module StringObfuscator

# File lib/string-obfuscator.rb, line 5
def self.obfuscate(value, percent: nil, length: nil, from: :left, max_unobfuscated_length: nil, min_obfuscated_length: nil, obfuscation_character: "*", obfuscation_value: nil)
  raise ArgumentError, "must specify percent or length to obfuscate by" if percent.nil? && length.nil?
  raise ArgumentError, "percent must be between 0 - 100" if !percent.nil? && (percent > 100 || percent < 0)
  raise ArgumentError, "length must be > 0" if !length.nil? && length < 0
  return value unless value.is_a?(String)

  if !percent.nil?
    percent = BigDecimal(percent.to_s)
    obfuscated_length = (value.length * (percent / 100)).ceil
  else
    obfuscated_length = length
  end
  obfuscated_length = [obfuscated_length, min_obfuscated_length].max if min_obfuscated_length
  obfuscated_length = [obfuscated_length, value.length].min
  visible_length = value.length - obfuscated_length

  # If `max_unobfuscated_length` is set, ensure that we don't show more than that.
  if !max_unobfuscated_length.nil? && visible_length > max_unobfuscated_length
    visible_length = max_unobfuscated_length
    obfuscated_length = value.length - visible_length
  end

  obfuscation_value ||= obfuscation_character * obfuscated_length
  if visible_length == 0
    obfuscation_value
  elsif from.to_sym == :left
    obfuscation_value + value[-visible_length..-1]
  else
    value[0..(visible_length - 1)] + obfuscation_value
  end
end