nixos/users/malte/kakoune.nix

{ pkgs, lib, config, ... }:

let
  # Configuration for kakoune plugins
  pluginConfigs = with pkgs.kakounePlugins; [
    { # FZF for kakoune
      pkg = fzf-kak;
      mappings = [{
        docstring = "FZF mode";
        mode = "user";
        key = "f";
        effect = ":fzf-mode<ret>";
      }];
      hooks = [{ # Change fzf settings before first use
        name = "ModuleLoaded";
        option = "fzf-file";
        commands = ''
          set-option global fzf_file_command "fd"
          set-option global fzf_highlight_command "bat"
        '';
      }];
    }

    { # Languange Server Config
      pkg = kak-lsp;
      config = ''
        eval %sh{kak-lsp --kakoune -s $kak_session}

        hook global WinSetOption filetype=rust %{
          hook window -group rust-inlay-hints BufReload .* rust-analyzer-inlay-hints
          hook window -group rust-inlay-hints NormalIdle .* rust-analyzer-inlay-hints
          hook window -group rust-inlay-hints InsertIdle .* rust-analyzer-inlay-hints
          hook -once -always window WinSetOption filetype=.* %{
            remove-hooks window rust-inlay-hints
          }
        }
      '';
      mappings = [{ # Enter LSP Usermode
        docstring = "LSP mode";
        mode = "user";
        key = "l";
        effect = ":enter-user-mode lsp<ret>";
      }];
      hooks = [{ # Start kak-lsp for specific windows
        name = "WinSetOption";
        commands = "lsp-enable-window";
        option = "filetype=(rust|nix|python|latex|typescript|javascript)";
      }];
    }

  ];

  additionalMappings = [{ # Switch to last buffer
    docstring = "Previous buffer";
    mode = "user";
    key = ",";
    effect = ":buffer-previous<ret>";
  }];

  additionalConfig = ''
    add-highlighter global/ number-lines -relative
    add-highlighter global/ wrap -word -indent

    # Do something about tabs..
    map global insert <tab> '    '
    hook global BufSetOption filetype=nix %{
      map buffer insert <tab> '  '
    }
  '';

  selectOr = attr: default: map (conf: conf.${attr} or default) pluginConfigs;
  selectList = attr: lib.flatten (selectOr attr [ ]);

in {

  programs.kakoune = {
    enable = true;

    config = {
      colorScheme = "gruvbox-dark";
      ui.enableMouse = true;

      hooks = selectList "hooks";

      keyMappings = (selectList "mappings") ++ additionalMappings;
    };

    extraConfig = (toString (selectOr "config" "")) + additionalConfig;

    plugins = map (conf: conf.pkg) pluginConfigs;
  };

  home.packages = with pkgs; [
    # For Nix
    rnix-lsp
    # For Rust
    rust-analyzer-nightly
    # For Python
    python3.pkgs.python-lsp-server
    # For TypeScript
    nodePackages.typescript
    nodePackages.typescript-language-server
    # For JavaScript
    flow
  ];

  xdg.configFile."kak-lsp/kak-lsp.toml".text = ''
    [language.rust]
    filetypes = ["rust"]
    roots = ["Cargo.toml"]
    command = "${pkgs.rust-analyzer-nightly}/bin/rust-analyzer"
    settings_section = "rust-analyzer"

    [language.rust.settings.rust-analyzer]
    hoverActions.enable = true # kak-lsp doesn't support this at the moment
    procMacro.enable = true
    cargo.loadOutDirsFromCheck = true

    [language.nix]
    filetypes = ["nix"]
    roots = ["flake.nix", "shell.nix", ".git", ".hg"]
    command = "${pkgs.rnix-lsp}/bin/rnix-lsp"

    [language.python]
    filetypes = ["python"]
    roots = ["requirements.txt", "setup.py", ".git", ".hg"]
    command = "${pkgs.python3.pkgs.python-lsp-server}/bin/pylsp"
    settings_section = "pylsp"

    [language.python.settings.pylsp]
    pylsp.configurationSources = ["flake8"]

    [language.latex]
    filetypes = ["latex"]
    roots = [".git", ".hg"]
    command = "${pkgs.texlab}/bin/texlab"
    settings_section = "texlab"
    [language.latex.settings.texlab]
    # See https://github.com/latex-lsp/texlab/blob/master/docs/options.md
    #
    # Preview configuration for zathura with SyncTeX search.
    # For other PDF viewers see https://github.com/latex-lsp/texlab/blob/master/docs/previewing.md
    forwardSearch.executable = "${pkgs.zathura}/bin/zathura"
    forwardSearch.args = [
        "%p",
        "--synctex-forward", # Support texlab-forward-search
        "%l:1:%f",
        "--synctex-editor-command", # use Control+Left-Mouse-Button to jump to source.
        """
            sh -c '
                echo "
                    evaluate-commands -client $kak_client %{
                        evaluate-commands -try-client %opt{jumpclient} %{
                            edit -- %{input} %{line}
                        }
                    }
                " | kak -p $kak_session
            '
        """,
    ]

    [language.typescript]
    filetypes = ["typescript"]
    roots = ["package.json", "tsconfig.json", ".git", ".hg"]
    command = "${pkgs.nodePackages.typescript-language-server}/bin/typescript-language-server"
    args = [
      "--stdio",
      "--tsserver-path=${pkgs.nodePackages.typescript}/lib/node_modules/typescript/lib"
    ]

    [language.javascript]
    filetypes = ["javascript"]
    roots = [".flowconfig"]
    command = "${pkgs.flow}/bin/flow"
    args = ["lsp"]

    # Semantic tokens support
    [[semantic_tokens]]
    token = "comment"
    face = "documentation"
    modifiers = ["documentation"]

    [[semantic_tokens]]
    token = "comment"
    face = "comment"

    [[semantic_tokens]]
    token = "function"
    face = "function"

    [[semantic_tokens]]
    token = "keyword"
    face = "keyword"

    [[semantic_tokens]]
    token = "namespace"
    face = "module"

    [[semantic_tokens]]
    token = "operator"
    face = "operator"

    [[semantic_tokens]]
    token = "string"
    face = "string"

    [[semantic_tokens]]
    token = "type"
    face = "type"

    [[semantic_tokens]]
    token = "variable"
    face = "default+d"
    modifiers = ["readonly"]

    [[semantic_tokens]]
    token = "variable"
    face = "default+d"
    modifiers = ["constant"]

    [[semantic_tokens]]
    token = "variable"
    face = "variable"
  '';

  systemd.user.sessionVariables = {
    EDITOR = "${pkgs.kakoune}/bin/kak";
    VISUAL = "${pkgs.kitty}/bin/kitty ${pkgs.kakoune}/bin/kak";
  };
  pam.sessionVariables = {
    EDITOR = config.systemd.user.sessionVariables.EDITOR;
  };
}