flake.nix

{
  description = "bold.daemon";

  # TODO: figure out how to make things pure (./pkgs...)

  inputs = {
    unstable = { url = "github:NixOS/nixpkgs/nixos-unstable"; };
    stable = { url = "github:NixOS/nixpkgs/nixos-21.11"; };
  };

  outputs = { self, unstable, stable }:
    let
      # use pkgs from unstable
      pkgs = (import unstable) { system = "x86_64-linux"; };
      #pkgs = (import unstable);

      hosts = (pkgs.lib.attrNames
        (pkgs.lib.filterAttrs (_: entryType: entryType == "directory")
          (builtins.readDir ./hosts)));

      build-sys = hostSet:
        (let
          parts = pkgs.lib.splitString "." hostSet;

          myName = builtins.elemAt parts 0;
          mySys = builtins.elemAt parts 1;
          myPkg = builtins.elemAt parts 2;

          hostSys = {
            system = mySys;
            modules = [
              (import (./default.nix))
              (import (./hosts + "/${myName}/configuration.nix"))
              (import (./hosts + "/${myName}/hardware-configuration.nix"))
            ];
          };
        in {
          name = myName;

          value = if myPkg == "unstable" then
            unstable.lib.nixosSystem hostSys
          else
            stable.lib.nixosSystem hostSys;
        });

    in {
      nixosConfigurations =
        builtins.listToAttrs (map (host: [ (build-sys host) ]) hosts);
    };
}