nix-config/flake.nix

{
  description = "A somewhat huge home-manager configuration using Nix Flakes.";

  inputs = {
    # Flake inputs
    agenix.url = "github:ryantm/agenix";
    home.url = "github:nix-community/home-manager";

    # Nixpkgs branches
    master.url = "github:nixos/nixpkgs/master";
    stable.url = "github:nixos/nixpkgs/nixos-23.05";
    unstable.url = "github:nixos/nixpkgs/nixpkgs-unstable";

    # Default Nixpkgs for packages and modules
    nixpkgs.follows = "master";

    # Minimize duplicate instances of inputs
    agenix.inputs.nixpkgs.follows = "nixpkgs";
    home.inputs.nixpkgs.follows = "nixpkgs";
    nix.inputs.nixpkgs.follows = "nixpkgs";
  };

  outputs = { self, home, nixpkgs, ... }@inputs:
    let
      config = {
        allowBroken = false;
        allowUnfree = true;
        allowUnfreePredicate = _: true;
        tarball-ttl = 0;

        # WTF: don't do this kids...
        # replaceStdenv = { pkgs }: pkgs.optimizedV3Stdenv;

        /*
          NOTE: experimental option, disable if you don't know what this does
          See https://github.com/NixOS/rfcs/pull/62 for more information.
          */
        contentAddressedByDefault = false;
      };

      importNixFiles = path: with nixpkgs.lib; map import (__filter (hasSuffix "nix") (filesystem.listFilesRecursive path));

      overlays = with inputs; [
        (final: prev:
          let inherit (final) system; in
          {
            /*
                Nixpkgs branches, replace when https://github.com/NixOS/nixpkgs/pull/160061 is live.
                One can access these branches like so:
                `pkgs.stable.mpd'
                `pkgs.master.linuxPackages_xanmod'
            */
            master = import master { inherit config system; };
            unstable = import unstable { inherit config system; };
            stable = import stable { inherit config system; };
          })

        # Overlays provided by inputs
        inputs.nixpkgs-f2k.overlays.stdenvs
      ]
      # Overlays from ./overlays directory
      ++ (importNixFiles ./overlays);
    in
    flake-parts.lib.mkFlake { inherit inputs; } {
      flake = {
        homeConfigurations = {
          devvie = import ./users/devvie {
            inherit config nixpkgs home overlays inputs;
          };

          #omni = import ./users/omni {
          #  inherit config nixpkgs home overlays inputs;
          #};
        };
      };

      systems = [ "x86_64-linux" ];

      perSystem = { system, ... }: {
        formatter = inputs.nixpkgs-fmt.defaultPackage.${system};
      };
    };

  nixConfig = {
    commit-lockfile-summary = "flake: bump inputs";

    substituters = [
      "https://cache.nixos.org?priority=10"
      "https://cache.ngi0.nixos.org/"
      "https://nix-community.cachix.org?priority=5"
      "https://nixpkgs-wayland.cachix.org"
      "https://fortuneteller2k.cachix.org"
    ];
  };
}