nixos/comma: init (#426405)

nixos/modules/module-list.nix

@@ -193,6 +193,7 @@
   ./programs/chrysalis.nix
   ./programs/clash-verge.nix
   ./programs/cnping.nix
+  ./programs/comma.nix
   ./programs/command-not-found/command-not-found.nix
   ./programs/coolercontrol.nix
   ./programs/corefreq.nix

nixos/modules/programs/comma.nix

@@ -0,0 +1,52 @@
+{
+  lib,
+  config,
+  pkgs,
+  ...
+}:
+
+let
+  cfg = config.programs.comma;
+in
+{
+  options.programs.comma = {
+    enable = lib.mkEnableOption "comma";
+    package = lib.mkPackageOption pkgs "comma" { };
+    enableBashIntegration = lib.mkEnableOption "comma command-not-found handler for bash" // {
+      default = true;
+    };
+    enableZshIntegration = lib.mkEnableOption "comma command-not-found handler for zsh" // {
+      default = true;
+    };
+    enableFishIntegration = lib.mkEnableOption "comma command-not-found handler for fish" // {
+      default = true;
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    environment.systemPackages = [ cfg.package ];
+    programs = {
+      bash.interactiveShellInit = lib.mkIf cfg.enableBashIntegration ''
+        source ${cfg.package}/share/comma/command-not-found.sh
+      '';
+      zsh.interactiveShellInit = lib.mkIf cfg.enableZshIntegration ''
+        source ${cfg.package}/share/comma/command-not-found.sh
+      '';
+      fish.interactiveShellInit = ''
+        source ${cfg.package}/share/comma/command-not-found.fish
+      '';
+
+      # Disable *other* command-not-found handlers
+      command-not-found.enable = lib.mkIf (
+        cfg.enableBashIntegration || cfg.enableZshIntegration || cfg.enableFishIntegration
+      ) (lib.mkDefault false);
+      nix-index = {
+        enableBashIntegration = lib.mkIf (cfg.enableBashIntegration) (lib.mkDefault false);
+        enableZshIntegration = lib.mkIf (cfg.enableZshIntegration) (lib.mkDefault false);
+        enableFishIntegration = lib.mkIf (cfg.enableFishIntegration) (lib.mkDefault false);
+      };
+    };
+  };
+
+  meta.maintainers = with lib.maintainers; [ pandapip1 ];
+}