nvf/modules/plugins/languages/beancount.nix

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

  cfg = config.vim.languages.beancount;

  # Wrap the language server to ensure 'bean-check' and 'bean-format'
  # from 'pkgs.beancount' are in the PATH when the server runs.
  beancountLanguageServerWrapped = pkgs.writeShellScriptBin
    "beancount-language-server"
    ''
      export PATH=$PATH:${pkgs.beancount}/bin
      exec ${pkgs.beancount-language-server}/bin/beancount-language-server "$@"
    '';

  defaultServers = "beancount-language-server";
  servers = {
    beancount-language-server = {
      rootmarkers = [".git"];
      filetypes = ["beancount" "bean"];
      cmd = ["${beancountLanguageServerWrapped}/bin/beancount-language-server"];
    };
  };

  defaultFormat = "bean-format";
  formats = {
    bean-format = {
      package = pkgs.beancount;
    };
  };
in {
  options.vim.languages.beancount = {
    enable = mkEnableOption "Beancount language support";

    treesitter = {
      enable = mkEnableOption "Beancount treesitter support" // {default = config.vim.languages.enableTreesitter;};
      package = mkGrammarOption pkgs "beancount";
    };

    lsp = {
      enable = mkEnableOption "Beancount LSP support" // {default = config.vim.lsp.enable;};

      servers = mkOption {
        type = singleOrListOf (enum (attrNames servers));
        default = defaultServers;
        description = "Beancount LSP server to use.";
      };
    };

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

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

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

  config = mkIf cfg.enable (mkMerge [
    (mkIf cfg.treesitter.enable {
      vim.treesitter.enable = true;
      vim.treesitter.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 {
      vim.formatter.conform-nvim = {
        enable = true;
        setupOpts = {
          formatters_by_ft.beancount = [cfg.format.type];
          formatters.${cfg.format.type} = {
            command = getExe' cfg.format.package cfg.format.type;
          };
        };
      };
    })
  ]);
}