dotfiles/hosts/default.nix

{
  nixpkgs,
  agenix,
  home-manager,
  flake-utils,
  nixgl,
  rust-overlay,
  flake-compat,
  pkgs,
  lib,
  proj_root,
  nixosDefaultVersion ? "22.05",
  defaultSystem ? "x86_64-linux",
  ...
} @ finalInputs: let
  config = {
    bao.metadata = {
      # req
      hostName = "bao";
      # opts
      ssh_pubkey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIBuAaAE7TiQmMH300VRj/pYCri1qPmHjd+y9aX2J0Fs";
      nixosVersion = "22.11";
      system = "x86_64-linux";
      preset = "base";
    };
    # TODO: add override so that we can add wsl config on top
    bao.nixosConfig = {
      modules = [
        (import ../modules/nvgpu.sys.nix)
        (import ../modules/kde.sys.nix)
        (import ../modules/pulseaudio.sys.nix)
        (import ../modules/storage.perso.sys.nix)
      ];
    };
  };
  propagate = hostConfig @ {
    metadata,
    nixosConfig,
  }: let
    # req
    inherit (metadata) hostName;
    # opts
    ssh_pubkey = lib.attrByPath ["ssh_pubkey"] null metadata; # metadata.ssh_pubkey??undefined
    users = lib.attrByPath ["users"] {} metadata;
    nixosVersion = lib.attrByPath ["nixosVersion"] nixosDefaultVersion metadata;
    system = lib.attrByPath ["system"] defaultSystem metadata;
    preset = lib.attrByPath ["preset"] "base" metadata;
    # infer
    hardwareConfig = import "${proj_root.hosts.path}/${hostName}/hardware-configuration.nix";
    # alias to prevent infinite recursion
    _nixosConfig = nixosConfig;
  in {
    inherit hostName ssh_pubkey users nixosVersion system preset hardwareConfig;
    nixosConfig =
      _nixosConfig
      // {
        inherit system;
        modules =
          [
            {
              config._module.args = {
                inherit proj_root;
                my-lib = finalInputs.lib;
              };
            }
            hardwareConfig
            {
              system.stateVersion = nixosVersion;
              networking.hostName = hostName;
              users.users = users;
            }
            {
              imports = [agenix.nixosModule];
              environment.systemPackages = [agenix.defaultPackage.x86_64-linux];
            }
            (import "${proj_root.modules.path}/secrets.nix")
            (import "${proj_root.modules.path}/${preset}.sys.nix")
          ]
          ++ _nixosConfig.modules;
      };
  };
  # we are blessed by the fact that we engulfed nixpkgs.lib.* at top level
  mkHostFromPropagated = propagatedHostConfig @ {nixosConfig, ...}: nixpkgs.lib.nixosSystem nixosConfig;
  mkHost = hostConfig: (lib.pipe [propagate mkHostFromPropagated] hostConfig);
  trimNull = lib.filterAttrsRecursive (name: value: value != null);
  flattenPubkey = lib.mapAttrs (hostName: meta_config: meta_config.metadata.ssh_pubkey);
in {
  nixosConfigurations = lib.mapAttrs (name: hostConfig: mkHost hostConfig) config;
  # {bao = "ssh-ed25519 ..."; another_host = "ssh-rsa ...";}
  pubKeys = lib.getPubkey config;
}