class Rexical::Cmd

def initialize
  @status  =  2
  @cmd  =  File.basename($0, ".rb")
  tmp  =  OPTIONS.lines.collect do |line|
      next if /\A\s*\z/ === line
      # disp, sopt, lopt, takearg, doc
      _, sopt, lopt, takearg, _  =  line.strip.split(/\s+/, 5)
      a  =  []
      a.push lopt    unless lopt == '-'
      a.push sopt    unless sopt == '-'
      a.push takearg == '-' ?
             GetoptLong::NO_ARGUMENT : GetoptLong::REQUIRED_ARGUMENT
      a
  end
  getopt  =  GetoptLong.new(*tmp.compact)
  getopt.quiet  =  true
  @opt  =  {}
  begin
    getopt.each do |name, arg|
      raise GetoptLong::InvalidOption,
          "#{@cmd}: #{name} given twice" if @opt.key? name
      @opt[name]  =  arg.empty? ? true : arg
    end
  rescue GetoptLong::AmbiguousOption, GetoptLong::InvalidOption,
         GetoptLong::MissingArgument, GetoptLong::NeedlessArgument
    usage $!.message
  end
  usage    if @opt['--help']
  if @opt['--version']
    puts "#{@cmd} version #{Rexical::VERSION}"
    exit 0
  end
  if @opt['--copyright']
    puts "#{@cmd} version #{Rexical::VERSION}"
    puts "#{Rexical::Copyright} <#{Rexical::Mailto}>"
    exit 0
  end
end

def run
  @status  =  1
  usage 'no grammar file given'    if ARGV.empty?
  usage 'too many grammar files given'    if ARGV.size > 1
  filename  =  ARGV[0]
  rex  =  Rexical::Generator.new(@opt)
  begin
    rex.grammar_file  =  filename
    rex.read_grammar
    rex.parse
    if @opt['--check-only']
      $stderr.puts "syntax ok"
      return  0
    end
    rex.write_scanner
    @status  =  0
  rescue Rexical::ParseError, Errno::ENOENT
    msg  =  $!.to_s
    unless /\A\d/ === msg
      msg[0,0]  =  ' '
    end
    $stderr.puts "#{@cmd}:#{rex.grammar_file}:#{rex.lineno}:#{msg}"
  ensure
    exit @status
  end
end

def usage( msg=nil )
  f  =  $stderr
  f.puts "#{@cmd}: #{msg}"  if msg
  f.print <<-EOT
age: #{@cmd} [options] <grammar file>
tions:
  EOT
  OPTIONS.each_line do |line|
    next if line.strip.empty?
    if /\A\s*\z/ === line
      f.puts
      next
    end
    disp, sopt, lopt, takearg, doc  =  line.strip.split(/\s+/, 5)
    if disp == 'o'
      sopt  =  nil if sopt == '-'
      lopt  =  nil if lopt == '-'
      opt  =  [sopt, lopt].compact.join(',')
      takearg  =  nil if takearg == '-'
      opt  =  [opt, takearg].compact.join(' ')
      f.printf "%-27s %s\n", opt, doc
    end
  end
  exit @status
end