home-manager/modules/programs/readline.nix

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

with lib;

let

  cfg = config.programs.readline;

  mkSetVariableStr = n: v:
    let
      mkValueStr = v:
        if v == true then "on"
        else if v == false then "off"
        else if isInt v then toString v
        else if isString v then v
        else abort ("values ${toPretty v} is of unsupported type");
    in
      "set ${n} ${mkValueStr v}";

  mkBindingStr = k: v: "\"${k}\": ${v}";

in

{
  options.programs.readline = {
    enable = mkEnableOption "readline";

    bindings = mkOption {
      default = {};
      type = types.attrsOf types.str;
      example = literalExample ''
        { "\\C-h" = "backward-kill-word"; }
      '';
      description = "Readline bindings.";
    };

    variables = mkOption {
      type = with types; attrsOf (either str (either int bool));
      default = {};
      example = { expand-tilde = true; };
      description = ''
        Readline customization variable assignments.
      '';
    };

    includeSystemConfig = mkOption {
      type = types.bool;
      default = true;
      description = "Whether to include the system-wide configuration.";
    };

    extraConfig = mkOption {
      type = types.lines;
      default = "";
      description = ''
        Configuration lines appended unchanged to the end of the
        <filename>~/.inputrc</filename> file.
      '';
    };
  };

  config = mkIf cfg.enable {
    home.file.".inputrc".text =
      let
        configStr = concatStringsSep "\n" (
          optional cfg.includeSystemConfig "$include /etc/inputrc"
          ++ mapAttrsToList mkSetVariableStr cfg.variables
          ++ mapAttrsToList mkBindingStr cfg.bindings
        );
      in
        ''
          # Generated by Home Manager.

          ${configStr}
          ${cfg.extraConfig}
        '';
  };
}