module RbSafe

# File lib/rb_safe/safe.rb, line 5
def self.asdf?(raw)
  # The current implementation treats those passwords that in the same line
  # are "is asdf", e.g. 'qwer' is, 'opas' not.
  keyboard = %w(qwertyuiop, asdfghjkl, zxcvbnm)
  keyboard.any? do |pattern|
    pattern.include?(raw) || pattern.include?(raw.reverse)
  end
end

# File lib/rb_safe/safe.rb, line 14
def self.by_step?(raw)
  delta = raw[1].ord - raw[0].ord
  2.upto(raw.length - 1) do |index|
    return false if raw[index].ord - raw[index - 1].ord != delta
  end
  true
end

# File lib/rb_safe/safe.rb, line 53
def self.check(raw, config = {})
  default_config = { length: 8, freq: 0, min_types: 3, level: STRONG }
  config = default_config.update(config)

  config[:level] = STRONG if config[:level] > STRONG
  raw = raw.to_s
  if raw.length < config[:length]
    return Strength.new(false, 'terrible', 'password is too short')
  elsif asdf?(raw) || by_step?(raw)
    return Strength.new(false, 'simple', 'password has a pattern')
  elsif common_password?(raw, config[:freq])
    return Strength.new(false, 'simple', 'password is too common')
  end
  types = 0
  types += 1 if raw =~ /[a-z]/ # Has lower letter.
  types += 1 if raw =~ /[A-Z]/ # Has upper letter.
  types += 1 if raw =~ /[0-9]/ # Has number.
  types += 1 if raw =~ /[^0-9a-zA-Z]/ # Has mark.
  if types < 2
    return Strength.new(config[:level] <= SIMPLE, 'simple',
                        'password is too simple')
  elsif types < config[:min_types]
    return Strength.new(config[:level] <= MEDIUM, 'medium',
                        'password is good enough, but not strong')
  else
    return Strength.new(true, 'strong', 'password is perfect')
  end
end

# File lib/rb_safe/safe.rb, line 22
def self.common_password?(raw, freq = 0)
  frequent = Words.new.common_passwords.fetch(raw, 0)
  if !freq.zero?
    frequent > freq
  else
    !frequent.zero?
  end
end