nix-config/flake.nix

{
  description = "EmergentMind's Nix-Config Starter";
  outputs = {
    self,
    nixpkgs,
    ...
  } @ inputs: let
    inherit (self) outputs;
    inherit (nixpkgs) lib;

    #
    # ========= Architectures =========
    #
    # NOTE(starter): Comment or uncomment architectures below as required by your hosts.
    forAllSystems = nixpkgs.lib.genAttrs [
      "x86_64-linux"
      "aarch64-darwin"
    ];

    #
    # ========= Host Config Functions =========
    #
    # Handle a given host config based on whether its underlying system is nixos or darwin
    mkHost = host: isDarwin: {
      ${host} = let
        func =
          if isDarwin
          then inputs.nix-darwin.lib.darwinSystem
          else lib.nixosSystem;
        systemFunc = func;
      in
        systemFunc {
          specialArgs = {
            inherit
              inputs
              outputs
              isDarwin
              ;

            # ========== Extend lib with lib.custom ==========
            # This approach allows lib.custom to propagate into hm
            # see: https://github.com/nix-community/home-manager/pull/3454
            lib = nixpkgs.lib.extend (self: super: {custom = import ./lib {inherit (nixpkgs) lib;};});
          };
          modules = [
            ./hosts/${
              if isDarwin
              then "darwin"
              else "nixos"
            }/${host}
          ];
        };
    };
    # Invoke mkHost for each host config that is declared for either nixos or darwin
    mkHostConfigs = hosts: isDarwin: lib.foldl (acc: set: acc // set) {} (lib.map (host: mkHost host isDarwin) hosts);
    # Return the hosts declared in the given directory
    readHosts = folder: lib.attrNames (builtins.readDir ./hosts/${folder});
  in {
    #
    # ========= Overlays =========
    #
    # Custom modifications/overrides to upstream packages.
    overlays = import ./overlays {
      inherit inputs;
      inherit lib;
    };

    #
    # ========= Host Configurations =========
    #
    # Building configurations is available through `just rebuild` or `nixos-rebuild --flake .#hostname`
    # NOTE(starter): Only uncomment darwinConfigurations if you actually have a host module configured in `./hosts/darwin`
    nixosConfigurations = mkHostConfigs (readHosts "nixos") false;
    #darwinConfigurations = mkHostConfigs (readHosts "darwin") true;

    #
    # ========= Packages =========
    #
    # Add custom packages to be shared or upstreamed.
    packages = forAllSystems (
      system: let
        pkgs = import nixpkgs {
          inherit system;
          overlays = [self.overlays.default];
        };
      in
        lib.packagesFromDirectoryRecursive {
          callPackage = lib.callPackageWith pkgs;
          directory = ./pkgs/common;
        }
    );

    #
    # ========= Formatting =========
    #
    # Nix formatter available through 'nix fmt' https://nix-community.github.io/nixpkgs-fmt
    formatter = forAllSystems (system: nixpkgs.legacyPackages.${system}.nixfmt-rfc-style);

    #
    # ========= DevShell =========
    #
    # Custom shell for bootstrapping on new hosts, modifying nix-config, and secrets management
    devShells = forAllSystems (
      system:
        import ./shell.nix {
          pkgs = nixpkgs.legacyPackages.${system};
        }
    );
  };

  inputs = {
    #
    # ========= Official NixOS, Nix-Darwin, and HM Package Sources =========
    #
    # NOTE(starter): As with typical flake-based configs, you'll need to update the nixOS, hm,
    # and darwin version numbers below when new releases are available.
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
    # The next two inputs are for pinning nixpkgs to stable vs unstable regardless of what the above is set to.
    # This is particularly useful when an upcoming stable release is in beta because you can effectively
    # keep 'nixpkgs-stable' set to stable for critical packages while setting 'nixpkgs' to the beta branch to
    # get a jump start on deprecation changes.
    # See also 'stable-packages' and 'unstable-packages' overlays at 'overlays/default.nix"
    nixpkgs-stable.url = "github:NixOS/nixpkgs/nixos-24.11";
    nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";

    hardware.url = "github:nixos/nixos-hardware";
    home-manager = {
      url = "github:nix-community/home-manager/release-25.05";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    nixpkgs-darwin.url = "github:nixos/nixpkgs/nixpkgs-24.11-darwin";
    nix-darwin = {
      url = "github:lnl7/nix-darwin";
      inputs.nixpkgs.follows = "nixpkgs-darwin";
    };

    #
    # ========= Utilities =========
    #
    disko = {
      url = "github:nix-community/disko";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    nixos-hardware = {
      url = "github:NixOS/nixos-hardware/master";
    };

    nix4vscode = {
      url = "github:nix-community/nix4vscode";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    pre-commit-hooks = {
      url = "github:cachix/git-hooks.nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    devenv.url = "github:cachix/devenv";

    stylix = {
      url = "github:danth/stylix/release-25.05";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    #
    # ========= Extra Applications =========
    #
    zen-browser = {
      url = "github:0xc000022070/zen-browser-flake";
      inputs = {
        home-manager.follows = "home-manager";
        nixpkgs.follows = "nixpkgs";
      };
    };

    #
    # ========= Personal Repositories =========
    #
    # Private secrets repo.  See ./docs/secretsmgmt.md
    # Authenticates via ssh and use shallow clone
    # FIXME(starter): The url below points to the 'simple' branch of the public, nix-secrets-reference repository which is inherently INSECURE!
    # Replace the url with your personal, private nix-secrets repo.
    /*
       nix-secrets = {
      url = "git+ssh://git@github.com/emergentmind/nix-secrets-reference.git?ref=simple&shallow=1";
      inputs = { };
    };
    */
  };

  nixConfig = {
    extra-substituters = [
      "https://nix-community.cachix.org"
    ];
    extra-trusted-public-keys = [
      "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
    ];
  };
}