nichts/modules/wms/wayland/hyprland/nixos-module.nix

{
  config,
  lib,
  pkgs,
  ...
}: let
  cfg = config.programs.hyprland;

  toHyprconf = {
    attrs,
    indentLevel ? 0,
    importantPrefixes ? ["$"],
  }: let
    inherit
      (lib)
      all
      concatMapStringsSep
      concatStrings
      concatStringsSep
      filterAttrs
      foldl
      generators
      hasPrefix
      isAttrs
      isList
      mapAttrsToList
      replicate
      ;

    initialIndent = concatStrings (replicate indentLevel "  ");

    toHyprconf' = indent: attrs: let
      sections =
        filterAttrs (n: v: isAttrs v || (isList v && all isAttrs v)) attrs;

      mkSection = n: attrs:
        if lib.isList attrs
        then (concatMapStringsSep "\n" (a: mkSection n a) attrs)
        else ''
          ${indent}${n} {
          ${toHyprconf' "  ${indent}" attrs}${indent}}
        '';

      mkFields = generators.toKeyValue {
        listsAsDuplicateKeys = true;
        inherit indent;
      };

      allFields =
        filterAttrs (n: v: !(isAttrs v || (isList v && all isAttrs v)))
        attrs;

      isImportantField = n: _:
        foldl (acc: prev:
          if hasPrefix prev n
          then true
          else acc)
        false
        importantPrefixes;

      importantFields = filterAttrs isImportantField allFields;

      fields =
        builtins.removeAttrs allFields
        (mapAttrsToList (n: _: n) importantFields);
    in
      mkFields importantFields
      + concatStringsSep "\n" (mapAttrsToList mkSection sections)
      + mkFields fields;
  in
    toHyprconf' initialIndent attrs;
in {
  options.programs.hyprland = {
    plugins = lib.mkOption {
      type = with lib.types; listOf (either package path);
      default = [];
      description = ''
        List of Hyprland plugins to use. Can either be packages or
        absolute plugin paths.
      '';
    };

    settings = lib.mkOption {
      type = with lib.types; let
        valueType =
          nullOr (oneOf [
            bool
            int
            float
            str
            path
            (attrsOf valueType)
            (listOf valueType)
          ])
          // {
            description = "Hyprland configuration value";
          };
      in
        valueType;
      default = {};
      description = ''
        Hyprland configuration written in Nix. Entries with the same key
        should be written as lists. Variables' and colors' names should be
        quoted. See <https://wiki.hyprland.org> for more examples.

        ::: {.note}
        Use the [](#opt-wayland.windowManager.hyprland.plugins) option to
        declare plugins.
        :::

      '';
      example = lib.literalExpression ''
        {
          decoration = {
            shadow_offset = "0 5";
            "col.shadow" = "rgba(00000099)";
          };

          "$mod" = "SUPER";

          bindm = [
            # mouse movements
            "$mod, mouse:272, movewindow"
            "$mod, mouse:273, resizewindow"
            "$mod ALT, mouse:272, resizewindow"
          ];
        }
      '';
    };

    extraConfig = lib.mkOption {
      type = lib.types.lines;
      default = "";
      example = ''
        # window resize
        bind = $mod, S, submap, resize

        submap = resize
        binde = , right, resizeactive, 10 0
        binde = , left, resizeactive, -10 0
        binde = , up, resizeactive, 0 -10
        binde = , down, resizeactive, 0 10
        bind = , escape, submap, reset
        submap = reset
      '';
      description = ''
        Extra configuration lines to add to `~/.config/hypr/hyprland.conf`.
      '';
    };

    sourceFirst =
      lib.mkEnableOption ''
        putting source entries at the top of the configuration
      ''
      // {
        default = true;
      };

    importantPrefixes = lib.mkOption {
      type = with lib.types; listOf str;
      default =
        ["$" "bezier" "name"]
        ++ lib.optionals cfg.sourceFirst ["source"];
      example = ["$" "bezier"];
      description = ''
        List of prefix of attributes to source at the top of the config.
      '';
    };
  };
  config = lib.mkIf cfg.enable {
    environment.systemPackages = lib.concatLists [
      (lib.optional (cfg.package != null) cfg.package)
      (lib.optional (cfg.xwayland.enable) pkgs.xwayland)
    ];
    environment.etc."xdg/hypr/hyprland.conf" = let
      shouldGenerate = cfg.extraConfig != "" || cfg.settings != {} || cfg.plugins != [];

      pluginsToHyprconf = plugins:
        toHyprconf {
          attrs = {
            plugin = let
              mkEntry = entry:
                if lib.types.package.check entry
                then "${entry}/lib/lib${entry.pname}.so"
                else entry;
            in
              map mkEntry cfg.plugins;
          };
          inherit (cfg) importantPrefixes;
        };
    in
      lib.mkIf shouldGenerate {
        text =
          lib.optionalString (cfg.plugins != [])
          (pluginsToHyprconf cfg.plugins)
          + lib.optionalString (cfg.settings != {})
          (toHyprconf {
            attrs = cfg.settings;
            inherit (cfg) importantPrefixes;
          })
          + lib.optionalString (cfg.extraConfig != "") cfg.extraConfig;
      };
  };
}