lsp/lightbulb: cleanup; modularize autocommand behaviour

modules/plugins/lsp/lightbulb/config.nix

@@ -4,6 +4,7 @@
   ...
 }: let
   inherit (lib.modules) mkIf;
+  inherit (lib.strings) optionalString;
   inherit (lib.nvim.dag) entryAnywhere;
   inherit (lib.nvim.lua) toLuaObject;
 
@@ -12,13 +13,29 @@ in {
   config = mkIf (cfg.enable && cfg.lightbulb.enable) {
     vim = {
       startPlugins = ["nvim-lightbulb"];
-
       pluginRC.lightbulb = entryAnywhere ''
-        vim.api.nvim_command('autocmd CursorHold,CursorHoldI * lua require\'nvim-lightbulb\'.update_lightbulb()')
-
-        -- Enable trouble diagnostics viewer
-        require'nvim-lightbulb'.setup(${toLuaObject cfg.lightbulb.setupOpts})
+        local nvim_lightbulb = require("nvim-lightbulb")
+        nvim_lightbulb.setup(${toLuaObject cfg.lightbulb.setupOpts})
+        ${optionalString cfg.lightbulb.autocmd.enable ''
+          vim.api.nvim_create_autocmd(${toLuaObject cfg.lightbulb.autocmd.events}, {
+            pattern = ${toLuaObject cfg.lightbulb.autocmd.pattern},
+            callback = function()
+              nvim_lightbulb.update_lightbulb()
+            end,
+          })
+        ''}
       '';
     };
+
+    warnings = [
+      # This could have been an assertion, but the chances of collision is very low and asserting here
+      # might be too dramatic. Let's only warn the user, *in case* this occurs and is not intended. No
+      # error will be thrown if 'lightbulb.setupOpts.autocmd.enable' has not been set by the user.
+      (mkIf (cfg.lightbulb.autocmd.enable -> (cfg.lightbulb.setupOpts.autocmd.enabled or false)) ''
+        Both 'vim.lsp.lightbulb.autocmd.enable' and 'vim.lsp.lightbulb.setupOpts.autocmd.enable' are set
+        simultaneously. This might have performance implications due to frequent updates. Please set only
+        one option to handle nvim-lightbulb autocmd.
+      '')
+    ];
   };
 }