# 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 ValueAppendPlugin do
  use Plugin
  require Logger

  @spec transform(map, map) :: [map]
  def transform(dict, options) do
    new_dict = if not MapUtils.all_required_keys?(options, ["key", "value"]) do
      dict
    else
      key = options["key"]
      value = options["value"]

      old_value = Map.get(dict, key, [])
      old_value_list = cond do
	is_list(old_value) -> old_value
	true -> [old_value]
      end

      new_value = [value|old_value_list]
      Map.put(dict, key, new_value)
    end
    [new_dict]
  end
end