From a41498108911c19d25c3030199253c1c0a0682c6 Mon Sep 17 00:00:00 2001
From: Johannes Kirschbauer <hsjobeki@gmail.com>
Date: Mon, 7 Oct 2024 22:31:46 +0200
Subject: [PATCH] Init: eval clanmodule interface with roles

---
 lib/default.nix                       |  5 +-
 lib/eval-clan-modules/default.nix     | 74 +++++++++++++++++++++++++--
 lib/inventory/interface-to-schema.nix |  5 +-
 3 files changed, 79 insertions(+), 5 deletions(-)

diff --git a/lib/default.nix b/lib/default.nix
index 23556ee91..1faa640d0 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -4,8 +4,11 @@
   nixpkgs,
   ...
 }:
+let
+  eval = import ./eval-clan-modules { inherit clan-core nixpkgs lib; };
+in
 {
-  evalClanModules = import ./eval-clan-modules { inherit clan-core nixpkgs lib; };
+  inherit (eval) evalClanModules evalClanModulesWithRoles;
   buildClan = import ./build-clan { inherit lib nixpkgs clan-core; };
   facts = import ./facts.nix { inherit lib; };
   inventory = import ./inventory { inherit lib clan-core; };
diff --git a/lib/eval-clan-modules/default.nix b/lib/eval-clan-modules/default.nix
index 50c5c2c9b..f82009a31 100644
--- a/lib/eval-clan-modules/default.nix
+++ b/lib/eval-clan-modules/default.nix
@@ -19,7 +19,7 @@ let
 
   # This function takes a list of module names and evaluates them
   # evalClanModules :: [ String ] -> { config, options, ... }
-  evalClanModules =
+  evalClanModulesLegacy =
     modulenames:
     let
       evaled = lib.evalModules {
@@ -32,6 +32,74 @@ let
         ] ++ (map (name: clanModules.${name}) modulenames);
       };
     in
-    evaled;
+    lib.warn ''
+      EvalClanModules doesn't respect role specific interfaces.
+
+      The following {module}/default.nix file trying to be imported.
+
+      Modules: ${builtins.toJSON modulenames}
+
+      This might result in incomplete or incorrect interfaces.
+
+      FIX: Use evalClanModuleWithRole instead.
+    '' evaled;
+
+  /*
+    This function takes a list of module names and evaluates them
+    Returns a set of interfaces as described below:
+
+    Fn :: { ${moduleName} = Module; } -> {
+      ${moduleName} :: {
+        ${roleName}: JSONSchema
+      }
+    }
+  */
+  evalClanModulesWithRoles =
+    clanModules:
+    let
+      getRoles =
+        modulePath:
+        let
+          rolesDir = "${modulePath}/roles";
+        in
+        if builtins.pathExists rolesDir then
+          lib.pipe rolesDir [
+            builtins.readDir
+            (lib.filterAttrs (_n: v: v == "regular"))
+            lib.attrNames
+            (lib.filter (fileName: lib.hasSuffix ".nix" fileName))
+            (map (fileName: lib.removeSuffix ".nix" fileName))
+          ]
+        else
+          [ ];
+      res = builtins.mapAttrs (
+        moduleName: module:
+        let
+          # module must be a path to the clanModule root by convention
+          # See: clanModules/flake-module.nix
+          roles =
+            assert lib.isPath module;
+            getRoles module;
+        in
+        lib.listToAttrs (
+          lib.map (role: {
+            name = role;
+            value =
+              (lib.evalModules {
+                modules = [
+                  baseModule
+                  clan-core.nixosModules.clanCore
+                  # Role interface
+                  (module + "/roles/${role}.nix")
+                ];
+              }).options.clan.${moduleName} or { };
+          }) roles
+        )
+      ) clanModules;
+    in
+    res;
 in
-evalClanModules
+{
+  evalClanModules = evalClanModulesLegacy;
+  inherit evalClanModulesWithRoles;
+}
diff --git a/lib/inventory/interface-to-schema.nix b/lib/inventory/interface-to-schema.nix
index 709a0d2d7..0c2a7f215 100644
--- a/lib/inventory/interface-to-schema.nix
+++ b/lib/inventory/interface-to-schema.nix
@@ -94,9 +94,10 @@ let
       rolesOf =
         moduleName:
         let
+          # null | [ string ]
           roles = getRoles self.clanModules.${moduleName};
         in
-        if roles == null then [ "default" ] else roles;
+        if roles == null then [ ] else roles;
       moduleServices = lib.mapAttrs moduleToService (
         lib.filterAttrs (n: _v: rolesOf n != [ ]) modulesSchema
       );
@@ -129,4 +130,6 @@ in
     }
   */
   schemaWithModules = schema;
+
+  inherit modulesSchema;
 }