class PawGen

# File lib/pawgen.rb, line 11
def initialize
  super()
  # The original defaulted the length to 8, but it's a bit too
  # short to be the default length these days -- especially
  # considering that phonemic password construction shrinks
  # the password space.
  @length = 12
  @include_uppercase = true
  @include_digits = true
  @include_symbols = false
  @exclude_ambiguous = false
  @exclude_vowels = false
  @mode = method :anglophonemic
  return
end

# File lib/pawgen.rb, line 135
def self::random_bool probability_of_true
  return SecureRandom.random_number < probability_of_true
end

# File lib/pawgen.rb, line 139
def self::random_item array
  return array[SecureRandom.random_number array.length]
end

# File lib/pawgen.rb, line 223
def anglophonemic
  raise 'unable to generate such a ' +
      'short anglophonemic password' \
      unless length >= 5
  raise 'unable to generate an ' +
      'anglophonemic password with no vowels' \
      if exclude_vowels?

  reqs = 0
  reqs |= REQ_UPPERCASE if include_uppercase?
  reqs |= REQ_DIGITS if include_digits?
  reqs |= REQ_SYMBOLS if include_symbols?
  result, unmet_reqs = [] # declare local variables
  begin
    unmet_reqs = reqs
    first = true
        # also re-set after a digit (but not after a symbol)
    result = ''
    prev_phoneme_flags = 0
    should_be = nil
    while result.length < length do
      should_be ||=
          PawGen.random_item [ANGLOVOWELS, ANGLOCONSONANTS]
      phoneme, phoneme_flags = PawGen.random_item should_be
      next if first and (phoneme_flags & PHF_NOT_FIRST) != 0
      # block a vowel followed by a vowel-dipthong
      next if (prev_phoneme_flags & PHF_VOWEL) != 0 and
          (phoneme_flags & PHF_VOWEL) != 0 and
          (phoneme_flags & PHF_DIPTHONG) != 0
      next if result.length + phoneme.length > length

      if include_uppercase? and
          (first or (phoneme_flags & PHF_CONSONANT) != 0) and
          PawGen.random_bool 0.2 then
        phoneme = phoneme.capitalize
        unmet_reqs &= ~REQ_UPPERCASE
      end

      # Note that the unambiguous lowercase 'o' can become the
      # ambiguous 'O' through capitalisation.  Contrariwise,
      # the ambiguous lowercase 'l' can become the unambiguous
      # uppercase 'L'.
      next if exclude_ambiguous? and
          phoneme.split('').any?{|c| AMBIGUOUS.include? c}

      # All the checks for the phoneme passed.  Let's add it.
      result << phoneme

      break if result.length == length

      # Checking against the [[first]] flag here means
      # requiring at least _two_ phonemes before the digit can
      # appear, because if we just applied the first phoneme,
      # [[first]] is still true.
      if include_digits? and
          !first and
          PawGen.random_bool 0.3 then
        choice = DIGITS.split ''
        choice -= AMBIGUOUS.split '' if exclude_ambiguous?
        result << PawGen.random_item(choice)
        unmet_reqs &= ~REQ_DIGITS
        first = true
        prev_phoneme_flags = 0
        should_be = nil # pick next [[should_be]] at random
        next
      end

      if include_symbols? and
          !first and
          PawGen.random_bool 0.2 then
        choice = SYMBOLS.split ''
        # Our [[AMBIGUOUS]] does not actually contain any
        # symbols in the current version.  This may be a
        # problem, considering [['`]] and [[!/1l|]] and [[&8]]
        # and [[-_]] and [[^~]] and maybe even [[.,]] and
        # [[:;]] and [[()l|]] so we're excluding [[AMBIGUOUS]]
        # anyway in anticipation of a future version
        # mentioning some of those.
        choice -= AMBIGUOUS.split '' if exclude_ambiguous?
        result << PawGen.random_item(choice)
        unmet_reqs &= ~REQ_SYMBOLS
        # not resetting [[first]]; not [[next]]ing
      end

      if should_be.object_id == ANGLOCONSONANTS.object_id then
        should_be = ANGLOVOWELS
      else
        if (prev_phoneme_flags & PHF_VOWEL) != 0 or
            (phoneme_flags & PHF_DIPTHONG) != 0 or
            PawGen.random_bool(0.6) then
          should_be = ANGLOCONSONANTS
        else
          should_be = ANGLOVOWELS
        end
      end
      prev_phoneme_flags = phoneme_flags
      first = false
    end
  end until unmet_reqs.zero?
  return result
end

