class Mkpasswd

# File lib/mkpasswd.rb, line 21
def initialize(args)
  self.options = OpenStruct.new
  options.hashmethod = 'sha-512'
  options.hasher     = HASHERS[options.hashmethod]

  OptionParser.new do |opts|
    opts.banner = "Usage: #{File.basename $0} [options] [PASSWORD [SALT]]"
    opts.separator 'Encrypts password using the unix-crypt gem with CLI compatible with mkpasswd utility from whois package.'
    opts.separator ''
    opts.separator 'Options:'

    opts.on('-m', '--method=METHOD', String, 'Set hash algorithm [sha-512 (default), sha-256, md5, des]') do |hasher|
      if hasher.to_s == 'help'
        puts 'Available methods:'
        puts HASHERS.keys
        exit
      end
      options.hashmethod = hasher.to_s.downcase
      options.hasher     = HASHERS[options.hashmethod]
      raise 'Invalid hash algorithm for -m/--method' if options.hasher.nil?
    end

    opts.on('-S', '--salt [SALT]', String, 'Provide hash salt') do |salt|
      raise 'Invalid salt for -S/--salt' if salt.nil?
      options.salt = salt
    end

    opts.on('-s', 'Read input from stdin') do
      options.read_from_stdin = true
    end

    opts.on('-R', '--rounds [ROUNDS]', Integer, 'Set number of hashing rounds (SHA256/SHA512 only)') do |rounds|
      raise 'Invalid hashing rounds for -R/--rounds' if rounds.nil? || rounds.to_i <= 0
      options.rounds = rounds
    end

    opts.on_tail('-h', '--help', 'Show this message') do
      puts opts
      exit
    end

    opts.on_tail('-V', '--version', 'Show version') do
      puts Mkpasswd::VERSION
      exit
    end
  end.parse!(ARGV)

  options.password = ARGV.shift
  if options.password
    $0 = $0 # this invocation will get rid of the command line arguments from the process list
  elsif options.read_from_stdin
    options.password = $stdin.read.chomp
  else
    options.password = ask_password
  end
  options.salt = ARGV.shift  unless options.salt

  saltsize = options.salt.to_s.bytesize
  if saltsize > 0 && ( saltsize < 8 || saltsize > 16 )
    raise "Wrong salt length: #{saltsize} bytes when 8 <= n <= 16 expected."
  end
end

# File lib/mkpasswd.rb, line 88
def ask_noecho(message)
  $stderr.print message
  if $no_io_console
    begin
      `stty -echo`
      result = gets
    ensure
      `stty echo`
    end
  else
    result = $stdin.noecho(&:gets)
  end
  $stderr.puts
  result
end

# File lib/mkpasswd.rb, line 104
def ask_password
  password = ask_noecho("Enter password: ")
  twice    = ask_noecho("Verify password: ")
  raise "Passwords don't match" if password != twice
  password.chomp!
end

# File lib/mkpasswd.rb, line 84
def execute!
  puts options.hasher.build(options.password, options.salt, options.rounds)
end