require File.dirname(__FILE__) + '/../config/environment.rb'
require 'socket'
require 'thread'
require 'nntp'
require 'log4r'

#include Log4r

PORT = 9999
MAX_CONNS_PER_IP = 3
MAX_CONNS = 30

logger = Log4r::Logger.new "nntpd"
logger.outputters = Log4r::Outputter.stdout

Thread.abort_on_exception = true
server = TCPserver.open(PORT)
logger.info "Listening on #{PORT}"

conns_counter_mutex = Mutex.new
conns = 0
conns_per_ip = Hash.new

loop do
  socket = server.accept
  ip = socket.peeraddr[3]
  logger.info "connection from #{ip}"

  if conns >= MAX_CONNS
    logger.info "too many connections"
    socket.warn "502 Too many connections\r\n"
    socket.shutdown
    next
  end
  if conns_per_ip[ip].to_i >= MAX_CONNS_PER_IP
    logger.warn "too many connections from #{ip}"
    socket.write "502 Too many connections from #{ip}\r\n"
    socket.shutdown
    next
  end

  conns_counter_mutex.synchronize do
    conns += 1
    if conns_per_ip[ip] == nil
      conns_per_ip[ip] = 1
    else
      conns_per_ip[ip] += 1
    end
  end

  Thread.start(socket, ip, logger) do |socket, ip, logger|
    begin
      NNTPSession.new(socket, logger).serve
    rescue => err
      logger.error err
    ensure
      socket.shutdown rescue nil
      GC.start
      conns_counter_mutex.synchronize do
        conns -= 1
        conns_per_ip[ip] -= 1
      end
      logger.info "connection to #{ip} lost"
    end
  end

end