{
  config,
  pkgs,
  lib,
  ...
}: let
  inherit (builtins) attrNames;
  inherit (lib.generators) mkLuaInline;
  inherit (lib.options) mkEnableOption mkOption;
  inherit (lib.modules) mkIf mkMerge;
  inherit (lib.lists) elem;
  inherit (lib.meta) getExe;
  inherit (lib.types) enum package bool;
  inherit (lib.nvim.attrsets) mapListToAttrs;
  inherit (lib.nvim.lua) toLuaObject;
  inherit (lib.nvim.types) mkGrammarOption diagnostics mkPluginSetupOption mkServersOption;
  inherit (lib.nvim.dag) entryAnywhere entryBefore;

  cfg = config.vim.languages.ts;

  defaultServers = ["ts_ls"];
  servers = {
    ts_ls = {
      enable = true;
      cmd = [(getExe pkgs.typescript-language-server) "--stdio"];
      filetypes = ["javascript" "javascriptreact" "javascript.jsx" "typescript" "typescriptreact" "typescript.tsx"];
      root_markers = ["tsconfig.json" "jsconfig.json" "package.json" ".git"];
      on_attach =
        mkLuaInline
        /*
        lua
        */
        ''
          function(client, bufnr)
            attach_keymaps(client, bufnr);
            client.server_capabilities.documentFormattingProvider = false;
          end
        '';
    };

    denols = {
      enable = true;
      cmd = [(getExe pkgs.deno) "lsp"];
      package = pkgs.deno;
      filetypes = ["javascript" "javascriptreact" "javascript.jsx" "typescript" "typescriptreact" "typescript.tsx"];
      root_markers = ["tsconfig.json" "jsconfig.json" "package.json" ".git"];
      on_attach =
        mkLuaInline
        /*
        lua
        */
        "attach_keymaps";
    };

    # Here for backwards compatibility. Still consider tsserver a valid
    # configuration in the enum, but assert if it's set to *properly*
    # redirect the user to the correct server.
    tsserver = {
      enable = true;
      cmd = [(getExe pkgs.typescript-language-server) "--stdio"];
      package = pkgs.typescript-language-server;
      filetypes = ["javascript" "javascriptreact" "javascript.jsx" "typescript" "typescriptreact" "typescript.tsx"];
      root_markers = ["tsconfig.json" "jsconfig.json" "package.json" ".git"];
      on_attach =
        mkLuaInline
        /*
        lua
        */
        "attach_keymaps";
    };
  };

  # TODO: specify packages
  defaultFormat = "prettier";
  formats = {
    prettier = {
      package = pkgs.prettier;
    };

    prettierd = {
      package = pkgs.prettierd;
    };

    biome = {
      package = pkgs.biome;
    };
  };

  # TODO: specify packages
  defaultDiagnosticsProvider = ["eslint_d"];
  diagnosticsProviders = {
    eslint_d = let
      pkg = pkgs.eslint_d;
    in {
      package = pkg;
      config = {
        cmd = getExe pkg;
        required_files = [
          "eslint.config.js"
          "eslint.config.mjs"
          ".eslintrc"
          ".eslintrc.cjs"
          ".eslintrc.json"
          ".eslintrc.js"
          ".eslintrc.yml"
        ];
      };
    };
  };
in {
  _file = ./ts.nix;
  options.vim.languages.ts = {
    enable = mkEnableOption "Typescript/Javascript language support";

    treesitter = {
      enable = mkEnableOption "Typescript/Javascript treesitter" // {default = config.vim.languages.enableTreesitter;};
      tsPackage = mkGrammarOption pkgs "tsx";
      jsPackage = mkGrammarOption pkgs "javascript";
    };

    lsp = {
      enable = mkEnableOption "Typescript/Javascript LSP support" // {default = config.vim.lsp.enable;};
      servers = mkServersOption "Typescript/Javascript" servers defaultServers;
    };

    format = {
      enable = mkEnableOption "Typescript/Javascript formatting" // {default = config.vim.languages.enableFormat;};

      type = mkOption {
        description = "Typescript/Javascript formatter to use";
        type = enum (attrNames formats);
        default = defaultFormat;
      };

      package = mkOption {
        description = "Typescript/Javascript formatter package";
        type = package;
        default = formats.${cfg.format.type}.package;
      };
    };

    extraDiagnostics = {
      enable = mkEnableOption "extra Typescript/Javascript diagnostics" // {default = config.vim.languages.enableExtraDiagnostics;};

      types = diagnostics {
        langDesc = "Typescript/Javascript";
        inherit diagnosticsProviders;
        inherit defaultDiagnosticsProvider;
      };
    };

    extensions = {
      ts-error-translator = {
        enable = mkEnableOption ''
          [ts-error-translator.nvim]: https://github.com/dmmulroy/ts-error-translator.nvim

          Typescript error translation with [ts-error-translator.nvim]

        '';

        setupOpts = mkPluginSetupOption "ts-error-translator" {
          # This is the default configuration behaviour.
          auto_override_publish_diagnostics = mkOption {
            description = "Automatically override the publish_diagnostics handler";
            type = bool;
            default = true;
          };
        };
      };
    };
  };

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

    (mkIf cfg.lsp.enable {
      vim.lsp.servers =
        mapListToAttrs (n: {
          name = n;
          value = servers.${n};
        })
        cfg.lsp.servers;
    })

    (mkIf (cfg.lsp.enable && elem "denols" cfg.lsp.servers) {
      vim.luaConfigRC.denols =
        entryBefore ["lsp-servers"]
        /*
        lua
        */
        ''
          vim.g.markdown_fenced_languages = { "ts=typescript" }
        '';
    })

    (mkIf cfg.format.enable {
      vim.formatter.conform-nvim = {
        enable = true;
        setupOpts = {
          formatters_by_ft.typescript = [cfg.format.type];
          # .tsx files
          formatters_by_ft.typescriptreact = [cfg.format.type];
          formatters.${cfg.format.type} = {
            command = getExe cfg.format.package;
          };
        };
      };
    })

    (mkIf cfg.extraDiagnostics.enable {
      vim.diagnostics.nvim-lint = {
        enable = true;
        linters_by_ft.typescript = cfg.extraDiagnostics.types;
        linters_by_ft.typescriptreact = cfg.extraDiagnostics.types;

        linters =
          mkMerge (map (name: {${name} = diagnosticsProviders.${name}.config;})
            cfg.extraDiagnostics.types);
      };
    })

    # Extensions
    (mkIf cfg.extensions."ts-error-translator".enable {
      vim.startPlugins = ["ts-error-translator-nvim"];
      vim.pluginRC.ts-error-translator = entryAnywhere ''
        require("ts-error-translator").setup(${toLuaObject cfg.extensions.ts-error-translator.setupOpts})
      '';
    })

    # Warn the user if they have set the default server name to tsserver to match upstream (us)
    # The name "tsserver" has been deprecated in lspconfig, and now should be called ts_ls. This
    # is a purely cosmetic change, but emits a warning if not accounted for.
    {
      assertions = [
        {
          assertion = cfg.lsp.enable -> cfg.lsp.server != "tsserver";
          message = ''
            As of a recent lspconfig update, the `tsserver` configuration has been renamed
            to `ts_ls` to match upstream behaviour of `lspconfig`, and the name `tsserver`
            is no longer considered valid by nvf. Please set `vim.languages.ts.lsp.server`
            to `"ts_ls"` instead of to `${cfg.lsp.server}`

            Please see <https://github.com/neovim/nvim-lspconfig/pull/3232> for more details
            about this change.
          '';
        }
      ];
    }
  ]);
}