defmodule Medicode.Utilities do
  @moduledoc """
  Contains general utility functions that are not specific to a domain or context in the system.
  """

  @doc "Takes an enumerable of atoms and tallies a count for how often each appears."
  def tally(enumerable) do
    Enum.reduce(enumerable, %{}, fn item, acc ->
      if Map.has_key?(acc, item) do
        Map.put(acc, item, acc[item] + 1)
      else
        Map.put(acc, item, 1)
      end
    end)
  end

  @doc "Takes the output of `tally/1` and returns a string representation."
  def tally_to_string(tallied_enumerable) do
    tallied_enumerable
    |> Enum.map_join(", ", fn {key, value} -> "#{key} (#{value})" end)
  end

  def map_set_toggle(map_set, item) do
    if Enum.any?(map_set, &(&1 == item)) do
      Enum.reject(map_set, &(&1 == item))
    else
      map_set ++ [item]
    end
  end
end