refactor: refactors nix-cue into the internal lib

flake.nix

@@ -2,12 +2,9 @@
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs";
     flake-utils.url = "github:numtide/flake-utils";
-    nix-cue.url = "github:jmgilman/nix-cue";
-    nix-cue.inputs.nixpkgs.follows = "nixpkgs";
-    nix-cue.inputs.flake-utils.follows = "flake-utils";
   };
 
-  outputs = { self, nixpkgs, flake-utils, nix-cue }:
+  outputs = { self, nixpkgs, flake-utils }:
     flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = import nixpkgs { inherit system; };
@@ -52,7 +49,7 @@
       in
       {
         # Load lib functions
-        lib = (import ./lib { inherit pkgs lib; }) // { nix-cue = nix-cue.lib.${system}; };
+        lib = (import ./lib { inherit pkgs lib; });
 
         # Load plugins
         plugins = import ./plugins { inherit pkgs lib; };

lib/default.nix

@@ -1,5 +1,7 @@
 { pkgs, lib }:
 {
+  eval = import ./eval.nix { inherit pkgs lib; };
+
   /* Combines the shellHook from multiple configurations into one.
   */
   mkShellHook = configs: builtins.concatStringsSep "\n" (pkgs.lib.catAttrs "shellHook" configs);

lib/eval.nix

@@ -0,0 +1,34 @@
+/*
+  Evaluates the given input files and data and returns a derivation which builds the result.
+*/
+{ pkgs, lib }:
+{ inputFiles, outputFile, data ? { }, cue ? pkgs.cue, ... }@args:
+with pkgs.lib;
+let
+  json = optionalString (data != { }) (builtins.toJSON data);
+
+  defaultFlags = {
+    outfile = "$out";
+  };
+  extraFlags = removeAttrs args [ "inputFiles" "outputFile" "data" "cue" ];
+
+  allFlags = defaultFlags // extraFlags;
+  allInputs = inputFiles ++ optionals (json != "") [ "json: $jsonPath" ];
+
+  flagsToString = name: value: if (builtins.isBool value) then "--${name}" else ''--${name} "${value}"'';
+  flagStr = builtins.concatStringsSep " " (attrValues (mapAttrs flagsToString allFlags));
+  inputStr = builtins.concatStringsSep " " allInputs;
+  cueEvalCmd = "cue eval ${flagStr} ${inputStr}";
+
+  result = pkgs.runCommand outputFile
+    ({
+      inherit json;
+      buildInputs = [ cue ];
+      passAsFile = [ "json" ];
+    } // optionalAttrs (json != "") { inherit json; passAsFile = [ "json" ]; })
+    ''
+      echo "nixago: Rendering output..."
+      ${cueEvalCmd}
+    '';
+in
+result

lib/template.nix

@@ -19,7 +19,7 @@ let
         inherit data files output shellHookExtra;
       }
     ];
-    specialArgs = ({ inherit (lib) nix-cue; inherit pkgs; } // flags);
+    specialArgs = ({ inherit pkgs; flakeLib = lib; } // flags);
   };
 in
 result.config

modules/template.nix

@@ -12,11 +12,11 @@
   option can be set to define extra shell commands to run when the configuration
   file is regenerated due to the underlying data changing.
 */
-{ config, lib, nix-cue, pkgs, ... }@args:
+{ config, lib, flakeLib, pkgs, ... }@args:
 with pkgs.lib;
 let
   inherit (lib) mkOption types;
-  flags = removeAttrs args [ "config" "lib" "nix-cue" "pkgs" "options" "specialArgs" ];
+  flags = removeAttrs args [ "config" "lib" "flakeLib" "pkgs" "options" "specialArgs" ];
   hook = ''
     # Check if the link is pointing to the existing derivation result
       if readlink ${config.output} >/dev/null \
@@ -41,9 +41,8 @@ in
     configFile = mkOption {
       type = types.package;
       description = "The generated configuration file";
-      default = nix-cue.eval
+      default = flakeLib.eval
         ({
-          inherit pkgs;
           inputFiles = config.files;
           outputFile = config.output;
           data = config.data;