Initial commit

flake/den/modules/aspects/provides/import-tree.nix

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+{
+  inputs,
+  den,
+  ...
+}:
+{
+  den.provides.import-tree.description = ''
+    Recursively imports non-dendritic .nix files depending on their Nix configuration `class`.
+
+    This can be used to help migrating from huge existing setups.
+
+
+    ```
+      # this is at <repo>/modules/non-dendritic.nix
+      den.aspects.my-laptop.includes = [
+        (den._.import-tree._.host ../non-dendritic)
+      ]
+    ```
+
+    With following structure, it will automatically load modules depending on their class.
+
+    ```
+       <repo>/
+         modules/
+           non-dendritic.nix # configures this aspect
+         non-dendritic/ # name is just an example here
+           hosts/
+             my-laptop/
+               _nixos/          # a directory for `nixos` class
+                 auto-generated-hardware.nix # any nixos module
+               _darwin/ 
+                 foo.nix
+               _homeManager/
+                 me.nix
+    ```
+
+    ## Requirements
+
+      - inputs.import-tree
+
+    ## Usage
+
+      this aspect can be included explicitly on any aspect:
+
+          # example: will import ./disko/_nixos files automatically.
+          den.aspects.my-disko.includes = [ (den._.import-tree ./disko/) ];
+
+      or it can be default imported per host/user/home:
+
+          # load from ./hosts/<host>/_nixos
+          den.default.includes = [ (den._.import-tree._.host ./hosts) ];
+
+          # load from ./users/<user>/{_homeManager, _nixos}
+          den.default.includes = [ (den._.import-tree._.user ./users) ];
+
+          # load from ./homes/<home>/_homeManager
+          den.default.includes = [ (den._.import-tree._.home ./homes) ];
+
+      you are also free to create your own auto-imports layout following the implementation of these.
+  '';
+
+  den._.import-tree.__functor =
+    _: root:
+    # deadnix: skip
+    { class, aspect-chain }:
+    let
+      path = "${toString root}/_${class}";
+      aspect.${class}.imports = [ (inputs.import-tree path) ];
+    in
+    if builtins.pathExists path then aspect else { };
+
+  den._.import-tree.provides = {
+    host = root: { host, ... }: den._.import-tree "${toString root}/${host.name}";
+    home = root: { home, ... }: den._.import-tree "${toString root}/${home.name}";
+    user = root: { user, ... }: den._.import-tree "${toString root}/${user.name}";
+  };
+}