import json
import logging

from multiprocessing import Process, Queue
from mixpanel import Consumer, Mixpanel


logger = logging.getLogger(__name__)


class MixpanelQueingConsumer(object):
  def __init__(self, request_queue):
    self._mp_queue = request_queue

  def send(self, endpoint, json_message):
    logger.debug('Queing mixpanel request.')
    self._mp_queue.put(json.dumps([endpoint, json_message]))


class SendToMixpanel(Process):
  def __init__(self, request_queue):
    Process.__init__(self)

    self._mp_queue = request_queue
    self._consumer = Consumer()
    self.daemon = True

  def run(self):
    logger.debug('Starting mixpanel sender process.')
    while True:
      mp_request = self._mp_queue.get()
      logger.debug('Got queued mixpanel reqeust.')
      try:
        self._consumer.send(*json.loads(mp_request))
      except:
        # Make sure we don't crash if Mixpanel request fails.
        pass


class FakeMixpanel(object):
  def track(*args, **kwargs):
    pass


class Analytics(object):
  def __init__(self, app=None):
    self.app = app
    if app is not None:
      self.state = self.init_app(app)
    else:
      self.state = None

  def init_app(self, app):
    analytics_type = app.config.get('ANALYTICS_TYPE', 'FakeAnalytics')

    if analytics_type == 'Mixpanel':
      mixpanel_key = app.config.get('MIXPANEL_KEY', '')
      logger.debug('Initializing mixpanel with key: %s' %
                   app.config['MIXPANEL_KEY'])

      request_queue = Queue()
      analytics = Mixpanel(mixpanel_key, MixpanelQueingConsumer(request_queue))
      SendToMixpanel(request_queue).start()

    else:
      analytics = FakeMixpanel()

    # register extension with app
    app.extensions = getattr(app, 'extensions', {})
    app.extensions['analytics'] = analytics
    return analytics

  def __getattr__(self, name):
    return getattr(self.state, name, None)