk.
        - "iso": Generates a live ISO (using nixos-generators).
        - "ipxe": Generates iPXE netboot artifacts (kernel, initrd, script).
        - "lxc": Generates an LXC container tarball.
        - "proxmox": Generates a Proxmox VMA archive.
      '';
    };
  };

  config = lib.mkMerge [
    # Enable forUser if specified
    (lib.mkIf (config.athenix.forUser != null) {
      athenix.users.${config.athenix.forUser}.enable = true;
    })

    {
      system.stateVersion = "25.11";

      nix.settings.experimental-features = [
        "nix-command"
        "flakes"
      ];

      # Automatic Garbage Collection
      nix.gc = lib.mkIf config.athenix.system.gc.enable {
        automatic = true;
        dates = config.athenix.system.gc.frequency;
        options = "--delete-older-than ${toString config.athenix.system.gc.retentionDays}d";
      };

      # Optimize storage
      nix.optimise.automatic = config.athenix.system.gc.optimise;
    }
  ];
}