# Reads and writes to MontyLingua.
# (Put this file and subbot.org/montylingua/MontyLingua2.py 
#  in the MontyLingua directory.)

class MontyLingua

  def initialize
    @monty = IO.popen("python MontyLingua2.py", "r+")
    16.times { |i|  # Read the lines preceding the first prompt
      line = @monty.gets
      puts line
    }
  end

  def putstr(s = '')
    s.strip!
    @monty.puts s
    getstr
  end

  def getResponse(s = '')
    return putstr(s)
  end

  def getstr
    full_response = ""
    @monty.gets  # skip over two blank lines
    @monty.gets
    while (line = @monty.gets) =~ /^.*/
      full_response << line << " "
      c = @monty.getc # Check the first character of the next line
      if c == nil then break end
      if c.chr == ">" then break end # If it's the first chr of a prompt, break
      @monty.ungetc(c) #If it's not a prompt, push the chr back on the stream.
    end
    return full_response
  end

  # Try to find the subject.
  def getSubject(input = '')
    if input =~ /^In (?:.*?), (.*)/i
      #puts $1
      return getSubject($1)
    end
    parse = getResponse(input)
    arr = parse.split("\n")
    constituents = arr[0]
    if constituents =~ /\(NX (.*?) NX\)/
      subject = postprocess $1.to_s
      return "#{subject}"
    end 
    return "I don't know what the subject in #{input} is."
  end

  # Try to get the main verb.
  def getVerb(input = '')
    parse = getResponse(input)
    constituents = parse.split("\n")[0]
    if constituents =~ /\(VX (.*?) VX\)/
      verb = postprocess $1.to_s
      return verb
    end
    return "I don't know what the verb in #{input} is."
  end

  # Try to get the object.
  def getObject(input = '')
    parse = getResponse(input)
    constituents = parse.split("\n")[0]
    if constituents =~ /VX\) .*?\(NX (.*?) NX\)/
      object = postprocess $1.to_s
      return object
    end
    return "I don't know what the object in #{input} is."
  end

  # Return the constituent tree.
  def getConstituents(input = '')
    parse = getResponse(input)
    return parse.split("\n")[0]
  end

  # Strip tags from MontyLingua's output.
  def postprocess(phrase = '')
    if phrase == '' then return '' end
    phrase.gsub!(/\/[A-Z]*/, '')
    return phrase 
  end

end

if $0 == __FILE__
  monty = MontyLingua.new
  print "\n> "; $stdout.flush
  quitwords = [":q", "quit", "bye", "exit"]
  while (line = gets) !~ /^(#{quitwords.join('|')})+/ and line !~ /^$/
    line.chomp!
    puts
    puts monty.getSubject(line)
    puts monty.getVerb(line)
    puts monty.getObject(line)
    #puts monty.getConstituents(line)
    print "\n> "; $stdout.flush
  end
  print "Bye!"
end