import gzip
import select
import socket


def receiveClientLogs(port):
  try:
    # open a server socket which is used to receive logs
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    s.bind(('', port))
    s.listen(1)

    # define a list for client sockets, client ip addresses and client log files
    sockList = []
    addrList = []
    fileList = []

    # keep running this thread
    while 1:
      # accept connections from requesting clients
      readList = []; writeList = []; errorList = []
      readList, writeList, errorList = select.select([s], [], [], 0.001)

      # for each connecting client, add the socket to socket list, add the ip
      # to the address list, and open a logfile which is added to the file list
      for client in readList:
        sock, addr = s.accept()
        sock.setblocking(0)
        sockList.extend([sock])
        addrList.extend([addr])
        fl = open(addr[0] + ".log.gz", 'wb');
        fileList.extend([fl])

      # process all clients that have sent log information
      readList, writeList, errorList = select.select(sockList, [], [], 0.001)
      for client in readList:
        buffer = client.recv(1024)

        # if the buffer is filled with some information, add it to the logfile
        # if the buffer is empty, then the client disconnected, so we clean up
        if buffer:
          fl.write(buffer)
        else:
          index = sockList.index(client)
          fileList[index].close()
          sockList[index].close()
          sockList.remove(sockList[index])
          addrList.remove(addrList[index])
          fileList.remove(fileList[index])
  except AttributeError: # thread shutdown
    return;


def sendLog(logfile, host, port):
  s = None
  for res in socket.getaddrinfo(host, port,socket.AF_UNSPEC,socket.SOCK_STREAM):
    af, socktype, proto, canonname, sa = res
    try:
      s = socket.socket(af, socktype, proto)
    except socket.error, msg:
      s = None
      continue
    try:
      s.connect(sa)
    except socket.error, msg:
      s.close()
      s = None
      continue
    break

  if s is None:
    print 'Failed to send log (could not open socket to server)'
    return

  try:
    gzipFile(logfile)
    fl = open(logfile + ".gz", 'rb')
    buf = fl.read()
    s.send(buf)
    s.close()
  except:
    print "File " + logfile + " does not exist."


# opens the requested file, gzips it and saves it back to disk. The zipped
# file is saved as the original filename plus the '.gz' extension.
# filename -> filename.gz
def gzipFile(filename):
  # read the input file
  fileContent = ""
  fl = open(filename, 'rb')
  fileContent = fl.read()

  # gzip the file
  gzfl = gzip.GzipFile(filename + ".gz", 'wb')
  gzfl.write(fileContent)
  gzfl.close()


# opens the requested file, gunzips it and saves it back to disk. The unzipped
# file is saved as the original filename minus the '.gz' extension.
# filename.gz -> filename
def gunzipFile(filename):
  # decompress the file
  gzfl = gzip.GzipFile(filename, 'rb')
  fileContent = gzfl.read()
  gzfl.close()

  # write to file
  fl = open(filename[:-3], 'w')
  fl.write(fileContent)
  fl.close()