#!/usr/local/bin/ruby

require 'socket'
require 'net/http'
require 'cgi'
require 'kconv'
require 'timeout'

# 定数
TIME_LIMIT = 30
EXPIRE_TIME = 60 * 60 *24 * 30
SAKURA_PORT = 9801
HTTP_PORT = 80
MAX_DATA_SIZE = 2014

# クッキー取得
cgi = CGI::new
cookies = cgi.cookies

begin
  # 適当にタイムアウト
  timeout(TIME_LIMIT) do

    # さくらとも呼ばれるひとかチェック
#    addr = ENV['HTTP_X_FORWARDED_FOR'] || ENV['REMOTE_ADDR']
    addr = ENV['REMOTE_ADDR']
    TCPSocket.open(addr, SAKURA_PORT).close
    
    # 更新情報を取得
    url = ENV['QUERY_STRING']
    raise unless %r|http://(.+?)(/.+)| =~ url
    host, port, path = $1, HTTP_PORT, $2
    host, port = $1, $2 if host =~ /(.+):(.+)/
    response, body = Net::HTTP.new(host, port).get(path) 

    # 取得した更新情報を解析
    kcode = Kconv::guess(body)
    if kcode != Kconv::SJIS
      body = Kconv::kconv body, Kconv::SJIS, kcode
    end
    update = body.split(/[\r\n]+/)
    author = update.shift
    first = update.shift
    second = update.shift
    update.map!{|line|
      next unless line =~ %r|(\d+)/(\d+)/(\d+)\s+(\d+):(\d+)\s+(.+)|
      [ Time::local($1, $2, $3, $4, $5), $6 ]
    }
    update.compact!
    
    # 現在時間とクッキーのexpire時間
    now = Time::now
    expires = now + EXPIRE_TIME
    
    # スクリプト作成
    unless cookies.include? url
      script = first
    else
      cookies[url].expires = expires
      update.reject!{|u| u[0] < now}
      raise if update.empty?
      update.collect!{|u| u[1]}
      script = second + '\n' + update.join('\n')
    end
    
    # 送信データ作成
    data = <<-"END"
SEND SSTP/1.0\r
Sender: #{author}\r
Script: #{script}\\e\r
\r
    END

    # データサイズが2KB以内になるように丸め込む
    while data.size > MAX_DATA_SIZE
      raise unless data.sub!(/(^Script: .*?\\n).*?\\n/, '\1')
    end

    # データ送信
    sock = TCPSocket.open(addr, SAKURA_PORT)
    sock.write data

    # 終了ステータスをチェック
    raise unless %r|SSTP/\d.\d 200 OK| =~ sock.read

    # クッキー更新
    unless cookies.include? url
      cookies[url] = CGI::Cookie::new ('name' => url,
				       'value' => [ now.to_i.to_s ],
				       'expires' => expires)
    else
      cookies[url].value = [ now.to_i.to_s ]
    end
  end

rescue
end

# ダミーGIF送信
cgi.out ('cookie' => cookies,
	 'type' => 'image/gif') {
  "GIF89a\001\000\001\000\200" +
  "\000\000\377\377\377\000\000\000!\371" + 
  "\004\001\000\000\000\000,\000\000\000" +
  "\000\001\000\001\000\000\002\002D\001" +
  "\000;"
}