nixos-config/flake-module.nix

# An opinionated module that creates flake outputs based on a known directory structure.
#
# cf. Convention over configuration
#
# TODO: Upstream this in some fashion. To srid/nixos-flake?
# cf. https://github.com/juspay/nix-dev-home/issues/86
{ inputs, self, ... }:
let
  inherit (inputs.nixpkgs) lib;
  forAllNixFiles = dir: f:
    lib.pipe dir [
      builtins.readDir
      (lib.filterAttrs (_: type: type == "regular"))
      (lib.mapAttrs' (fn: _:
        let name = lib.removeSuffix ".nix" fn; in
        lib.nameValuePair name (f "${dir}/${fn}")
      ))
    ];
in
{
  flake = {
    darwinConfigurations =
      forAllNixFiles "${self}/configurations/darwin"
        (fn: self.nixos-flake.lib.mkMacosSystem { home-manager = true; } fn);

    nixosConfigurations =
      forAllNixFiles "${self}/configurations/nixos"
        (fn: self.nixos-flake.lib.mkLinuxSystem { home-manager = true; } fn);

    darwinModules =
      forAllNixFiles "${self}/modules/darwin"
        (fn: fn);

    nixosModules =
      forAllNixFiles "${self}/modules/nixos"
        (fn: fn);

    homeModules =
      forAllNixFiles "${self}/modules/home"
        (fn: fn);

    overlays =
      forAllNixFiles "${self}/overlays"
        (fn: import fn self.nixos-flake.lib.specialArgsFor.common);
  };

  perSystem = { pkgs, ... }: {
    legacyPackages.homeConfigurations =
      forAllNixFiles "${self}/configurations/home"
        (fn: self.nixos-flake.lib.mkHomeConfiguration pkgs fn);
  };
}