#!/usr/local/bin/ruby
require 'net/http'

class JTwixtFormatter
  def formatInt4Pair(key, value)
    return formatKey(key) +
           format4byteInt(4) +
           format4byteInt(value)
  end

  def formatInt1Pair(key, value)
    return formatKey(key) +
           format4byteInt(1) +
           format1byteInt(value)
  end

  def formatStringPair(key, value)
    return formatKey(key) +
           format4byteInt(value.length) +
           value
  end

  def formatKey(key)
    return format1byteInt(key.length) +
           key
  end

  def format4byteInt(value)
    return format2byteInt(value / (2**16)) +
           format2byteInt(value)
  end

  def format2byteInt(value)
    return format1byteInt(value / (2**8)) +
           format1byteInt(value)
  end

  def format1byteInt(value)
    return format("%c", value)  # just the lowest 8 bits
  end

  def formatStandardTwixtHeader(player1, player2)
    header = formatInt4Pair("gtv", 2);

    if player1 != nil
      header += formatStringPair("player1", player1)
    end

    if player2 != nil
      header += formatStringPair("player2", player2)
    end

    header += formatInt1Pair("pov", 0) +      # point of view (0 = alternate)
              formatStringPair("type", "twixt1") +
              formatInt4Pair("bdsize", 24) +  # board size
              formatInt4Pair("tgtv", 1) +     # twixt game tree version
              format2byteInt(0)

    return header
  end

  def formatMove(move)
    return format2byteInt(1) +   # one node (no tree)
           formatKey("m") +      # m for "move"
           format2byteInt(move.length) +
           move +
           format1byteInt(0)
  end

  def formatCoordinates(x, y)
    return format1byteInt(x - 1) +
           format1byteInt(y - 1)
  end

  def formatSimpleMove(x, y, player)
    return formatCoordinates(x, y) +
           format1byteInt(player)
  end

  def formatShortMove(x, y, player)
    return formatMove(formatSimpleMove(x, y, player))
  end
end

class LittleGolemParser
  def initialize(game)
    @game = game
  end

  def getPlayer1
    p = @game.scan(/PB\[[^\]]*\]/)[0]
    return p[3..(p.length - 2)]
  end

  def getPlayer2
    p = @game.scan(/PW\[[^\]]*\]/)[0]
    return p[3..(p.length - 2)]
  end

  def getMoves
    moves = @game.scan(/[br]\[[^\]]*\]/)
  end

  def getWinner
    p = @game.scan(/[br]\[resign\]/)[0]
    if p == nil
      return nil
    else
      return " rb".index(p[0])
    end
  end

  def forEachMove
    letters=" abcdefghijklmnopqrstuvwx"
    moves = getMoves

    # swap rule
    if moves.length > 1 and moves[1] == "r[swap]"
      move = moves[0]
      x = letters.index(move[3])
      y = letters.index(move[2])
      yield x, y, 1       # place red peg first so Jtwixt doesn't get confused
      yield x, y, 2       # then put black peg right on top of it.
      moves.delete_at(1)  # remove the swap move
      moves.delete_at(0)  # remove the first move
    end

    # the rest of the moves
    for move in moves
      if move.length > 4 and (move[4..4] == "]" or move[4..4] == "|") 
        player = " br".index(move[0])
        x = letters.index(move[2])
        y = letters.index(move[3])
        yield x, y, player
      end
    end
  end
end

def getJtwixtFileData(lgolem)
    jtwixt = JTwixtFormatter.new

    jtwixtFileData = jtwixt.formatStandardTwixtHeader(lgolem.getPlayer1, 
                                                      lgolem.getPlayer2)
    lgolem.forEachMove { |x, y, player|
      
      jtwixtFileData += jtwixt.formatShortMove(x, y, player)
    }

    return jtwixtFileData + jtwixt.format2byteInt(0)
end

def getGame(httpConnection, gameId)
  directory = "/jsp/game/png.jsp?gid="
  lgResponse, lgData = httpConnection.get(directory + gameId)

  if lgResponse.code == "500"
    print "No such game: ", gameId, "\n"
  elsif lgResponse.code != "200"
    print "HTTP error ", lgResponse.code, " for game: ", gameId, "\n"
  else
    lgolem = LittleGolemParser.new(lgData)

    jtwixtFileData = getJtwixtFileData(lgolem)
    jtwixtFileName = "game" + gameId + ".tgt"
    File.new(jtwixtFileName, "wb").write(jtwixtFileData)

    print jtwixtFileName, ": ",
          (lgolem.getWinner == 1)? "*":"",
          lgolem.getPlayer1, " vs. ",
          (lgolem.getWinner == 2)? "*":"",
          lgolem.getPlayer2, "\n"
  end
end

httpConnection = Net::HTTP::new("www.littlegolem.net")

for gameId in ARGV
  getGame(httpConnection, gameId)
end