feat: rewrite how nixlets work

lib/default.nix

@@ -3,11 +3,11 @@
   lib,
   ...
 } @ attrs:
-with lib; {
+with lib; rec {
   mkValues = file: {rawValues, ...} @ args:
     (lib.evalModules {
       specialArgs = {
-        utils = import ./. attrs;
+        utils = import ./utils.nix attrs;
       };
       modules = [
         file
@@ -23,58 +23,103 @@ with lib; {
     })
     .config;
 
-  mkNestedOption = options:
-    mkOption {
-      type = types.submodule {
-        inherit options;
-      };
-      default = {};
-    };
+  # wraps mkNixletInner to allow passing either a path or an attrset
+  mkNixlet = arg:
+    mkNixletInner (
+      if (builtins.typeOf arg) == "set"
+      then arg
+      else
+        {path = arg;}
+        // (
+          if builtins.pathExists "${arg}/nixlet.nix"
+          then (import "${arg}/nixlet.nix")
+          else throw "Nixlet at '${arg}' does not contain nixlet.nix and mkNixlet was called with just a path"
+        )
+    );
 
-  mkNixlet = path: let
-    utils = import ./. attrs;
-  in
-    {
-      rawValues,
-      project,
-      ...
-    } @ args: {
-      kubenix,
-      lib,
-      ...
-    } @ attrs: let
-      values = utils.mkValues "${path}/values.nix" args;
-    in {
-      imports = [path];
-      # make values accessible from every imported file
-      _module.args = {inherit values;};
-    };
+  mkNixletInner = {
+    path,
+    name,
+    version ? null,
+    description ? "",
+    defaultProject ? null,
+    ...
+  }: let
+    # TODO: just like with the values check the args here with the options system?
+  in {
+    inherit name version description path;
+    render = {
+      system,
+      project ? defaultProject,
+      overrides ? ({...}: {}),
+      values ? {},
+    }:
+      assert lib.assertMsg (project != null) "No default project set, please pass a project to the render method"; let
+        # every nixlet gets "nixlet" as arg with some useful data about itself
+        nixletArg = {
+          inherit name project version description;
+        };
+      in
+        (inputs.kubenix.evalModules.${system} {
+          module = {kubenix, ...}: {
+            imports = with kubenix.modules; [
+              k8s
+              helm
+              docker
+              files
+              ({...}: let
+                finalValues = mkValues "${path}/values.nix" {
+                  rawValues = values;
+                  nixlet = nixletArg;
+                };
+              in {
+                imports = [path];
+                _module.args.nixlet =
+                  {
+                    values = finalValues;
+                  }
+                  // nixletArg;
+              })
+              overrides
+            ];
+            kubenix.project = project;
+          };
+        })
+        .config
+        .kubernetes
+        .resultYAML;
+  };
 
-  renderNixlet = {
-    system,
-    project,
-    nixlet,
-    values ? {},
-    overrides ? {...}: {},
+  fetchNixlet = url: sha256: mkNixlet (builtins.fetchTarball {inherit url sha256;});
+
+  uploadNixletsToGitlab = {
+    pkgs,
+    projectId,
+    nixlets,
+    ...
   }:
-    (inputs.kubenix.evalModules.${system} {
-      module = {kubenix, ...}: {
-        imports = with kubenix.modules; [
-          k8s
-          helm
-          docker
-          files
-          (nixlet {
-            # all these args are available in values.nix
-            inherit project;
-            rawValues = values;
-          })
-          overrides
-        ];
-        kubenix.project = project;
-      };
-    })
-    .config
-    .kubernetes
-    .resultYAML;
+    pkgs.writeShellScriptBin "nixlets-upload" (
+      ''
+        if [[ -z "$AUTH_HEADER" ]]; then
+          echo "Must provide AUTH_HEADER environment variable!" 1>&2
+          exit 1
+        fi
+      ''
+      + lib.concatStringsSep "\n" (
+        builtins.map (nixlet:
+          with nixlet; ''
+            URL="https://gitlab.com/api/v4/projects/${projectId}/packages/generic/${name}/${version}/${name}.tar.gz"
+            if curl --output /dev/null --silent --head --fail --header "$AUTH_HEADER" $URL; then
+              echo "> Skipped ${name}@${version} because it already exists in the Package Registry"
+            else
+              echo "> Uploading new version ${name}@${version}"
+              ${pkgs.gnutar}/bin/tar -czf /tmp/${name}.tar.gz --mode='u+rwX' -C ${path} .
+              ${pkgs.curl}/bin/curl --header "$AUTH_HEADER" --upload-file "/tmp/${name}.tar.gz" "$URL"; echo;
+              ${pkgs.coreutils}/bin/rm -f /tmp/${nixlet.name}.tar.gz
+              echo "> Finished ${name}@${version}, see above"
+            fi
+          '')
+        nixlets
+      )
+    );
 }