#!/usr/bin/env python
#
# Copyright 2013 Jeff Rebeiro (jeff@rebeiro.net) All rights reserved
# Simple UPNP MediaServer implementation for PC Autobackup

__author__ = 'jeff@rebeiro.net (Jeff Rebeiro)'

import HTMLParser
import logging
import os
import random
import re
import string
import xml.dom.minidom

from twisted.internet import reactor
from twisted.web.error import NoResource
from twisted.web.resource import Resource
from twisted.web.server import Site

import common

CREATE_OBJ = '"urn:schemas-upnp-org:service:ContentDirectory:1#CreateObject"'
CREATE_OBJ_DIDL = re.compile(r'<Elements>(?P<didl>.*)</Elements>')
CREATE_OBJ_RESPONSE = '''<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
  <s:Body>
    <u:CreateObjectResponse xmlns:u="urn:schemas-upnp-org:service:ContentDirectory:1">
      <ObjectID>%(obj_id)s</ObjectID>
      <Result>%(didl)s</Result>
    </u:CreateObjectResponse>
  </s:Body>
</s:Envelope>'''

CREATE_OBJ_RESPONSE_DIDL = '''<DIDL-Lite xmlns="urn:schemas-upnp-org:metadata-1-0/DIDL-Lite/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:upnp='urn:schemas-upnp-org:metadata-1-0/upnp/' xmlns:dlna="urn:schemas-dlna-org:metadata-1-0/" xmlns:sec="http://www.sec.co.kr/">
  <item id="%(obj_id)s" parentID="%(parent_id)s" restricted="0" dlna:dlnaManaged="00000004">
    <dc:title></dc:title>
    <res protocolInfo="http-get:*:%(obj_type)s:%(obj_subtype)s;DLNA.ORG_CI=0;DLNA.ORG_FLAGS=00D00000000000000000000000000000" importUri="http://%(interface)s:52235/cd/content?didx=0_id=%(obj_id)s" dlna:resumeUpload="0" dlna:uploadedSize="0" size="%(obj_size)s"></res>
    <upnp:class>%(obj_class)s</upnp:class>
  </item>
</DIDL-Lite>'''

X_BACKUP_DONE = '"urn:schemas-upnp-org:service:ContentDirectory:1#X_BACKUP_DONE"'
X_BACKUP_START = '"urn:schemas-upnp-org:service:ContentDirectory:1#X_BACKUP_START"'

X_BACKUP_RESPONSE = '''<?xml version="1.0"?>
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
  <s:Body>
    <u:X_BACKUP_%sResponse xmlns:u="urn:schemas-upnp-org:service:ContentDirectory:1"/>
  </s:Body>
</s:Envelope>'''


class Backup(object):

  backup_objects = {}

  def __init__(self):
    self.logger = logging.getLogger('MediaServer.Backup')
    self.config = common.LoadOrCreateConfig()

  def _GenerateObjectID(self, obj_date, length=10):
    chars = string.letters + string.digits
    rand_chars = ''.join(random.choice(chars) for i in xrange(length))
    parent_id = 'UP_%s' % obj_date
    obj_id = '%s_%s' % (parent_id, rand_chars)
    return (parent_id, obj_id)

  def CreateObject(self, obj_class, obj_name, obj_date, obj_type, obj_size,
                   obj_subtype):
    (parent_id, obj_id) = self._GenerateObjectID(obj_date)
    self.logger.debug('Creating Backup Object for %s (type:%s size:%s)',
                      obj_name, obj_type, obj_size)
    self.backup_objects[obj_id] = {'obj_class': obj_class,
                                   'obj_date': obj_date,
                                   'obj_name': obj_name,
                                   'obj_size': obj_size,
                                   'obj_subtype': obj_subtype,
                                   'obj_type': obj_type,
                                   'parent_id': parent_id}
    return obj_id

  def FinishBackup(self):
    pass

  def GetObjectDetails(self, obj_id):
    return self.backup_objects.get(obj_id)

  def StartBackup(self):
    pass

  def WriteObject(self, obj_id, data):
    obj_details = self.GetObjectDetails(obj_id)

