{
  config,
  pkgs,
  lib,
  ...
}:
let
  inherit (builtins) attrNames;
  inherit (lib.meta) getExe;
  inherit (lib.options) mkEnableOption mkOption;
  inherit (lib.modules) mkIf mkMerge;
  inherit (lib.types) enum package listOf;
  inherit (lib.nvim.types) mkGrammarOption;
  inherit (lib.nvim.attrsets) mapListToAttrs;

  cfg = config.vim.languages.fish;

  defaultServers = [ "fish-lsp" ];
  servers = {
    fish-lsp = {
      cmd = [
        (getExe pkgs.fish-lsp)
        "start"
      ];
      filetypes = [ "fish" ];
      root_markers = [
        "config.fish"
        ".git"
      ];
    };
  };

  defaultFormat = [ "fish_indent" ];
  formats = {
    fish_indent = {
      package = pkgs.fish;
      config.command = "${cfg.format.package}/bin/fish_indent";
    };
  };
in
{
  options.vim.languages.fish = {
    enable = mkEnableOption "Fish language support";
    treesitter = {
      enable = mkEnableOption "Fish treesitter support" // {
        default = config.vim.languages.enableTreesitter;
      };
      package = mkGrammarOption pkgs "fish";
    };

    lsp = {
      enable = mkEnableOption "Fish LSP support" // {
        default = config.vim.lsp.enable;
      };
      servers = mkOption {
        type = listOf (enum (attrNames servers));
        default = defaultServers;
        description = "Fish LSP server to use";
      };
    };

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

      type = mkOption {
        type = listOf (enum (attrNames formats));
        default = defaultFormat;
        description = "Fish formatter to use";
      };

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

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

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

    (mkIf (cfg.format.enable && !cfg.lsp.enable) {
      vim.formatter.conform-nvim = {
        enable = true;
        setupOpts.formatters_by_ft.fish = cfg.format.type;
        setupOpts.formatters = mapListToAttrs (name: {
          inherit name;
          value = formats.${name};
        }) cfg.format.type;
      };
    })
  ]);
}