modules/visuals: add highlight-undo

a plugin for highlighting undo/redo targets

modules/visuals/config.nix

@@ -118,5 +118,30 @@ in {
         }
       '';
     })
+
+    (mkIf cfg.highlight-undo.enable {
+      vim.startPlugins = ["highlight-undo"];
+      vim.luaConfigRC.fidget-nvim = nvim.dag.entryAnywhere ''
+        require('highlight-undo').setup({
+          duration = ${toString cfg.highlight-undo.duration},
+          highlight_for_count = ${boolToString cfg.highlight-undo.highlightForCount},
+          undo = {
+            hlgroup = ${cfg.highlight-undo.undo.hlGroup},
+            mode = 'n',
+            lhs = 'u',
+            map = 'undo',
+            opts = {}
+          },
+
+          redo = {
+            hlgroup = ${cfg.highlight-undo.redo.hlGroup},
+            mode = 'n',
+            lhs = '<C-r>',
+            map = 'redo',
+            opts = {}
+          },
+        })
+      '';
+    })
   ]);
 }

modules/visuals/visuals.nix

@@ -103,5 +103,40 @@ in {
         defaultText = literalExpression "config.vim.treesitter.enable";
       };
     };
+
+    highlight-undo = {
+      enable = mkEnableOption "highlight undo [highlight-undo]";
+
+      highlightForCount = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Enable support for highlighting when a `<count>` is provided before the key
+          If set to false it will only highlight when the mapping is not prefixed with a `<count>`
+        '';
+      };
+
+      duration = mkOption {
+        type = types.int;
+        description = "Duration of highlight";
+        default = 200;
+      };
+
+      undo = {
+        hlGroup = mkOption {
+          type = types.str;
+          description = "Highlight group for undo";
+          default = "HighlightUndo";
+        };
+      };
+
+      redo = {
+        hlGroup = mkOption {
+          type = types.str;
+          description = "Highlight group for redo";
+          default = "HighlightUndo";
+        };
+      };
+    };
   };
 }