    obj_dir = [self.config.get('AUTOBACKUP', 'backup_dir')]

    if self.config.getboolean('AUTOBACKUP', 'create_date_subdir'):
      obj_dir.append(obj_details['obj_date'])

    obj_dir = os.path.join(*obj_dir)

    if not os.path.isdir(obj_dir):
      self.logger.info('Creating output dir %s', obj_dir)
      os.makedirs(obj_dir)

    obj_file = os.path.join(obj_dir, obj_details['obj_name'])

    self.logger.info('Saving %s to %s', obj_details['obj_name'], obj_dir)
    with open(obj_file, 'wb') as f:
      f.write(data)
    self.logger.info('%s saved successfully', obj_details['obj_name'])

    del(self.backup_objects[obj_id])


class MediaServer(Resource):

  clients = {}
  isLeaf = True

  def __init__(self):
    self.logger = logging.getLogger('MediaServer')
    self.config = common.LoadOrCreateConfig()

  def render_GET(self, request):
    self.logger.debug('[%s] GET request for %s', request.getClientIP(),
                      request.path)
    self.logger.debug('Request args for %s from %s: %s', request.path,
                      request.getClientIP(), request.args)
    self.logger.debug('Request headers for %s from %s: %s', request.path,
                      request.getClientIP(), request.args)

    if request.path == '/DMS/SamsungDmsDesc.xml':
      self.logger.info('New connection from %s (%s)', request.getClientIP(),
                       request.getHeader('user-agent'))
      self.clients[request.getClientIP()] = request.getHeader('user-agent')
      response = self.GetDMSDescriptionResponse()
    elif request.path.split('/')[-1] == 'ContentDirectory1.xml':
      with open(os.path.join('DMS', 'ContentDirectory1.xml'), 'r') as xml_data:
        response = xml_data.read()
    elif request.path.split('/')[-1] == 'ConnectionManager1.xml':
      with open(os.path.join('DMS', 'ConnectionManager1.xml'), 'r') as xml_data:
        response = xml_data.read()
    else:
      self.logger.error('Unhandled GET request from %s: %s',
                        request.getClientIP(), request.path)
      return NoResource()

    self.logger.debug('Response: %s', response)
    request.setHeader("Content-Type", "text/xml; charset=utf-8")
    return response.encode('utf-8')

  def render_POST(self, request):
    self.logger.debug('Request args for %s from %s: %s', request.path,
                      request.getClientIP(), request.args)
    self.logger.debug('Request headers for %s from %s: %s', request.path,
                      request.getClientIP(), request.args)

    if request.path == '/cd/content':
      response = self.ReceiveUpload(request)
    elif request.path == '/upnp/control/ContentDirectory1':
      response = self.GetContentDirectoryResponse(request)
    else:
      self.logger.error('Unhandled POST request from %s: %s',
                        request.getClientIP(), request.path)
      return NoResource()

    self.logger.debug('Sending response for %s to %s: %s', request.path,
                      request.getClientIP(), response)
    request.setHeader("Content-Type", "text/xml; charset=utf-8")
    return response.encode('utf-8')

  def GetContentDirectoryResponse(self, request):
    self.logger.debug('Request content for %s from %s: %s', request.path,
                      request.getClientIP(), request.content.read())
    request.content.seek(0)

    soapaction = request.getHeader('soapaction')

    if soapaction == X_BACKUP_START:
      self.logger.info('Starting backup for %s (%s)', request.getClientIP(),
                       self.clients[request.getClientIP()])
      response = X_BACKUP_RESPONSE % 'START'
    elif soapaction == CREATE_OBJ:
      soap_xml = request.content.read()

      m = CREATE_OBJ_DIDL.search(soap_xml)
      if m:
        parsed_data = self.ParseDIDL(m.group('didl'))

        obj_class = parsed_data.get('class')
        obj_date = parsed_data.get('date')
        obj_name = parsed_data.get('name')
        obj_size = parsed_data.get('size')

