text: # -*- coding: utf-8 -*-
  
  """
  The MIT License (MIT)
  
  Copyright (c) 2015-2016 Rapptz
  
  Permission is hereby granted, free of charge, to any person obtaining a
  copy of this software and associated documentation files (the "Software"),
  to deal in the Software without restriction, including without limitation
  the rights to use, copy, modify, merge, publish, distribute, sublicense,
  and/or sell copies of the Software, and to permit persons to whom the
  Software is furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  DEALINGS IN THE SOFTWARE.
  """
  
  import sys
  import asyncio
  import aiohttp
  from .message import Message
  from .object import Object
  
  PY35 = sys.version_info >= (3, 5)
  
  
  class LogsFromIterator:
      """Iterator for recieving logs.
  
      The messages endpoint has two behaviors we care about here:
      If `before` is specified, the messages endpoint returns the `limit`
      newest messages before `before`, sorted with newest first. For filling over
      100 messages, update the `before` parameter to the oldest message recieved.
      Messages will be returned in order by time.
      If `after` is specified, it returns the `limit` oldest messages after
      `after`, sorted with newest first. For filling over 100 messages, update the
      `after` parameter to the newest message recieved. If messages are not
      reversed, they will be out of order (99-0, 199-100, so on)
  
      A note that if both before and after are specified, before is ignored by the
      messages endpoint.
  
      Parameters
      -----------
      client : class:`Client`
      channel : class:`Channel`
          Channel from which to request logs
      limit : int
          Maximum number of messages to retrieve
      before : :class:`Message` or id-like
          Message before which all messages must be.
      after : :class:`Message` or id-like
          Message after which all messages must be.
      around : :class:`Message` or id-like
          Message around which all messages must be. Limit max 101. Note that if
          limit is an even number, this will return at most limit+1 messages.
      reverse : bool
          If set to true, return messages in oldest->newest order. Recommended
          when using with "after" queries with limit over 100, otherwise messages
          will be out of order. Defaults to False for backwards compatability.
      """
  
      def __init__(self, client, channel, limit,
                   before=None, after=None, around=None, reverse=False):
          self.client = client
          self.connection = client.connection
          self.channel = channel
          self.limit = limit
          self.before = before
          self.after = after
          self.around = around
          self.reverse = reverse
          self._filter = None  # message dict -> bool
          self.messages = asyncio.Queue()
  
          if self.around:
              if self.limit > 101:
                  raise ValueError("LogsFrom max limit 101 when specifying around parameter")
              elif self.limit == 101:
                  self.limit = 100  # Thanks discord
              elif self.limit == 1:
                  raise ValueError("Use get_message.")
  
              self._retrieve_messages = self._retrieve_messages_around_strategy
              if self.before and self.after:
                  self._filter = lambda m: int(self.after.id) < int(m['id']) < int(self.before.id)
              elif self.before:
                  self._filter = lambda m: int(m['id']) < int(self.before.id)
              elif self.after:
                  self._filter = lambda m: int(self.after.id) < int(m['id'])
          elif self.before and self.after:
              if self.reverse:
                  self._retrieve_messages = self._retrieve_messages_after_strategy
                  self._filter = lambda m: int(m['id']) < int(self.before.id)
              else:
                  self._retrieve_messages = self._retrieve_messages_before_strategy
                  self._filter = lambda m: int(m['id']) > int(self.after.id)
          elif self.after:
              self._retrieve_messages = self._retrieve_messages_after_strategy
          else:
              self._retrieve_messages = self._retrieve_messages_before_strategy
  
      @asyncio.coroutine
      def iterate(self):
          if self.messages.empty():
              yield from self.fill_messages()
  
          return self.messages.get_nowait()
  
      @asyncio.coroutine
      def fill_messages(self):
          if self.limit > 0:
              retrieve = self.limit if self.limit <= 100 else 100
              data = yield from self._retrieve_messages(retrieve)
              if self.reverse:
                  data = reversed(data)
              if self._filter:
                  data = filter(self._filter, data)
              for element in data:
                  yield from self.messages.put(
                      self.connection._create_message(
                          channel=self.channel, **element))
  
      @asyncio.coroutine
      def _retrieve_messages(self, retrieve):
          """Retrieve messages and update next parameters."""
          pass
  
      @asyncio.coroutine
      def _retrieve_messages_before_strategy(self, retrieve):
          """Retrieve messages using before parameter."""
          data = yield from self.client._logs_from(self.channel, retrieve, before=self.before)
          if len(data):
              self.limit -= retrieve
              self.before = Object(id=data[-1]['id'])
          return data
  
      @asyncio.coroutine
      def _retrieve_messages_after_strategy(self, retrieve):
          """Retrieve messages using after parameter."""
          data = yield from self.client._logs_from(self.channel, retrieve, after=self.after)
          if len(data):
              self.limit -= retrieve
              self.after = Object(id=data[0]['id'])
          return data
  
      @asyncio.coroutine
      def _retrieve_messages_around_strategy(self, retrieve):
          """Retrieve messages using around parameter."""
          if self.around:
              data = yield from self.client._logs_from(self.channel, retrieve, around=self.around)
              self.around = None
              return data
          return []
  
      if PY35:
          @asyncio.coroutine
          def __aiter__(self):
              return self
  
          @asyncio.coroutine
          def __anext__(self):
              try:
                  msg = yield from self.iterate()
                  return msg
              except asyncio.QueueEmpty:
                  # if we're still empty at this point...
                  # we didn't get any new messages so stop looping
                  raise StopAsyncIteration()
  