nixos-config/modules/helix/default.nix

{ pkgs, ... }:
let
  hx-pretty = pkgs.writeShellScript "hx-pretty.sh" ''
    exec prettier --stdin-filepath "$HX_FILE"
  '';

  prettier-formats = map
    (name: {
      inherit name;
      auto-format = true;
      indent = { tab-width = 4; unit = "\t"; };
      formatter.command = hx-pretty;
    })
    [
      "css"
      "html"
      "javascript"
      "typescript"
    ];

in
{
  environment.etc."bck-helix/config.toml".source =
    (pkgs.formats.toml { }).generate "config.toml" {
      theme = "dark_plus";
      editor = {
        auto-format = true;
        bufferline = "multiple";
        indent-guides.render = true;
        line-number = "relative";
        mouse = false;
        scrolloff = 10;
        true-color = true;
      };
      keys = {
        normal.A-j = ":buffer-previous";
        normal.A-k = ":buffer-next";
        normal.space.e = ":w";
        normal.space.backspace = ":reset-diff-change";
      };
    };

  environment.etc."bck-helix/languages.toml".source =
    (pkgs.formats.toml { }).generate "languages.toml" {
      language = prettier-formats ++ [
        {
          name = "bash";
          auto-format = true;
          indent = { tab-width = 4; unit = "\t"; };
        }
        {
          name = "lua";
          auto-format = true;
          indent = { tab-width = 4; unit = "\t"; };
        }
        {
          name = "nix";
          auto-format = true;
          formatter.command = "nixpkgs-fmt";
        }
        {
          name = "python";
          auto-format = true;
          language-servers = [ "pyright" ];
          formatter = { command = "black"; args = [ "--quiet" "-" ]; };
        }
        {
          name = "yaml";
          auto-format = true;
          formatter.command = hx-pretty;
        }
      ];
      language-server = {
        pyright = {
          command = "pyright-langserver";
          args = [ "--stdio" ];
        };
      };
    };

  environment.systemPackages = with pkgs; [
    (helix.overrideAttrs ({ patches ? [ ], ... }: {
      # Patch required for .editorconfig to work properly with formatters
      patches = patches ++ [ ./format-filepath.patch ];
      postPatch = ''
        sed 's/tab-width = .,/tab-width = 4,/' -i languages.toml
      '';
    }))
  ];

  environment.etc."bck-settings.sh".text = ''
    mkdir -p ~/.config && ln -nTfs /etc/bck-helix ~/.config/helix
  '';
}