programs.rio: add module (#4118)

Adds a programs.rio module to control Rio installation and configuration, a gpu accelerated terminal

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>

modules/programs/rio.nix

@@ -0,0 +1,52 @@
+{ lib, pkgs, config, ... }:
+let
+  cfg = config.programs.rio;
+
+  settingsFormat = pkgs.formats.toml { };
+
+  inherit (pkgs.stdenv.hostPlatform) isDarwin;
+in {
+  options.programs.rio = {
+    enable = lib.mkEnableOption null // {
+      description = lib.mdDoc ''
+        Enable Rio, a terminal built to run everywhere, as a native desktop applications by
+        Rust/WebGPU or even in the browsers powered by WebAssembly/WebGPU.
+      '';
+    };
+
+    package = lib.mkPackageOption pkgs "rio" { };
+
+    settings = lib.mkOption {
+      type = settingsFormat.type;
+      default = { };
+      description = ''
+        Configuration written to <filename>$XDG_CONFIG_HOME/rio/config.toml</filename> on Linux or
+        <filename>$HOME/Library/Application Support/rio/config.toml</filename> on Darwin. See
+        <link xlink:href="https://raphamorim.io/rio/docs/#configuration-file"/> for options.
+      '';
+    };
+  };
+  meta.maintainers = [ lib.maintainers.otavio ];
+
+  config = lib.mkIf cfg.enable (lib.mkMerge [
+    {
+      home.packages = [ cfg.package ];
+    }
+
+    # Only manage configuration if not empty
+    (lib.mkIf (cfg.settings != { } && !isDarwin) {
+      xdg.configFile."rio/config.toml".source = if lib.isPath cfg.settings then
+        cfg.settings
+      else
+        settingsFormat.generate "rio.toml" cfg.settings;
+    })
+
+    (lib.mkIf (cfg.settings != { } && isDarwin) {
+      home.file."Library/Application Support/rio/config.toml".source =
+        if lib.isPath cfg.settings then
+          cfg.settings
+        else
+          settingsFormat.generate "rio.toml" cfg.settings;
+    })
+  ]);
+}