# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

defmodule ValuesCasePlugin do
  use Plugin
  require Logger
  def transform(dict, options) do
    if  not MapUtils.all_required_keys?(options, ["keys", "case"]) do
      dict
    else
      keys_dict = Map.keys(dict)
      keys_to_change = options["keys"]
      keys = ListUtils.intersection(keys_dict, keys_to_change)
      List.foldl(keys, dict,
        fn k, acc ->
          old_value = acc[k]
          new_value = if not is_binary(old_value), do: old_value, else: if options["case"] == "lower", do: String.downcase(old_value), else: String.upcase(old_value)
          if old_value != new_value do
            Logger.warn("updating key '" <> k <> "' from value '" <> old_value <> "' to value '" <> new_value <> "'")
            Map.replace!(acc, k, new_value)
          else
            acc
          end
        end)
    end
  end

end