        try:
          obj_type = parsed_data.get('protocolInfo').split(':')[2]
          obj_subtype = parsed_data.get('protocolInfo').split(':')[3]
        except IndexError:
          self.logger.error('Invalid DIDL: %s', soap_xml)
          return NoResource()

        backup = Backup()
        obj_id = backup.CreateObject(obj_class, obj_name, obj_date, obj_type,
                                     obj_size, obj_subtype)
        obj_details = backup.GetObjectDetails(obj_id)

        self.logger.info('Ready to receive %s (%s size:%s)', obj_name, obj_type,
                         obj_size)

        response_dict = {
            'interface': self.config.get('AUTOBACKUP', 'default_interface'),
            'obj_class': obj_class,
            'obj_id': obj_id,
            'obj_size': obj_size,
            'obj_subtype': obj_subtype,
            'obj_type': obj_type,
            'parent_id': obj_details['parent_id']}

        didl = CREATE_OBJ_RESPONSE_DIDL % response_dict
        response_dict['didl'] = common.EscapeHTML(didl)
        response = CREATE_OBJ_RESPONSE % response_dict
    elif soapaction == X_BACKUP_DONE:
      self.logger.info('Backup complete for %s (%s)', request.getClientIP(),
                       self.clients[request.getClientIP()])
      response = X_BACKUP_RESPONSE % 'DONE'
    else:
      self.logger.error('Unhandled soapaction: %s', soapaction)
      return NoResource()

    return response

  def GetDMSDescriptionResponse(self):
    with open(os.path.join('DMS', 'SamsungDmsDesc.xml'), 'r') as dms_desc:
      response = dms_desc.read() % {
          'friendly_name': self.config.get('AUTOBACKUP', 'server_name'),
          'uuid': self.config.get('AUTOBACKUP', 'uuid')}

    return response

  def ParseDIDL(self, didl):
    #<DIDL-Lite xmlns="urn:schemas-upnp-org:metadata-1-0/DIDL-Lite/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:upnp="urn:schemas-upnp-org:metadata-1-0/upnp/" xmlns:dlna = "urn:schemas-dlna-org:metadata-1-0/">
    #  <item id="" restricted="0" parentID="DLNA.ORG_AnyContainer" >
    #    <dc:title>SAM_0001.JPG</dc:title>
    #    <dc:date>2012-01-01</dc:date>
    #    <upnp:class>object.item.imageItem</upnp:class>
    #    <res protocolInfo="*:*:image/jpeg:DLNA.ORG_PN=JPEG_LRG;DLNA.ORG_CI=0" size="4429673" ></res>
    #  </item>
    #</DIDL-Lite>
    parser = HTMLParser.HTMLParser()
    didl = parser.unescape(didl)

    didl_elements = {}
    dom = xml.dom.minidom.parseString(didl)

    def getText(node):
      rc = []
      for child in node.childNodes:
        if child.nodeType == child.TEXT_NODE:
          rc.append(child.data)
      return ''.join(rc)

    title = dom.getElementsByTagName('dc:title')
    if title:
      didl_elements['name'] = getText(title[0])

    date = dom.getElementsByTagName('dc:date')
    if date:
      didl_elements['date'] = getText(date[0])

    upnp_class = dom.getElementsByTagName('upnp:class')
    if upnp_class:
      didl_elements['class'] = getText(upnp_class[0])

    res = dom.getElementsByTagName('res')
    if res:
      for k, v in res[0].attributes.items():
        didl_elements[k] = v

    return didl_elements

  def ReceiveUpload(self, request):
    response = ''

    obj_id = request.args['didx'][0].split('=')[1]
    backup = Backup()

    data = request.content.read()
    backup.WriteObject(obj_id, data)

    return response


def StartMediaServer():
  logging.info('MediaServer started')
  resource = MediaServer()
  factory = Site(resource)
  reactor.listenTCP(52235, factory)
  reactor.run()


def main():
  logging_options = common.LOG_DEFAULTS
  logging_options['filename'] = 'mediaserver.log'
  logging_options['level'] = logging.DEBUG
  logging.basicConfig(**logging_options)
  StartMediaServer()


if __name__ == '__main__':
  main()