from http import HTTP
import time
import os
import subprocess
import shutil
import re


SIGN = '--'
CRLR = '\r\n'

MAX_CHUNK = 1024 * 512
SEVEN_ZIP_BIN = '/home/tool/bin/7za'

PATH = '/home/tool/config/service/FwPack/'
ZIPPATH = '/tmp/FwPack'

def skipHeader(inp, size):
  while True:
    line = inp.readline()
    size -= len(line)
    if line == CRLR:
      break
  return size


def readFile(inp, out, size, separator):
  datasize = size - len(separator)
  toread = datasize
  while toread > 0:
    time.sleep(0.3)
    if toread >= MAX_CHUNK:
      bytes = inp.read(MAX_CHUNK)
      toread -= MAX_CHUNK
    else:
      bytes = inp.read(toread)
      toread = 0

    out.write(bytes)
  out.flush()
  return len(separator)


def extractFiles(filename):
    
  tmp = re.search('NxFw.+', filename)
  
  # rm possible path (IE) from filename
  if tmp is not None:
    filename = tmp.group()
  else:
    raise HTTP(202, '{"success":false, "msg":"Filename have to start with NxFw"}')

  fullpath = PATH + filename.split('.')[0]  

  if not os.access(fullpath, os.F_OK):
    os.mkdir(fullpath)
  
  p = subprocess.Popen([SEVEN_ZIP_BIN, "x", os.path.join(ZIPPATH,'fw.zip'), "-o{0}".format(fullpath), "-y"],
                preexec_fn=lambda: os.nice(15), close_fds=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

  p.communicate()
  
  if p.returncode != 0:
    raise Exception("Cannot extract formware")

  #if subprocess.call(['unzip', os.path.join(ZIPPATH,'fw.zip'), '-d', fullpath]) != 0:

  os.remove(os.path.join(ZIPPATH,'fw.zip'))


def suckAll(inp):
  try:
    while True:
      inp.read(MAX_CHUNK)
  except:
    pass

def process(request, environ):
  # prepare path
  if not os.access(ZIPPATH, os.F_OK):
    try:
      os.mkdir(ZIPPATH)
    except:
      environ['wsgi.input'].read(int(environ['CONTENT_LENGTH']))
      raise HTTP(202, '{"success":false, "msg":"Firmware update error: error creating path"}')

  #try:
  #  subprocess.call(['mount', '-t', 'tmpfs', '-o', 'size=100M', 'tmpfs', ZIPPATH])
  #except:
  #  environ['wsgi.input'].read(int(environ['CONTENT_LENGTH']))
  #  raise HTTP(202, '{"success":false, "msg":"Firmware update error: error mounting ramdisk"}')
    
  if not os.access(ZIPPATH, os.W_OK):
    suckAll(environ['wsgi.input'])
    raise HTTP(202, '{"success":false, "msg":"Firmware update error: cannot write to target path"}')
 
  try:
    socket = environ['wsgi.input']
    size = int(environ['CONTENT_LENGTH'])
    ct = environ['HTTP_CONTENT_TYPE']
    boundary = ct[ct.index('boundary=') + 9:]
    separator = CRLR + SIGN + boundary + SIGN + CRLR
    
    filename = environ['QUERY_STRING']
    size = skipHeader(socket, size)

    with open(os.path.join(ZIPPATH,'fw.zip'), 'wb') as out:
      size = readFile(socket, out, size, separator)
    socket.read(size)

  except Exception as e:
    suckAll(environ['wsgi.input'])
    errStr = "Firmware update error: %s " % str(e)
    if os.access(ZIPPATH, os.F_OK):
        shutil.rmtree(ZIPPATH)
    raise HTTP(202, '{"success":false, "msg":"%s"}' % errStr)

  try:
    extractFiles(filename)
  except Exception as e:
    errStr = "Firmware update error: %s " % str(e)
    folder = PATH + filename.split('.')[0]
    shutil.rmtree(folder)
    raise HTTP(202, '{"success":false, "msg":"%s"}' % errStr)

  raise HTTP(202, '{"success":true, "msg":"File uploaded"}')