module CodeKindly
  module Utils
    class Boolean
      # modified from ActiveRecord::ConnectionAdapters::Column (4.2.9)
      TRUE_VALUES  = [true, 1, '1', 't', 'T', 'true', 'TRUE', 'on', 'ON', 'y', 'yes']
      FALSE_VALUES = [false, 0, '0', 'f', 'F', 'false', 'FALSE', 'off', 'OFF', 'n', 'no']

      class << self
        def from (value)
          return true  if is_true?(value)
          return false if is_false?(value)
          nil
        end

        def is_false? (value)
          return true if FALSE_VALUES.include?(value)
          if value.respond_to?(:downcase)
            return true if FALSE_VALUES.include?(value.downcase)
          end
          false
        end

        def is_true? (value)
          return true if TRUE_VALUES.include?(value)
          if value.respond_to?(:downcase)
            return true if TRUE_VALUES.include?(value.downcase)
          end
          false
        end
      end
    end
  end
end