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"""A utility useful in tests of asynchronous, event-driven interfaces."""

import threading

from grpc.framework.interfaces.face import face


class Receiver(face.ResponseReceiver):
  """A utility object useful in tests of asynchronous code."""

  def __init__(self):
    self._condition = threading.Condition()
    self._initial_metadata = None
    self._responses = []
    self._terminal_metadata = None
    self._code = None
    self._details = None
    self._completed = False
    self._abortion = None

  def abort(self, abortion):
    with self._condition:
      self._abortion = abortion
      self._condition.notify_all()

  def initial_metadata(self, initial_metadata):
    with self._condition:
      self._initial_metadata = initial_metadata

  def response(self, response):
    with self._condition:
      self._responses.append(response)

  def complete(self, terminal_metadata, code, details):
    with self._condition:
      self._terminal_metadata = terminal_metadata
      self._code = code
      self._details = details
      self._completed = True
      self._condition.notify_all()

  def block_until_terminated(self):
    with self._condition:
      while self._abortion is None and not self._completed:
        self._condition.wait()

  def unary_response(self):
    with self._condition:
      if self._abortion is not None:
        raise AssertionError('Aborted: "{}"!'.format(self._abortion))
      elif len(self._responses) != 1:
        raise AssertionError(
            '%d responses received, not exactly one!', len(self._responses))
      else:
        return self._responses[0]

  def stream_responses(self):
    with self._condition:
      if self._abortion is None:
        return list(self._responses)
      else:
        raise AssertionError('Aborted: "{}"!'.format(self._abortion))

  def abortion(self):
    with self._condition:
      return self._abortion