#!/usr/bin/ruby

require "socket"

$KCODE='u'

COMMAND_CODE_ZIP_TO_ADDR = 0x01
COMMAND_CODE_ZIP_TO_ADDR_RESPONSE = 0x02

COMMAND_CODE_ADDR_TO_ZIP = 0x11
COMMAND_CODE_ADDR_TO_ZIP_RESPONSE = 0x12


def resp(code, ver, converted, zip, addr, udp_sock, peer)
  addr = (addr ? addr.tr("\0", "") : "")
  #p peer
  len = 1 + 7 + addr.size + 1
  len_h = len / 256
  len_l = len % 256
  msg = " " * len 

  msg[0] = code
  msg[1] = ver
  msg[2] = len_h
  msg[3] = len_l
  msg[4] = converted
  msg[5..11] = zip ? zip : "0000000"
  msg[12..-1] = addr + "\0"

  udp_sock.send(msg, 0, peer[3], peer[1])
end


def zip_to_addr_ver1(zip, udp_sock, peer)
  zip_to_addr_map = {
    "1000004" => "東京都千代田区大手町",
  }

  addr = zip_to_addr_map[zip]
  #puts "#{zip} => #{addr}"

  resp COMMAND_CODE_ZIP_TO_ADDR_RESPONSE, 1, addr ? 1 : 0, zip, addr, udp_sock, peer
end


def addr_to_zip_ver1(addr, udp_sock, peer)
  addr_to_zip_map = {
    "東京都千代田区大手町" => "1000004",
  }
  
  zip = addr_to_zip_map[addr.tr("\0", "")]
  #puts "#{addr} => #{zip}"

  resp COMMAND_CODE_ADDR_TO_ZIP_RESPONSE, 1, zip ? 1 : 0, zip, addr, udp_sock, peer
end


fntbl = {
  [ COMMAND_CODE_ZIP_TO_ADDR, 1 ] => method(:zip_to_addr_ver1),
  [ COMMAND_CODE_ADDR_TO_ZIP, 1 ] => method(:addr_to_zip_ver1),
}


begin
  udp_sock = UDPSocket.open()
  udp_sock.bind("0.0.0.0", 10000)

  loop do
    Thread.start(udp_sock.recvfrom(65535)) do |r|
      msg = r[0]
      peer = r[1]

      code = msg[0]
      ver = msg[1]
      len_h = msg[2]
      len_l = msg[3]
      len = (len_h << 8) + len_l

      fntbl[[code, ver]].call(msg[4, len], udp_sock, peer)
    end
  end

rescue

ensure
  udp_sock.close if udp_sock != nil
end