# Statement Devise a function that gets one parameter 'w' and returns all the
# anagrams for 'w' from the file wl.txt. The file wl.txt contains a huge list of
# valid words and the idea is to find the anagrams of ‘w’ included in such a
# list.
#
#   "Anagram": An anagram is a type of word play, the result of rearranging the
# letters of a word or phrase to produce a new word or phrase, using all the
# original letters exactly once; for example orchestra can be rearranged into
# carthorse.
#
#   anagrams("horse") should return: ['heros', 'horse', 'shore']
#
# You can assume the absolute/relative path to wl.txt to be fixed and, therefore
# hardcore in the code, or you can also change the firm of the method to for
# example anagrams("horse", ./wl.txt).
#
class AnagramCalculator
  attr_reader :database_file

  def initialize(database_file:)
    @database_file = database_file
  end

  def call(input)
    database
      .select { |w| w.length == input.length }
      .select { |w| anagram?(input, w) }
  end

  private

  def database
    @database ||= File.read(database_file).split("\n")
  end

  def anagram?(word1, word2)
    word2_bytes = word2.bytes

    word1.bytes.select do |b|
      word2_bytes.delete(b).nil?
    end.empty?
  end
end

database_file = '/Users/dpereira/Downloads/wl.txt'
puts AnagramCalculator
  .new(database_file: database_file)
  .call('esroh')