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

  outputs =
    inputs@{
      nixpkgs,
      nixpkgsUnstable,
      home-manager,
      nixos-hardware,
      agenix,
      simple-nixos-mailserver,
      git-hooks,
      ...
    }:
    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 ];
        }
        {
          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
    rec {
      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; };
        };
      };

      checks.${system} = {
        pre-commit-check = git-hooks.lib.${system}.run {
          src = ./.;
          hooks = {
            # Check formatting of flake.nix
            nixfmt-rfc-style = {
              enable = true;
              files = "^flake\\.nix$";
            };
            # Check for dead code in flake.nix
            deadnix = {
              enable = true;
              files = "^flake\\.nix$";
            };
            # Flake-specific checks
            flake-checker.enable = true;
          };
        };
      };

      devShells.${system}.default =
        let
          pkgs = nixpkgs.legacyPackages.${system};
        in
        pkgs.mkShell {
          inherit (checks.${system}.pre-commit-check) shellHook;
          buildInputs = checks.${system}.pre-commit-check.enabledPackages;
        };
    };
}