plugins/completion: move to by-name

- Move nvim-cmp to plugins/cmp
- Move other completion plugins to plugins/by-name

plugins/by-name/lspkind/default.nix

@@ -0,0 +1,95 @@
+{
+  lib,
+  helpers,
+  config,
+  pkgs,
+  ...
+}:
+with lib;
+let
+  cfg = config.plugins.lspkind;
+in
+{
+  options.plugins.lspkind = helpers.neovim-plugin.extraOptionsOptions // {
+    enable = mkEnableOption "lspkind.nvim";
+
+    package = lib.mkPackageOption pkgs "lspkind" {
+      default = [
+        "vimPlugins"
+        "lspkind-nvim"
+      ];
+    };
+
+    mode = helpers.defaultNullOpts.mkEnum [
+      "text"
+      "text_symbol"
+      "symbol_text"
+      "symbol"
+    ] "symbol_text" "Defines how annotations are shown";
+
+    preset = helpers.defaultNullOpts.mkEnum [
+      "default"
+      "codicons"
+    ] "codicons" "Default symbol map";
+
+    symbolMap = helpers.mkNullOrOption (types.attrsOf types.str) "Override preset symbols";
+
+    cmp = {
+      enable = mkOption {
+        type = types.bool;
+        default = true;
+        description = "Integrate with nvim-cmp";
+      };
+
+      maxWidth = helpers.mkNullOrOption types.int "Maximum number of characters to show in the popup";
+
+      ellipsisChar = helpers.mkNullOrOption types.str "Character to show when the popup exceeds maxwidth";
+
+      menu = helpers.mkNullOrOption (types.attrsOf types.str) "Show source names in the popup";
+
+      after = helpers.mkNullOrOption types.str "Function to run after calculating the formatting. function(entry, vim_item, kind)";
+    };
+  };
+
+  config =
+    let
+      doCmp = cfg.cmp.enable && config.plugins.cmp.enable;
+      options =
+        {
+          inherit (cfg) mode preset;
+          symbol_map = cfg.symbolMap;
+        }
+        // (
+          if doCmp then
+            {
+              maxwidth = cfg.cmp.maxWidth;
+              ellipsis_char = cfg.cmp.ellipsisChar;
+              inherit (cfg.cmp) menu;
+            }
+          else
+            { }
+        )
+        // cfg.extraOptions;
+    in
+    mkIf cfg.enable {
+      extraPlugins = [ cfg.package ];
+
+      extraConfigLua = optionalString (!doCmp) ''
+        require('lspkind').init(${helpers.toLuaObject options})
+      '';
+
+      plugins.cmp.settings.formatting.format =
+        if cfg.cmp.after != null then
+          ''
+            function(entry, vim_item)
+              local kind = require('lspkind').cmp_format(${helpers.toLuaObject options})(entry, vim_item)
+
+              return (${cfg.cmp.after})(entry, vim_item, kind)
+            end
+          ''
+        else
+          ''
+            require('lspkind').cmp_format(${helpers.toLuaObject options})
+          '';
+    };
+}