From c93e9fda0fada3e4a48f416d1f38c5a57852e492 Mon Sep 17 00:00:00 2001
From: Pacman99 <pachum99@gmail.com>
Date: Sat, 1 May 2021 17:46:54 -0700
Subject: [PATCH] lib: init importers section

---
 lib/importers.nix | 64 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 lib/importers.nix

diff --git a/lib/importers.nix b/lib/importers.nix
new file mode 100644
index 00000000..ea07373d
--- /dev/null
+++ b/lib/importers.nix
@@ -0,0 +1,64 @@
+{ lib }:
+let
+  recImport = { dir, _import ? base: import "${dir}/${base}.nix" }:
+    lib.mapFilterAttrs
+      (_: v: v != null)
+      (n: v:
+        if n != "default.nix" && lib.hasSuffix ".nix" n && v == "regular"
+        then
+          let name = lib.removeSuffix ".nix" n; in lib.nameValuePair (name) (_import name)
+        else
+          lib.nameValuePair ("") (null))
+      (lib.safeReadDir dir);
+
+  mkProfileAttrs =
+    /**
+      Synopsis: mkProfileAttrs _path_
+
+      Recursively collect the subdirs of _path_ containing a default.nix into attrs.
+      This sets a contract, eliminating ambiguity for _default.nix_ living under the
+      profile directory.
+
+      Example:
+      let profiles = mkProfileAttrs ./profiles; in
+      assert profiles ? core.default; 0
+      **/
+    dir:
+    let
+      imports =
+        let
+          files = lib.safeReadDir dir;
+
+          p = n: v:
+            v == "directory"
+            && n != "profiles";
+        in
+        lib.filterAttrs p files;
+
+      f = n: _:
+        lib.optionalAttrs
+          (lib.pathExists "${dir}/${n}/default.nix")
+          { default = "${dir}/${n}"; }
+        // mkProfileAttrs "${dir}/${n}";
+    in
+    lib.mapAttrs f imports;
+
+in
+{
+  inherit recImport mkProfileAttrs;
+
+  pathsIn = dir:
+    let
+      fullPath = name: "${toString dir}/${name}";
+    in
+    map fullPath (lib.attrNames (lib.safeReadDir dir));
+
+  importHosts = dir:
+    recImport {
+      inherit dir;
+      _import = base: {
+        modules = import "${toString dir}/${base}.nix";
+      };
+    };
+}
+