From daaf0c2f8da6c7b5dc04dd62a3d98422f259551b Mon Sep 17 00:00:00 2001
From: "O. C. Taskin" <42993892+octvs@users.noreply.github.com>
Date: Fri, 13 Sep 2024 10:51:33 +0200
Subject: [PATCH] kanshi: add support for output aliases

- Add `services.kanshi.profiles.<name>.outputs.*.alias` to support new
  alias directive from kanshi [1].
  - Add an assertion to reject aliases not on global scope, which are
    not allowed on kanshi [2].
  - Add a new test to check alias rejection, `alias-assertion`.
- Add relevant coverage by modifying the existing "new-configuration"
  test.
- Kanshi also doesn't allow wildcards on global scope [3], correct the
  faulty test case.

[1]: https://git.sr.ht/~emersion/kanshi/commit/1ed86ce523553240ceb81e9d466b88d3554a66bb
[2]: https://git.sr.ht/~emersion/kanshi/tree/1605f7c81314d004104b7a1b149656947369c999/item/doc/kanshi.5.scd#L78
[3]: https://git.sr.ht/~emersion/kanshi/tree/1605f7c81314d004104b7a1b149656947369c999/item/doc/kanshi.5.scd#L80
---
 modules/services/kanshi.nix                   | 24 ++++++++++++++++---
 .../services/kanshi/alias-assertion.nix       | 18 ++++++++++++++
 tests/modules/services/kanshi/default.nix     |  1 +
 .../services/kanshi/new-configuration.conf    |  4 ++--
 .../services/kanshi/new-configuration.nix     |  6 ++---
 5 files changed, 45 insertions(+), 8 deletions(-)
 create mode 100644 tests/modules/services/kanshi/alias-assertion.nix

diff --git a/modules/services/kanshi.nix b/modules/services/kanshi.nix
index b503ffc7f..3b1bdf2cf 100644
--- a/modules/services/kanshi.nix
+++ b/modules/services/kanshi.nix
@@ -123,6 +123,15 @@ let
         '';
       };
 
+      alias = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        example = "laptopMonitor";
+        description = ''
+          Defines an alias for the output
+        '';
+      };
+
       adaptiveSync = mkOption {
         type = types.nullOr types.bool;
         default = null;
@@ -135,15 +144,16 @@ let
     };
   };
 
-  outputStr =
-    { criteria, status, mode, position, scale, transform, adaptiveSync, ... }:
+  outputStr = { criteria, status, mode, position, scale, transform, adaptiveSync
+    , alias, ... }:
     ''output "${criteria}"'' + optionalString (status != null) " ${status}"
     + optionalString (mode != null) " mode ${mode}"
     + optionalString (position != null) " position ${position}"
     + optionalString (scale != null) " scale ${toString scale}"
     + optionalString (transform != null) " transform ${transform}"
     + optionalString (adaptiveSync != null)
-    " adaptive_sync ${if adaptiveSync then "on" else "off"}";
+    " adaptive_sync ${if adaptiveSync then "on" else "off"}"
+    + optionalString (alias != null) " alias \$${alias}";
 
   profileModule = types.submodule {
     options = {
@@ -296,6 +306,14 @@ in {
           message =
             "Cannot mix kanshi.settings with kanshi.profiles or kanshi.extraConfig";
         }
+        {
+          assertion = let profiles = filter (x: x ? profile) cfg.settings;
+          in length
+          (filter (x: any (a: a ? alias && a.alias != null) x.profile.outputs)
+            profiles) == 0;
+          message =
+            "Output kanshi.*.output.alias can only be defined on global scope";
+        }
       ];
     }
 
diff --git a/tests/modules/services/kanshi/alias-assertion.nix b/tests/modules/services/kanshi/alias-assertion.nix
new file mode 100644
index 000000000..0dc6d7e64
--- /dev/null
+++ b/tests/modules/services/kanshi/alias-assertion.nix
@@ -0,0 +1,18 @@
+{ config, pkgs, ... }: {
+  config = {
+    services.kanshi = {
+      enable = true;
+      package = config.lib.test.mkStubPackage { };
+      settings = [{
+        profile.name = "nomad";
+        profile.outputs = [{
+          criteria = "eDP-1";
+          alias = "test";
+        }];
+      }];
+    };
+
+    test.asserts.assertions.expected =
+      [ "Output kanshi.*.output.alias can only be defined on global scope" ];
+  };
+}
diff --git a/tests/modules/services/kanshi/default.nix b/tests/modules/services/kanshi/default.nix
index b7704b112..05e224aaa 100644
--- a/tests/modules/services/kanshi/default.nix
+++ b/tests/modules/services/kanshi/default.nix
@@ -1,4 +1,5 @@
 {
   kanshi-basic-configuration = ./basic-configuration.nix;
   kanshi-new-configuration = ./new-configuration.nix;
+  kanshi-alias-assertion = ./alias-assertion.nix;
 }
diff --git a/tests/modules/services/kanshi/new-configuration.conf b/tests/modules/services/kanshi/new-configuration.conf
index c0858a048..817f66329 100644
--- a/tests/modules/services/kanshi/new-configuration.conf
+++ b/tests/modules/services/kanshi/new-configuration.conf
@@ -1,12 +1,12 @@
 include "path/to/included/file"
-output "*" enable
+output "Iiyama North America PLE2483H-DP" alias $iiyama
 profile nomad {
   output "eDP-1" enable
 }
 
 profile desktop {
   output "eDP-1" disable
-  output "Iiyama North America PLE2483H-DP" enable position 0,0
+  output "$iiyama" enable position 0,0
   output "Iiyama North America PLE2483H-DP 1158765348486" enable mode 1920x1080 position 1920,0 scale 2.100000 transform flipped-270
   exec echo "1 two 3"
   exec echo "4 five 6"
diff --git a/tests/modules/services/kanshi/new-configuration.nix b/tests/modules/services/kanshi/new-configuration.nix
index 9b3a36478..2c92c730d 100644
--- a/tests/modules/services/kanshi/new-configuration.nix
+++ b/tests/modules/services/kanshi/new-configuration.nix
@@ -7,8 +7,8 @@
         { include = "path/to/included/file"; }
         {
           output = {
-            criteria = "*";
-            status = "enable";
+            criteria = "Iiyama North America PLE2483H-DP";
+            alias = "iiyama";
           };
         }
         {
@@ -27,7 +27,7 @@
               status = "disable";
             }
             {
-              criteria = "Iiyama North America PLE2483H-DP";
+              criteria = "$iiyama";
               status = "enable";
               position = "0,0";
             }