nixos-config/flake.nix

{
  inputs.nixpkgs.url = "nixpkgs/nixos-unstable";
  inputs.impermanence.url = "github:nix-community/impermanence";

  outputs = { self, nixpkgs, impermanence }:
    let
      inherit (nixpkgs) lib;

      mypkgs = pkgs:
        self.lib.dirToAttrs ./pkgs (x: pkgs.callPackage x { }) //
        {
          iso = import lib/gen-iso.nix lib pkgs.system;
        };

      forAllSystems = lib.genAttrs [ "x86_64-linux" ];

      pins = {
        nix.registry.nixpkgs.to = {
          inherit (nixpkgs) rev;
          owner = "NixOS";
          repo = "nixpkgs";
          type = "github";
        };
        nix.registry.bck.to = {
          owner = "buckley310";
          repo = "nixos-config";
          type = "github";
        };
      };

    in
    {
      formatter = forAllSystems (system:
        nixpkgs.legacyPackages.${system}.nixpkgs-fmt);

      lib = {
        gen-ssh-config = import lib/gen-ssh-config.nix lib;
        ssh-keys = import lib/ssh-keys.nix;

        dirToAttrs = dir: f: lib.mapAttrs'
          (name: _: {
            name = lib.removeSuffix ".nix" name;
            value = f "${toString dir}/${name}";
          })
          (builtins.readDir dir);
      };

      nixosModules =
        {
          inherit pins;
          inherit (impermanence.nixosModules) impermanence;
          pkgs.nixpkgs.overlays = [ (_: mypkgs) ];
        } //
        self.lib.dirToAttrs ./modules import;

      nixosConfigurations = self.lib.dirToAttrs ./hosts
        (dir:
          let cfg = import dir;
          in lib.nixosSystem {
            inherit (cfg) system;
            modules =
              cfg.modules ++
              [{ networking.hostName = builtins.baseNameOf dir; }] ++
              (builtins.attrValues self.nixosModules);
          }
        );

      packages = forAllSystems (system:
        mypkgs nixpkgs.legacyPackages.${system});
    };
}