feat: try rework

validation/network_devices.nix

@@ -0,0 +1,40 @@
+let
+  lib = import <nixpkgs/lib>;
+
+  getDevices = net:
+    if net ? devices && builtins.isAttrs net.devices then
+      net.devices
+    else
+      throw "config/network.nix must define devices as an attrset.";
+
+  getLocalDevices = devices:
+    lib.filterAttrs (deviceName: device:
+      if !builtins.isAttrs device then
+        throw "Device '${deviceName}' must be an attrset."
+      else if !(device ? type) || !builtins.isString device.type then
+        throw "Device '${deviceName}' must define type as a string."
+      else if !(device ? ip) || !builtins.isString device.ip || device.ip == "" then
+        throw "Device '${deviceName}' must define ip as a non-empty string."
+      else
+        device.type == "local"
+    ) devices;
+
+  validateReservationShape = deviceName: reservation:
+    let
+      _ = if !builtins.isAttrs reservation then throw "Device '${deviceName}' reservation must be an attrset." else null;
+      _hw =
+        if reservation ? hw_address && builtins.isString reservation.hw_address && reservation.hw_address != "" then
+          null
+        else
+          throw "Device '${deviceName}' reservation must define hw_address as a non-empty string.";
+      _host =
+        if reservation ? hostname && builtins.isString reservation.hostname && reservation.hostname != "" then
+          null
+        else
+          throw "Device '${deviceName}' reservation must define hostname as a non-empty string.";
+    in
+      reservation;
+in
+{
+  inherit getDevices getLocalDevices validateReservationShape;
+}