OSShells, refactor shells to single option

nixosModules/apps/shells/app.nix

@@ -1,9 +1,29 @@
-{ ... }:
+{ config, pkgs, lib, ... }: let
+  fs = lib.fileset;
+  shellFilter = {name, ...}: name == "shell.nix";
+  shellImports = fs.toList (fs.fileFilter shellFilter ./.);
+  shellNames = map (
+    path: let
+      splitPath = lib.strings.splitString "/" path;
+      splitPathLen = builtins.length splitPath;
+    in builtins.elemAt splitPath (splitPathLen - 2)
+  ) shellImports;
+in {
+  imports = shellImports;
 
-{
-  imports = [
-    ./fish
-    ./xonsh
-    ./zsh
-  ];
+  options.shell = let 
+    shellNameEnum = lib.types.enum shellNames;
+  in {
+    defaultShell = lib.mkOption {
+      type = shellNameEnum;
+    };
+    enabledShells = lib.mkOption {
+      type = lib.types.listOf shellNameEnum;
+    };
+  };
+
+  config = {
+    users.defaultUserShell = pkgs."${config.shell.defaultShell}";
+    environment.shells = map (shell: pkgs."${shell}") config.shell.enabledShells;
+  };
 }

nixosModules/apps/shells/fish/default.nix

@@ -1,15 +0,0 @@
-{ config, pkgs, lib, ... }:
-
-{
-  options = {
-    fish.enable = lib.mkEnableOption "Enables fish";
-    fish.setDefault = lib.mkEnableOption
-      "Sets fish as the default user's shell";
-  };
-
-  config = lib.mkIf config.fish.enable {
-    programs.fish.enable = true;
-    users.defaultUserShell = lib.mkIf config.fish.setDefault pkgs.fish;
-    environment.shells = with pkgs; [ fish ];
-  };
-}

nixosModules/apps/shells/fish/shell.nix

@@ -0,0 +1,7 @@
+{ config, lib, ... }:
+
+{
+  config = lib.mkIf (config.shell.defaultShell == "fish") {
+    programs.fish.enable = true;
+  };
+}

nixosModules/apps/shells/xonsh/default.nix

@@ -1,15 +0,0 @@
-{ config, pkgs, lib, ... }:
-
-{
-  options = {
-    xonsh.enable = lib.mkEnableOption "Enables xonsh";
-    xonsh.setDefault = lib.mkEnableOption
-      "Sets xonsh as the default user's shell";
-  };
-
-  config = lib.mkIf config.xonsh.enable {
-    programs.xonsh.enable = true;
-    users.defaultUserShell = lib.mkIf config.xonsh.setDefault pkgs.xonsh;
-    environment.shells = with pkgs; [ xonsh ];
-  };
-}

nixosModules/apps/shells/xonsh/shell.nix

@@ -0,0 +1,7 @@
+{ config, lib, ... }:
+
+{
+  config = lib.mkIf (config.shell.defaultShell == "xonsh") {
+    programs.xonsh.enable = true;
+  };
+}

nixosModules/apps/shells/zsh/default.nix

@@ -1,20 +0,0 @@
-{ config, pkgs, lib, ... }:
-
-{
-  options = {
-    zsh.enable = lib.mkEnableOption "Enables zsh";
-    zsh.setDefault = lib.mkEnableOption "Sets zsh as the default user's shell";
-  };
-
-  config = lib.mkIf config.zsh.enable {
-    programs.zsh = {
-      enable = true;
-      enableCompletion = true;
-      autosuggestions.enable = true;
-      histFile = "$HOME/.config/zsh/history";
-      histSize = 2000;
-    };
-    users.defaultUserShell = lib.mkIf config.zsh.setDefault pkgs.zsh;
-    environment.shells = with pkgs; [ zsh ];
-  };
-}

nixosModules/apps/shells/zsh/shell.nix

@@ -0,0 +1,13 @@
+{ config, lib, ... }:
+
+{
+  config = lib.mkIf (config.shell.defaultShell == "zsh") {
+    programs.zsh = {
+      enable = true;
+      enableCompletion = true;
+      autosuggestions.enable = true;
+      histFile = "$HOME/.config/zsh/history";
+      histSize = 2000;
+    };
+  };
+}