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

with lib;
with types;
let
  # Functions for internal use {{{
  generateOption = name: value:
    if isBool value
    then "OPTIONS=${if value then "" else "!"}${name}"
    else "OPTIONS=${name}:${toString value}";

  generateHilite = field: settings:
    let createHiliteString = trigger: color: "/${trigger}/${color}";
        hilite_strings = mapAttrsToList createHiliteString settings;
    in "OPTIONS=hilite_status:${field}${concatStrings hilite_strings}";

  generateMsgType = action: messages:
    let createMsgTypeString = message: ''MSGTYPE=${action} "${message}"'';
        msg_type_strings = map createMsgTypeString messages;
    in concatStringsSep "\n" msg_type_strings;

  generateMenuColor = regex: color: ''MENUCOLOR="${regex}"=${color}'';
  # }}}

  # Generate base configuration {{{
  generateConfig = { nethack_options, hilite_status, msg_types, menu_colors, ... } @ config:
    let all_configs = (mapAttrsToList generateOption nethack_options)
                   ++ (mapAttrsToList generateHilite hilite_status)
                   ++ (mapAttrsToList generateMsgType msg_types)
                   ++ (mapAttrsToList generateMenuColor menu_colors);
    in concatStringsSep "\n" all_configs;
  # }}}

  # Generate choose options {{{
  generateChoose = choose_config:
    if choose_config == {} then "" else
    let generateChooseOption = name: config: "[${name}]\n" + generateConfig config;
        choose_options = mapAttrsToList (n: v: generateChooseOption n v) choose_config;
        choose_names = concatStringsSep "," (attrNames choose_config);
    in "CHOOSE=${choose_names}\n${concatStringsSep "\n" choose_options}";
  # }}}

  # Generate whole .nethackrc {{{
  generateNethackrc = nethack_config:
    let base_config = generateConfig nethack_config;
        choose_config = generateChoose nethack_config.choose_options;
    in base_config + "\n" + choose_config;
  # }}}
in
{
  # Options definitions {{{
  options.programs.nethack = {
    enable = mkEnableOption "nethack configuration";

    package = mkOption {
      type = types.package;
      default = pkgs.nethack;
      description = "Nethack package to install";
    };

    nethack_options = mkOption {
      type = attrsOf (oneOf [bool int str]);
      default = {};
      description = "Nethack options";
      example = literalExpression ''
        {
          boulder = "0";
          windowtype = "curses";
          statuslines = 3;
          autopickup = true;
        }
      '';
    };

    hilite_status = mkOption {
      type = attrsOf (attrsOf str);
      default = {};
      description = "Status hilites options set";
      example = literalExpression ''
        {
          hitpoints = {
            "100%" = "grey&normal";
            "<100%" = "green&normal";
            "<66%" = "yellow&normal";
            "<50%" = "orange&normal";
            "<33%" = "red&bold";
          };

          gold.up = "yellow";
          gold.down = "brown";
        }
      '';
    };

    menu_colors = mkOption {
      type = attrsOf str;
      default = {};
      description = "Set of MENUCOLOR= options";
    };

    msg_types = mkOption {
      type = attrsOf (listOf str);
      default = {};
      description = "Set of MSGTYPE= options";
      example = literalExpression ''
        {
          hide = [
            "You swap places with .*"
            "Your tentacles suck the .*"
          ];

          norep = [
            "You see here a.*"
          ];
        }
      '';
    };

    # Choose options {{{
    choose_options = mkOption {
      type = attrsOf (submodule {
        options = {
          nethack_options = mkOption {
            type = attrsOf (oneOf [bool int str]);
            default = {};
            description = "Nethack options";
            example = literalExpression ''
              {
                boulder = "0";
                windowtype = "curses";
                statuslines = 3;
                autopickup = true;
              }
            '';
          };

          hilite_status = mkOption {
            type = attrsOf (attrsOf str);
            default = {};
            description = "Status hilites options set";
            example = literalExpression ''
              {
                hitpoints = {
                  "100%" = "grey&normal";
                  "<100%" = "green&normal";
                  "<66%" = "yellow&normal";
                  "<50%" = "orange&normal";
                  "<33%" = "red&bold";
                };

                gold.up = "yellow";
                gold.down = "brown";
              }
            '';
          };

          menu_colors = mkOption {
            type = attrsOf str;
            default = {};
            description = "Set of MENUCOLOR= options";
          };

          msg_types = mkOption {
            type = attrsOf (listOf str);
            default = {};
            description = "Set of MSGTYPE= options";
            example = literalExpression ''
              {
                hide = [
                  "You swap places with .*"
                  "Your tentacles suck the .*"
                ];

                norep = [
                  "You see here a.*"
                ];
              }
            '';
          };
        };
      });
      default = {};
      description = "Set of CHOOSE= configurations";
      example = literalExpression ''
        {
          elf-wiz = {
            options = {
              race = "elf";
              role = "wizard";
            };
          };

          tourist.options = {
            role = "tourist";
            gender = "male";
          };
        }
      '';
    };
    # }}}
  };
  # }}}

  config = let
    cfg = config.programs.nethack;
  in {
    home = {
      packages = mkIf cfg.enable [
        cfg.package
      ];

      file = {
        ".nethackrc" = {
          inherit (cfg) enable;
          text = generateNethackrc cfg;
        };
      };
    };
  };
}
# vim: et ts=2 sw=2