{
  pkgs,
  config,
  lib,
  ...
}:
with lib;
with builtins; let
  format-env = pkgs.callPackage ./format_derivation.nix {inherit pkgs;};

  cfg = config.vim.languages.ruby;

  defaultServer = "rubyserver";
  servers = {
    rubyserver = {
      package = pkgs.rubyPackages_3_2.solargraph;
      lspConfig = ''
        lspconfig.solargraph.setup {
          on_attach = attach_keymaps,
          cmd = { "${cfg.lsp.package}/bin/solargraph", "stdio" }
        }
      '';
    };
  };

  # TODO: specify packages
  defaultFormat = "rubocop";
  formats = {
    rubocop = {
      package = format-env;
      nullConfig = ''
               lspconfig.rubocop.setup {
                on_attach = attach_keymaps,
                 cmd = { "${cfg.format.package}/bin/rubocop", "--lsp", "--require", "${cfg.format.package}/lib/ruby/gems/3.2.0/gems/rubocop-rails-2.20.2/lib/rubocop-rails.rb" }
               }
        --       local conditional = function(fn)
        --         local utils = require("null-ls.utils").make_conditional_utils()
        --         return fn(utils)
        --       end
        --
        --       table.insert(
        --         ls_sources,
        --          conditional(function(utils)
        --            return utils.root_has_file("Gemfile")
        --                    and null_ls.builtins.formatting.rubocop.with({
        --                        command = ",
        --                     args = vim.list_extend(
        --                         { "exec", "rubocop" },
        --                         nls.builtins.formatting.rubocop._opts.args
        --                       ),
        --                    })
        --                    or null_ls.builtins.formatting.rubocop.with({
        --                      command = "${cfg.format.package}/bin/rubocop",
        --                 })
        --          end)
        --       )
      '';
    };
  };
  # TODO: specify packages
  #  defaultDiagnostics = ["rubocop"];
  #  diagnostics = {
  #    rubocop = {
  #      package = pkgs.rubyPackages_3_2.rubocop;
  #      nullConfig = pkg: ''
  #        table.insert(
  #          ls_sources,
  #          null_ls.builtins.diagnostics.rubocop.with({
  #            command = "${lib.getExe pkg}",
  #          })
  #        )
  #      '';
  # };
  # };
in {
  options.vim.languages.ruby = {
    enable = mkEnableOption "Ruby/Ruby on Rails language support";

    treesitter = {
      enable = mkEnableOption "Enable Ruby treesitter" // {default = config.vim.languages.enableTreesitter;};
      rubyPackage = nvim.types.mkGrammarOption pkgs "ruby";
    };

    lsp = {
      enable = mkEnableOption "Enable Ruby/Ruby on Rails LSP support" // {default = config.vim.languages.enableLSP;};

      server = mkOption {
        description = "Ruby/RoR LSP server to use";
        type = with types; enum (attrNames servers);
        default = defaultServer;
      };

      package = mkOption {
        description = "Ruby/RoR LSP server package";
        type = types.package;
        default = servers.${cfg.lsp.server}.package;
      };
    };

    format = {
      enable = mkEnableOption "Enable Ruby/RoR formatting" // {default = config.vim.languages.enableFormat;};

      type = mkOption {
        description = "Ruby/RoR formatter to use";
        type = with types; enum (attrNames formats);
        default = defaultFormat;
      };

      package = mkOption {
        description = "Ruby/RoR formatter package";
        type = types.package;
        default = formats.${cfg.format.type}.package;
      };
    };

    #    extraDiagnostics = {
    # enable = mkEnableOption "Enable extra Ruby/RoR diagnostics" // {default = config.vim.languages.enableExtraDiagnostics;};

    #      types = lib.nvim.types.diagnostics {
    #        langDesc = "Ruby/RoR";
    #        inherit diagnostics;
    #        inherit defaultDiagnostics;
    #      };
    #    };
  };

  config = mkIf cfg.enable (mkMerge [
    (mkIf cfg.treesitter.enable {
      vim.treesitter.enable = true;
      vim.treesitter.grammars = [cfg.treesitter.rubyPackage];
    })

    (mkIf cfg.lsp.enable {
      vim.lsp.lspconfig.enable = true;
      vim.lsp.lspconfig.sources.ruby-lsp = servers.${cfg.lsp.server}.lspConfig;
    })

    (mkIf cfg.format.enable {
      vim.lsp.null-ls.enable = true;
      vim.lsp.null-ls.sources.ruby-format = formats.${cfg.format.type}.nullConfig;
    })

    #   (mkIf cfg.extraDiagnostics.enable {
    #     vim.lsp.null-ls.enable = true;
    #     vim.lsp.null-ls.sources = lib.nvim.languages.diagnosticsToLua {
    #       lang = "ruby";
    #       config = cfg.extraDiagnostics.types;
    #       inherit diagnostics;
    #     };
    #   })
  ]);
}