flake.nix

{
  description = "Nix flake for \"too much bleeding-edge\" and unreleased packages (e.g., mesa_git, linux_cachyos, firefox_nightly, sway_git, gamescope_git). And experimental modules (e.g., HDR, duckdns).";

  inputs = {
    # For all users
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    # Used by "homeManagerModules" (for HM users)
    home-manager = {
      url = "github:nix-community/home-manager";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    # Thirdy-party republished repositories
    jovian = {
      url = "github:Jovian-Experiments/Jovian-NixOS";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    # Used by "schemas" output (for FlakeHub and "nix show", pinned)
    flake-schemas.url = "https://flakehub.com/f/DeterminateSystems/flake-schemas/=0.1.5.tar.gz";
    # Latest rustc
    fenix = {
      url = "github:nix-community/fenix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs =
    { self, nixpkgs, ... }@inputs:
    let
      eachSystem =
        accu: system:
        let
          pkgs = nixpkgs.legacyPackages.${system};
        in
        accu
        // {
          # Exposes the packages created by the overlay.
          legacyPackages = (accu.legacyPackages or { }) // {
            ${system} = accu.utils.applyOverlay { inherit pkgs; };
          };
          packages = (accu.packages or { }) // {
            ${system} = accu.utils.applyOverlay {
              inherit pkgs;
              onlyDerivations = true;
            };
          };

          # I would prefer if we had something stricter, with attribute alphabetical
          # sorting, and optimized for git's diffing. But this is the closer we have.
          formatter = (accu.formatter or { }) // {
            ${system} = import ./maintenance/formatter.nix pkgs;
          };
        };

      universals = {
        # To fix `nix show` and FlakeHub
        schemas = import ./maintenance/schemas { flakes = inputs; };

        # The stars: our overlay and our modules.
        overlays.default = import ./overlays { flakes = inputs; };
        overlays.cache-friendly = import ./overlays/cache-friendly.nix { flakes = inputs; };
        nixosModules = import ./modules/nixos { flakes = inputs; };
        homeModules = import ./modules/home-manager { flakes = inputs; };
        homeManagerModules = self.homeModules;

        # Dev stuff.
        utils = import ./shared/utils.nix {
          nyxOverlay = self.overlays.default;
          inherit (nixpkgs) lib;
        };
        inherit (import ./flake.nix) nixConfig;
      };
    in
    builtins.foldl' eachSystem universals [
      "x86_64-linux"
      "aarch64-linux"
      "aarch64-darwin"
    ];

  # Allows the user to use our cache when using `nix run <thisFlake>`.
  nixConfig = {
    extra-substituters = [
      "https://nix-community.cachix.org/"
      "https://chaotic-nyx.cachix.org/"
    ];
    extra-trusted-public-keys = [
      "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
      "chaotic-nyx.cachix.org-1:HfnXSw4pj95iI/n17rIDy40agHj12WfF+Gqk6SonIT8="
    ];
  };
}