{
  description = "nixfiles";

  # `flake.lock` generation is not computable[1], thus it is impossible to add
  # helper functions to manage inputs.
  #
  # [1]: https://github.com/NixOS/nix/issues/5373
  inputs = {
    nixpkgs = {
      type = "github";
      owner = "NixOS";
      repo = "nixpkgs";
      ref = "nixpkgs-unstable";
    };

    nixpkgs-master = {
      type = "github";
      owner = "NixOS";
      repo = "nixpkgs";
      ref = "master";
    };

    nixpkgs-stable = {
      type = "github";
      owner = "NixOS";
      repo = "nixpkgs";
      ref = "release-22.05";
    };

    nixos-hardware = {
      type = "github";
      owner = "NixOS";
      repo = "nixos-hardware";
      ref = "master";
    };

    nur = {
      type = "github";
      owner = "nix-community";
      repo = "NUR";
      ref = "master";
    };

    home-manager = {
      type = "github";
      owner = "nix-community";
      repo = "home-manager";
      ref = "master";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        utils.follows = "flake-utils";
      };
    };

    emacs-overlay = {
      type = "github";
      owner = "nix-community";
      repo = "emacs-overlay";
      ref = "master";
      inputs = {
        flake-utils.follows = "flake-utils";
        nixpkgs.follows = "nixpkgs";
      };
    };

    dns-nix = {
      type = "github";
      owner = "kirelagin";
      repo = "dns.nix";
      ref = "master";
      inputs = {
        flake-utils.follows = "flake-utils";
        nixpkgs.follows = "nixpkgs";
      };
    };

    simple-nixos-mailserver = {
      type = "gitlab";
      owner = "simple-nixos-mailserver";
      repo = "nixos-mailserver";
      ref = "master";
      inputs = {
        nixpkgs-22_05.follows = "nixpkgs-stable";
        nixpkgs.follows = "nixpkgs";
        utils.follows = "flake-utils";
      };
    };

    # TODO Integrate into Altertmanager.
    # alertmanager-gotify = {
    #   type = "git";
    #   url = "https://git.mbosch.me/ma27/alertmanager-gotify";
    #   inputs = {
    #     flake-utils.follows = "flake-utils";
    #     nixpkgs.follows = "nixpkgs";
    #   };
    # };

    flake-utils = {
      type = "github";
      owner = "numtide";
      repo = "flake-utils";
      ref = "master";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    flake-registry = {
      type = "github";
      owner = "NixOS";
      repo = "flake-registry";
      ref = "master";
      flake = false;
    };

    agenix = {
      type = "github";
      owner = "ryantm";
      repo = "agenix";
      ref = "main";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    pre-commit-hooks = {
      type = "github";
      owner = "cachix";
      repo = "pre-commit-hooks.nix";
      ref = "master";
      inputs = {
        flake-utils.follows = "flake-utils";
        nixpkgs.follows = "nixpkgs";
      };
    };

    xmonad-ng = {
      type = "gitlab";
      owner = "azahi";
      repo = "xmonad-ng";
      ref = "master";
      # type = "path";
      # path = "/home/azahi/src/xmonad-ng";
      inputs = {
        flake-utils.follows = "flake-utils";
        nixpkgs.follows = "nixpkgs";
        pre-commit-hooks.follows = "pre-commit-hooks";
      };
    };

    azahi-cc = {
      type = "gitlab";
      owner = "azahi";
      repo = "azahi.cc";
      ref = "master";
      flake = false;
    };

    nmap-vulners = {
      type = "github";
      owner = "vulnersCom";
      repo = "nmap-vulners";
      ref = "master";
      flake = false;
    };

    nmap-vulscan = {
      type = "github";
      owner = "scipag";
      repo = "vulscan";
      ref = "master";
      flake = false;
    };
  };

  outputs = inputs:
    with inputs; let
      lib = nixpkgs.lib.extend (import ./lib);
    in
      flake-utils.lib.eachSystem ["x86_64-linux"]
      (system: let
        pkgs = import nixpkgs {
          inherit system;
          overlays = [self.overlays.default];
        };
      in {
        # TODO Add the rest of `self.overlay`.
        packages.default = pkgs.nixfiles.override {
          nixfilesSrc = ".";
        };

        apps.${system}.default = {
          type = "app";
          package = "${self.packages.${system}.nixfiles}/bin/nixfiles";
        };

        devShells.default = pkgs.mkShell {
          inherit (self.checks.${system}.preCommit) shellHook;
          packages = with pkgs; [
            pyright
            python310
            rnix-lsp
          ];
        };

        formatter = pkgs.alejandra;

        checks.preCommit = pre-commit-hooks.lib.${system}.run {
          src = ./.;
          hooks = {
            alejandra.enable = true;
            prettier = {
              enable = true;
              types = [];
              files = "\\.css";
            };
            shellcheck.enable = true;
            shfmt.enable = true;
            statix.enable = true;
          };
        };
      })
      // {
        inherit lib;

        nixosModules.nixfiles = import ./modules/nixfiles;

        nixosConfigurations =
          import ./configurations {inherit inputs lib;};

        overlays.default = final: _: {
          UltimMC = final.libsForQt5.callPackage ./packages/ultimmc.nix {};
          bruh = final.callPackage ./packages/bruh.nix {};
          mpv-autosub = final.callPackage ./packages/mpv-autosub.nix {};
          myip = final.callPackage ./packages/myip.nix {};
          nixfiles = final.callPackage ./packages/nixfiles.nix {};
          throttled = final.callPackage ./packages/throttled.nix {};
        };
      };
}