home-manager/modules/programs/ncmpcpp.nix

{
  config,
  lib,
  pkgs,
  ...
}:
let
  inherit (lib)
    concatStringsSep
    literalExpression
    mkIf
    mkOption
    types
    ;

  cfg = config.programs.ncmpcpp;

  renderSettings = settings: concatStringsSep "\n" (lib.mapAttrsToList renderSetting settings);

  renderSetting = name: value: "${name}=${renderValue value}";

  renderValue =
    option:
    {
      int = toString option;
      bool = lib.hm.booleans.yesNo option;
      string = option;
    }
    .${builtins.typeOf option};

  renderBindings = bindings: concatStringsSep "\n" (map renderBinding bindings);

  renderBinding =
    { key, command }: concatStringsSep "\n  " ([ ''def_key "${key}"'' ] ++ maybeWrapList command);

  maybeWrapList = xs: if lib.isList xs then xs else [ xs ];

  valueType =
    with types;
    oneOf [
      bool
      int
      str
    ];

  bindingType = types.submodule {
    options = {
      key = mkOption {
        type = types.str;
        description = "Key to bind.";
        example = "j";
      };

      command = mkOption {
        type = with types; either str (listOf str);
        description = "Command or sequence of commands to be executed.";
        example = "scroll_down";
      };
    };
  };
in
{
  meta.maintainers = [ lib.hm.maintainers.olmokramer ];

  options.programs.ncmpcpp = {
    enable = lib.mkEnableOption "ncmpcpp - an ncurses Music Player Daemon (MPD) client";

    package = lib.mkPackageOption pkgs "ncmpcpp" {
      example = "pkgs.ncmpcpp.override { visualizerSupport = true; }";
    };

    mpdMusicDir = mkOption {
      type = with types; nullOr (coercedTo path toString str);
      default =
        let
          mpdCfg = config.services.mpd;
        in
        if pkgs.stdenv.hostPlatform.isLinux && mpdCfg.enable then mpdCfg.musicDirectory else null;
      defaultText = literalExpression ''
        if pkgs.stdenv.hostPlatform.isLinux && config.services.mpd.enable then
          config.services.mpd.musicDirectory
        else
          null
      '';
      description = ''
        Value of the `mpd_music_dir` setting. On Linux platforms the
        value of {var}`services.mpd.musicDirectory` is used as the
        default if {var}`services.mpd.enable` is
        `true`.
      '';
      example = "~/music";
    };

    settings = mkOption {
      type = types.attrsOf valueType;
      default = { };
      description = ''
        Attribute set from name of a setting to its value. For available options
        see
        {manpage}`ncmpcpp(1)`.
      '';
      example = {
        ncmpcpp_directory = "~/.local/share/ncmpcpp";
      };
    };

    bindings = mkOption {
      type = types.listOf bindingType;
      default = [ ];
      description = "List of keybindings.";
      example = literalExpression ''
        [
          { key = "j"; command = "scroll_down"; }
          { key = "k"; command = "scroll_up"; }
          { key = "J"; command = [ "select_item" "scroll_down" ]; }
          { key = "K"; command = [ "select_item" "scroll_up" ]; }
        ]
      '';
    };
  };

  config = mkIf cfg.enable {
    warnings = mkIf (cfg.settings ? mpd_music_dir && cfg.mpdMusicDir != null) [
      ("programs.ncmpcpp.settings.mpd_music_dir will be overridden by" + " programs.ncmpcpp.mpdMusicDir.")
    ];

    home.packages = [ cfg.package ];

    xdg.configFile = {
      "ncmpcpp/config" =
        let
          settings =
            cfg.settings
            // lib.optionalAttrs (cfg.mpdMusicDir != null) {
              mpd_music_dir = cfg.mpdMusicDir;
            };
        in
        mkIf (settings != { }) { text = renderSettings settings + "\n"; };

      "ncmpcpp/bindings" = mkIf (cfg.bindings != [ ]) {
        text = renderBindings cfg.bindings + "\n";
      };
    };
  };
}