pistol: add module

modules/programs/pistol.nix

@@ -0,0 +1,49 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.programs.pistol;
+
+  configFile =
+    concatStringsSep "\n" (mapAttrsToList (k: v: "${k} ${v}") cfg.config);
+
+in {
+  meta.maintainers = [ hm.maintainers.mtoohey ];
+
+  options.programs.pistol = {
+    enable = mkEnableOption ''
+      Pistol, a general purpose file previewer designed for terminal file
+      managers'';
+
+    config = mkOption {
+      type = with types; attrsOf str;
+      default = { };
+      example = literalExpression ''
+        {
+          "text/*" = "bat --paging=never --color=always %pistol-filename%";
+          "inode/directory" = "ls -l --color %pistol-filename%";
+        }
+      '';
+      description = ''
+        Pistol configuration written to
+        <filename>$XDG_CONFIG_HOME/pistol/pistol.conf</filename>.
+      '';
+    };
+
+  };
+
+  config = mkIf cfg.enable (mkMerge [
+    { home.packages = [ pkgs.pistol ]; }
+
+    (mkIf (cfg.config != { } && pkgs.stdenv.hostPlatform.isDarwin) {
+      home.file."Library/Application Support/pistol/pistol.conf".text =
+        configFile;
+    })
+
+    (mkIf (cfg.config != { } && !pkgs.stdenv.hostPlatform.isDarwin) {
+      xdg.configFile."pistol/pistol.conf".text = configFile;
+    })
+  ]);
+}