{ lib, ... }:
with lib;
rec {
  # vim dictionaries are, in theory, compatible with JSON
  toVimDict = args: toJSON
    (lib.filterAttrs (n: v: !isNull v) args);

  # Black functional magic that converts a bunch of different Nix types to their
  # lua equivalents!
  toLuaObject = args:
    if builtins.isAttrs args then
      if hasAttr "__raw" args then
        args.__raw
      else
        "{" + (concatStringsSep ","
          (mapAttrsToList
            (n: v:
              if head (stringToCharacters n) == "@" then
                toLuaObject v
              else "[${toLuaObject n}] = " + (toLuaObject v))
            (filterAttrs (n: v: !isNull v && toLuaObject v != "{}") args))) + "}"
    else if builtins.isList args then
      "{" + concatMapStringsSep "," toLuaObject args + "}"
    else if builtins.isString args then
    # This should be enough!
      builtins.toJSON args
    else if builtins.isPath args then
      builtins.toJSON (toString args)
    else if builtins.isBool args then
      "${ boolToString args }"
    else if builtins.isFloat args then
      "${ toString args }"
    else if builtins.isInt args then
      "${ toString args }"
    else if isNull args then
      "nil"
    else "";

  # Generates maps for a lua config
  genMaps = mode: maps:
    let
      normalized = builtins.mapAttrs
        (key: action:
          if builtins.isString action then
            {
              silent = false;
              expr = false;
              unique = false;
              noremap = true;
              script = false;
              nowait = false;
              action = action;
            }
          else action)
        maps;
    in
    builtins.attrValues (builtins.mapAttrs
      (key: action:
        {
          action = action.action;
          config = lib.filterAttrs (_: v: v) {
            inherit (action) silent expr unique noremap script nowait;
          };
          key = key;
          mode = mode;
        })
      normalized);

  # Creates an option with a nullable type that defaults to null.
  mkNullOrOption = type: desc: lib.mkOption {
    type = lib.types.nullOr type;
    default = null;
    description = desc;
  };

  defaultNullOpts = rec {
    mkNullable = type: default: desc: mkNullOrOption type (
      let
        defaultDesc = "default: `${default}`";
      in
      if desc == "" then defaultDesc else ''
        ${desc}

        ${defaultDesc}
      ''
    );

    mkInt = default: mkNullable lib.types.int (toString default);
    mkBool = default: mkNullable lib.types.bool (if default then "true" else "false");
    mkStr = default: mkNullable lib.types.str ''"${default}"'';
    mkEnum = enum: default: mkNullable (lib.types.enum enum) ''"${default}"'';
    mkEnumFirstDefault = enum: mkEnum enum (head enum);
  };

  mkPlugin = { config, lib, ... }: { name
                                   , description
                                   , package ? null
                                   , extraPlugins ? [ ]
                                   , extraPackages ? [ ]
                                   , options ? { }
                                   , ...
                                   }:
    let
      cfg = config.plugins.${name};
      # TODO support nested options!
      pluginOptions = mapAttrs (k: v: v.option) options;
      globals = mapAttrs'
        (name: opt: {
          name = opt.global;
          value = if cfg.${name} != null then opt.value cfg.${name} else null;
        })
        options;
      # does this evaluate package?
      packageOption = if package == null then { } else {
        package = mkOption {
          type = types.package;
          default = package;
          description = "Plugin to use for ${name}";
        };
      };
    in
    {
      options.plugins.${name} = {
        enable = mkEnableOption description;
      } // packageOption // pluginOptions;

      config = mkIf cfg.enable {
        inherit extraPackages globals;
        # does this evaluate package? it would not be desired to evaluate pacakge if we use another package.
        extraPlugins = extraPlugins ++ optional (package != null) cfg.package;
      };
    };

  globalVal = val:
    if builtins.isBool val then
      (if val == false then 0 else 1)
    else val;

  mkDefaultOpt = { type, global, description ? null, example ? null, default ? null, value ? v: (globalVal v), ... }: {
    option = mkOption {
      type = types.nullOr type;
      default = default;
      description = description;
      example = example;
    };

    inherit value global;
  };

  extraOptionsOptions = {
    extraOptions = mkOption {
      default = { };
      type = types.attrs;
      description = ''
        These attributes will be added to the table parameter for the setup function.
        (Can override other attributes set by nixvim)
      '';
    };
  };

  mkRaw = r: { __raw = r; };

  wrapDo = string: ''
    do
      ${string}
    end
  '';

  rawType = types.submodule {
    options = {
      __raw = mkOption {
        type = types.str;
        description = "raw lua code";
        default = "";
      };
    };
  };

  isRawType = v: lib.isAttrs v && lib.hasAttr "__raw" v && lib.isString v.__raw;
}