nixos/flake.nix

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
    nixpkgsUnstable.url = "github:NixOS/nixpkgs/nixos-unstable";
    nixos-hardware.url = "github:NixOS/nixos-hardware/master";
    home-manager = {
      url = "github:nix-community/home-manager/release-25.05";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    agenix.url = "github:ryantm/agenix";
    simple-nixos-mailserver.url = "gitlab:simple-nixos-mailserver/nixos-mailserver/nixos-25.05";
  };

  outputs =
    inputs@{
      nixpkgs,
      nixpkgsUnstable,
      home-manager,
      nixos-hardware,
      agenix,
      simple-nixos-mailserver,
      ...
    }:
    let
      system = "x86_64-linux";
      overlayUnstable = final: prev: {
        unstable = import nixpkgsUnstable {
          inherit system;
          config.allowUnfree = true;
          config.android_sdk.accept_license = true;
        };
      };

      # Common modules shared across all hosts
      commonModules = [
        agenix.nixosModules.default
        {
          environment.systemPackages = [ agenix.packages.${system}.default ];
        }
        (
          { config, pkgs, ... }:
          {
            nixpkgs.overlays = [ overlayUnstable ];
          }
        )
      ];

      # Common home-manager modules
      homeManagerModules = [
        home-manager.nixosModules.home-manager
        {
          home-manager.useGlobalPkgs = true;
          home-manager.useUserPackages = true;
        }
      ];

      # Helper function to create a host configuration
      mkHost =
        {
          hostPath,
          extraModules ? [ ],
          includeHomeManager ? true,
          specialArgs ? { },
        }:
        nixpkgs.lib.nixosSystem {
          inherit system specialArgs;
          modules =
            commonModules
            ++ (if includeHomeManager then homeManagerModules else [ ])
            ++ extraModules
            ++ [ hostPath ];
        };
    in
    {
      nixosConfigurations = {
        nixbox = mkHost {
          hostPath = ./hosts/nixbox;
        };

        flynode = mkHost {
          hostPath = ./hosts/flynode;
          extraModules = [ nixos-hardware.nixosModules.lenovo-thinkpad-z13-gen1 ];
        };

        thewordnerd = mkHost {
          hostPath = ./hosts/hub;
          extraModules = [ simple-nixos-mailserver.nixosModule ];
          specialArgs = { inherit inputs; };
        };

        garden = mkHost {
          hostPath = ./hosts/garden;
          includeHomeManager = false;
          specialArgs = { inherit inputs; };
        };
      };
    };
}