# Copyright 2015, Google Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
#     * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
#     * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

"""Implementations of interoperability test methods."""

import enum
import json
import os
import threading
import time

from oauth2client import client as oauth2client_client

from grpc.framework.common import cardinality
from grpc.framework.interfaces.face import face

from tests.interop import empty_pb2
from tests.interop import messages_pb2
from tests.interop import test_pb2

_TIMEOUT = 7


class TestService(test_pb2.BetaTestServiceServicer):

  def EmptyCall(self, request, context):
    return empty_pb2.Empty()

  def UnaryCall(self, request, context):
    return messages_pb2.SimpleResponse(
        payload=messages_pb2.Payload(
            type=messages_pb2.COMPRESSABLE,
            body=b'\x00' * request.response_size))

  def StreamingOutputCall(self, request, context):
    for response_parameters in request.response_parameters:
      yield messages_pb2.StreamingOutputCallResponse(
          payload=messages_pb2.Payload(
              type=request.response_type,
              body=b'\x00' * response_parameters.size))

  def StreamingInputCall(self, request_iterator, context):
    aggregate_size = 0
    for request in request_iterator:
      if request.payload and request.payload.body:
        aggregate_size += len(request.payload.body)
    return messages_pb2.StreamingInputCallResponse(
        aggregated_payload_size=aggregate_size)

  def FullDuplexCall(self, request_iterator, context):
    for request in request_iterator:
      yield messages_pb2.StreamingOutputCallResponse(
          payload=messages_pb2.Payload(
              type=request.payload.type,
              body=b'\x00' * request.response_parameters[0].size))

  # NOTE(nathaniel): Apparently this is the same as the full-duplex call?
  # NOTE(atash): It isn't even called in the interop spec (Oct 22 2015)...
  def HalfDuplexCall(self, request_iterator, context):
    return self.FullDuplexCall(request_iterator, context)


def _large_unary_common_behavior(stub, fill_username, fill_oauth_scope):
  with stub:
    request = messages_pb2.SimpleRequest(
        response_type=messages_pb2.COMPRESSABLE, response_size=314159,
        payload=messages_pb2.Payload(body=b'\x00' * 271828),
        fill_username=fill_username, fill_oauth_scope=fill_oauth_scope)
    response_future = stub.UnaryCall.future(request, _TIMEOUT)
    response = response_future.result()
    if response.payload.type is not messages_pb2.COMPRESSABLE:
      raise ValueError(
          'response payload type is "%s"!' % type(response.payload.type))
    if len(response.payload.body) != 314159:
      raise ValueError(
          'response body of incorrect size %d!' % len(response.payload.body))
    return response


def _empty_unary(stub):
  with stub:
    response = stub.EmptyCall(empty_pb2.Empty(), _TIMEOUT)
    if not isinstance(response, empty_pb2.Empty):
      raise TypeError(
          'response is of type "%s", not empty_pb2.Empty!', type(response))


def _large_unary(stub):
  _large_unary_common_behavior(stub, False, False)


def _client_streaming(stub):
  with stub:
    payload_body_sizes = (27182, 8, 1828, 45904)
    payloads = (
        messages_pb2.Payload(body=b'\x00' * size)
        for size in payload_body_sizes)
    requests = (
        messages_pb2.StreamingInputCallRequest(payload=payload)
        for payload in payloads)
    response = stub.StreamingInputCall(requests, _TIMEOUT)
    if response.aggregated_payload_size != 74922:
      raise ValueError(
          'incorrect size %d!' % response.aggregated_payload_size)


def _server_streaming(stub):
  sizes = (31415, 9, 2653, 58979)

  with stub:
    request = messages_pb2.StreamingOutputCallRequest(
        response_type=messages_pb2.COMPRESSABLE,
        response_parameters=(
            messages_pb2.ResponseParameters(size=sizes[0]),
            messages_pb2.ResponseParameters(size=sizes[1]),
            messages_pb2.ResponseParameters(size=sizes[2]),
            messages_pb2.ResponseParameters(size=sizes[3]),
        ))
    response_iterator = stub.StreamingOutputCall(request, _TIMEOUT)
    for index, response in enumerate(response_iterator):
      if response.payload.type != messages_pb2.COMPRESSABLE:
        raise ValueError(
            'response body of invalid type %s!' % response.payload.type)
      if len(response.payload.body) != sizes[index]:
        raise ValueError(
            'response body of invalid size %d!' % len(response.payload.body))

def _cancel_after_begin(stub):
  with stub:
    sizes = (27182, 8, 1828, 45904)
    payloads = [messages_pb2.Payload(body=b'\x00' * size) for size in sizes]
    requests = [messages_pb2.StreamingInputCallRequest(payload=payload)
                for payload in payloads]
    responses = stub.StreamingInputCall.future(requests, _TIMEOUT)
    responses.cancel()
    if not responses.cancelled():
      raise ValueError('expected call to be cancelled')


class _Pipe(object):

  def __init__(self):
    self._condition = threading.Condition()
    self._values = []
    self._open = True

  def __iter__(self):
    return self

  def next(self):
    with self._condition:
      while not self._values and self._open:
        self._condition.wait()
      if self._values:
        return self._values.pop(0)
      else:
        raise StopIteration()

  def add(self, value):
    with self._condition:
      self._values.append(value)
      self._condition.notify()

  def close(self):
    with self._condition:
      self._open = False
      self._condition.notify()

  def __enter__(self):
    return self

  def __exit__(self, type, value, traceback):
    self.close()


def _ping_pong(stub):
  request_response_sizes = (31415, 9, 2653, 58979)
  request_payload_sizes = (27182, 8, 1828, 45904)