# File lib/pawgen.rb, line 78
def do_not_exclude_ambiguous!
  @exclude_ambiguous = false
  return self
end

# File lib/pawgen.rb, line 95
def do_not_exclude_vowels!
  @exclude_vowels = false
  return self
end

# File lib/pawgen.rb, line 73
def exclude_ambiguous!
  @exclude_ambiguous = true
  return self
end

# File lib/pawgen.rb, line 69
def exclude_ambiguous?
  return @exclude_ambiguous
end

# File lib/pawgen.rb, line 90
def exclude_vowels!
  @exclude_vowels = true
  return self
end

# File lib/pawgen.rb, line 86
def exclude_vowels?
  return @exclude_vowels
end

# File lib/pawgen.rb, line 131
def generate
  return @mode.call
end

# File lib/pawgen.rb, line 45
def include_digits!
  @include_digits = true
  return self
end

# File lib/pawgen.rb, line 41
def include_digits?
  return @include_digits
end

# File lib/pawgen.rb, line 59
def include_symbols!
  @include_symbols = true
  return self
end

# File lib/pawgen.rb, line 55
def include_symbols?
  return @include_symbols
end

# File lib/pawgen.rb, line 31
def include_uppercase!
  @include_uppercase = true
  return self
end

# File lib/pawgen.rb, line 27
def include_uppercase?
  return @include_uppercase
end

# File lib/pawgen.rb, line 338
def kanaphonemic
  raise 'unable to generate such a ' +
      'short kanaphonemic password' \
      unless length >= 5
  raise 'unable to generate an ' +
      'kanaphonemic password with no vowels' \
      if exclude_vowels?

  reqs = 0
  reqs |= REQ_UPPERCASE if include_uppercase?
  reqs |= REQ_DIGITS if include_digits?
  reqs |= REQ_SYMBOLS if include_symbols?
  result, unmet_reqs = [] # declare local variables
  begin
    unmet_reqs = reqs
    first = true
        # also re-set after a digit (but not after a symbol)
    result = ''
    while result.length < length do
      phoneme = PawGen.random_item KANA_MORAE
      next if result.length + phoneme.length > length

      if include_uppercase? and
          PawGen.random_bool 0.2 then
        phoneme = phoneme.capitalize
        unmet_reqs &= ~REQ_UPPERCASE
      end

      # Note that the unambiguous lowercase 'o' can become the
      # ambiguous 'O' through capitalisation.
      next if exclude_ambiguous? and
          phoneme.split('').any?{|c| AMBIGUOUS.include? c}

      # All the checks for the phoneme passed.  Let's add it.
      result << phoneme

      break if result.length == length

      # Checking against the [[first]] flag here means
      # requiring at least _two_ phonemes before the digit can
      # appear, because if we just applied the first phoneme,
      # [[first]] is still true.
      if include_digits? and
          !first and
          PawGen.random_bool 0.3 then
        choice = DIGITS.split ''
        choice -= AMBIGUOUS.split '' if exclude_ambiguous?
        result << PawGen.random_item(choice)
        unmet_reqs &= ~REQ_DIGITS
        first = true
        next
      end

      if include_symbols? and
          !first and
          PawGen.random_bool 0.2 then
        choice = SYMBOLS
        # Our [[AMBIGUOUS]] does not actually contain any
        # symbols in the current version.  This may be a
        # problem, considering [['`]] and [[!/1l|]] and [[&8]]
        # and [[-_]] and [[^~]] and maybe even [[.,]] and
        # [[:;]] and [[()l|]] so we're excluding [[AMBIGUOUS]]
        # anyway in anticipation of a future version
        # mentioning some of those.
        choice -= AMBIGUOUS.split '' if exclude_ambiguous?
        result << PawGen.random_item(choice)
        unmet_reqs &= ~REQ_SYMBOLS
        # not resetting [[first]]; not [[next]]ing
      end

      first = false
    end
  end until unmet_reqs.zero?
  return result
end

# File lib/pawgen.rb, line 104
def length= new_length
  set_length! new_length
  return new_length
end

# File lib/pawgen.rb, line 50
def no_digits!
  @include_digits = false
  return self
end

# File lib/pawgen.rb, line 64
def no_symbols!
  @include_symbols = false
  return self
end

# File lib/pawgen.rb, line 36
def no_uppercase!
  @include_uppercase = false
  return self
end

# File lib/pawgen.rb, line 109
def set_length! new_length
  raise 'invalid length' \
      unless new_length.is_a? Integer and new_length >= 1
  @length = new_length
  return self
end

# File lib/pawgen.rb, line 143
def structureless
  charset = LOWERCASE
  charset += UPPERCASE if include_uppercase?
  charset += DIGITS if include_digits?
  charset += SYMBOLS if include_symbols?
  charset = charset.split('')
  charset -= AMBIGUOUS.split('') if exclude_ambiguous?
  charset -= VOWELS.split('') if exclude_vowels?
  return (0 ... @length).
      map{PawGen.random_item charset}.
      join ''
end

# File lib/pawgen.rb, line 121
def use_anglophonemic_generator!
  @mode = method :anglophonemic
  return
end

# File lib/pawgen.rb, line 126
def use_kanaphonemic_generator!
  @mode = method :kanaphonemic
  return
end

# File lib/pawgen.rb, line 116
def use_structureless_generator!
  @mode = method :structureless
  return
end