# Proxy of ruby-debug-ide for remote debugging
# Version::   0.1
# Author::    Rikiya Ayukawa  (mailto:dbc.ginriki@gmail.com)
# Copyright:: Copyright (c) 2010
# License::   Distributes under the MIT License: http://mbed.org/license/mit

require 'logger'
require 'socket'
require 'rexml/document'
require 'optparse'

include REXML

$logger = Logger.new(STDOUT)

RDB_PORT = 1234
PORT = 7000

def replace(path)
  return path.gsub(Regexp.new("^#{$config['rdbprefix']}"), $config["ideprefix"])
end

def replace_cmdpath(cmdpath, cmd = "b")
  case cmd
  when "b"
    tmp = cmdpath.gsub("b #{$config['ideprefix']}", "b #{$config['rdbprefix']}")
    tmp.gsub!("\\", File::SEPARATOR)
    return tmp
  end
end

def xml_filter(xml)
  doc = Document.new(xml)
  root = doc.root
  XPath.each(doc, "//suspended|//breakpoint|//frames/frame") do |elem|
    if elem.attributes["file"]
      file = elem.attributes["file"]
      elem.attributes["file"] = 
        file.gsub($config["rdbprefix"], $config["ideprefix"])
    end
  end

  XPath.each(doc, "//breakpointAdded") do |elem|
    if elem.attributes["location"]
      file = elem.attributes["location"]
      elem.attributes["location"] = 
        file.gsub($config["rdbprefix"], $config["ideprefix"])
    end
  end
  return doc.to_s
end

def read_xmlend(io)
  recv_xml = ""
  loop do
    # FIXME: I expect IO.select return array which include [io]
    #        in case that io buffer remains,
    #        but that of JRuby causes timeout and returns nil.
    # rl = IO.select([io], nil, nil, 3)
    # raise "Timeout: incomplete xml= #{recv_xml}" unless rl
    
    s = io.gets(">")
    raise "EOF: incomplete xml= #{recv_xml}" unless s
    
    recv_xml += s
    begin
      Document.new(recv_xml)
      return recv_xml
    rescue ParseException
    end
  end
end

def get_config
  config = {}
  config["rdb_port"] = RDB_PORT
  config["port"] = PORT
  config["rdbprefix"] = "/"
  config["ideprefix"] = "C:/"

  opts = OptionParser.new
  opts.on("-t <rdb_host>"){|v|
    args = v.split(":")
    config["rdb_host"] = args[0]
    config["rdb_port"] = args[1].to_i if args[1]
  }
  opts.on("-p <listen_port>"){|v|
    config["port"] = v.to_i
  }
  opts.on("--rdbprefix <prefix>"){|v|
    config["rdbprefix"] = v
  }
  opts.on("--ideprefix <prefix>"){|v|
    config["ideprefix"] = v
  }
  opts.on("-d"){|v|
    config["debug"] = true
  }
  opts.parse(ARGV)
  raise "rdb_host must be specified." unless config["rdb_host"]
  return config
end

def usage
  $stderr.puts("Usage: #{$0} -t <rdb_host> [-p listen_port] [--rdbprefix prefix] [--ideprefix prefix] [-d]")
  $stderr.puts("")
  $stderr.puts("Example: #{$0} -t localhost --rdbprefix \"/home/user/script\" --ideprefix \"C:\\\\win_script\" -d")
  $stderr.puts("")
end

def main
  begin
    $config = get_config
  rescue => ex
    usage
    raise ex
  end
  if $config["debug"]
    $logger.level = Logger::DEBUG
  else
    $logger.level = Logger::INFO
  end
  $logger.info("proxy will replace #{$config['rdbprefix']} with #{$config['ideprefix']}")
  $logger.info("proxy listens on 0.0.0.0:#{$config['port']}")
  ide_proxy = TCPServer.open($config["port"])
  ide = ide_proxy.accept
  $logger.info("proxy connects to #{$config['rdb_host']}:#{$config['rdb_port']}")
  rdb = TCPSocket.open($config["rdb_host"], $config["rdb_port"])
  $logger.info("debug start")

  eof_flag = false
  until eof_flag
    rl = IO.select([ide, rdb], nil, nil, 3)
    next unless rl
    rl.first.each do |io|
      if io == ide
        if io.eof?
          eof_flag = true
        else
          cmd = io.gets
          $logger.debug("(ide -> proxy) #{cmd}")
          cmd = replace_cmdpath(cmd)
          $logger.debug("(proxy -> rdb) #{cmd}")
          rdb.write(cmd)
        end
      elsif io == rdb
        if io.eof?
          eof_flag = true
        else
          recv_xml = read_xmlend(rdb)
          $logger.debug("(rdb -> proxy) #{recv_xml}")
          send_xml = xml_filter(recv_xml)
          $logger.debug("(proxy -> ide) #{send_xml}")
          ide.write(send_xml)
        end
      end
    end
  end

  rdb.close
  ide.close
  ide_proxy.close
  
end

main