  with stub, _Pipe() as pipe:
    response_iterator = stub.FullDuplexCall(pipe, _TIMEOUT)
    print 'Starting ping-pong with response iterator %s' % response_iterator
    for response_size, payload_size in zip(
        request_response_sizes, request_payload_sizes):
      request = messages_pb2.StreamingOutputCallRequest(
          response_type=messages_pb2.COMPRESSABLE,
          response_parameters=(messages_pb2.ResponseParameters(
              size=response_size),),
          payload=messages_pb2.Payload(body=b'\x00' * payload_size))
      pipe.add(request)
      response = next(response_iterator)
      if response.payload.type != messages_pb2.COMPRESSABLE:
        raise ValueError(
            'response body of invalid type %s!' % response.payload.type)
      if len(response.payload.body) != response_size:
        raise ValueError(
            'response body of invalid size %d!' % len(response.payload.body))


def _cancel_after_first_response(stub):
  request_response_sizes = (31415, 9, 2653, 58979)
  request_payload_sizes = (27182, 8, 1828, 45904)
  with stub, _Pipe() as pipe:
    response_iterator = stub.FullDuplexCall(pipe, _TIMEOUT)

    response_size = request_response_sizes[0]
    payload_size = request_payload_sizes[0]
    request = messages_pb2.StreamingOutputCallRequest(
        response_type=messages_pb2.COMPRESSABLE,
        response_parameters=(messages_pb2.ResponseParameters(
            size=response_size),),
        payload=messages_pb2.Payload(body=b'\x00' * payload_size))
    pipe.add(request)
    response = next(response_iterator)
    # We test the contents of `response` in the Ping Pong test - don't check
    # them here.
    response_iterator.cancel()

    try:
      next(response_iterator)
    except Exception:
      pass
    else:
      raise ValueError('expected call to be cancelled')


def _timeout_on_sleeping_server(stub):
  request_payload_size = 27182
  with stub, _Pipe() as pipe:
    response_iterator = stub.FullDuplexCall(pipe, 0.001)

    request = messages_pb2.StreamingOutputCallRequest(
        response_type=messages_pb2.COMPRESSABLE,
        payload=messages_pb2.Payload(body=b'\x00' * request_payload_size))
    pipe.add(request)
    time.sleep(0.1)
    try:
      next(response_iterator)
    except face.ExpirationError:
      pass
    else:
      raise ValueError('expected call to exceed deadline')


def _empty_stream(stub):
  with stub, _Pipe() as pipe:
    response_iterator = stub.FullDuplexCall(pipe, _TIMEOUT)
    pipe.close()
    try:
      next(response_iterator)
      raise ValueError('expected exactly 0 responses')
    except StopIteration:
      pass


def _compute_engine_creds(stub, args):
  response = _large_unary_common_behavior(stub, True, True)
  if args.default_service_account != response.username:
    raise ValueError(
        'expected username %s, got %s' % (args.default_service_account,
                                          response.username))


def _oauth2_auth_token(stub, args):
  json_key_filename = os.environ[
      oauth2client_client.GOOGLE_APPLICATION_CREDENTIALS]
  wanted_email = json.load(open(json_key_filename, 'rb'))['client_email']
  response = _large_unary_common_behavior(stub, True, True)
  if wanted_email != response.username:
    raise ValueError(
        'expected username %s, got %s' % (wanted_email, response.username))
  if args.oauth_scope.find(response.oauth_scope) == -1:
    raise ValueError(
        'expected to find oauth scope "%s" in received "%s"' %
            (response.oauth_scope, args.oauth_scope))

@enum.unique
class TestCase(enum.Enum):
  EMPTY_UNARY = 'empty_unary'
  LARGE_UNARY = 'large_unary'
  SERVER_STREAMING = 'server_streaming'
  CLIENT_STREAMING = 'client_streaming'
  PING_PONG = 'ping_pong'
  CANCEL_AFTER_BEGIN = 'cancel_after_begin'
  CANCEL_AFTER_FIRST_RESPONSE = 'cancel_after_first_response'
  EMPTY_STREAM = 'empty_stream'
  COMPUTE_ENGINE_CREDS = 'compute_engine_creds'
  OAUTH2_AUTH_TOKEN = 'oauth2_auth_token'
  TIMEOUT_ON_SLEEPING_SERVER = 'timeout_on_sleeping_server'

  def test_interoperability(self, stub, args):
    if self is TestCase.EMPTY_UNARY:
      _empty_unary(stub)
    elif self is TestCase.LARGE_UNARY:
      _large_unary(stub)
    elif self is TestCase.SERVER_STREAMING:
      _server_streaming(stub)
    elif self is TestCase.CLIENT_STREAMING:
      _client_streaming(stub)
    elif self is TestCase.PING_PONG:
      _ping_pong(stub)
    elif self is TestCase.CANCEL_AFTER_BEGIN:
      _cancel_after_begin(stub)
    elif self is TestCase.CANCEL_AFTER_FIRST_RESPONSE:
      _cancel_after_first_response(stub)
    elif self is TestCase.TIMEOUT_ON_SLEEPING_SERVER:
      _timeout_on_sleeping_server(stub)
    elif self is TestCase.EMPTY_STREAM:
      _empty_stream(stub)
    elif self is TestCase.COMPUTE_ENGINE_CREDS:
      _compute_engine_creds(stub, args)
    elif self is TestCase.OAUTH2_AUTH_TOKEN:
      _oauth2_auth_token(stub, args)
    else:
      raise NotImplementedError('Test case "%s" not implemented!' % self.name)
