# Copyright 2018 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Unit tests."""

import pytest

from google.cloud import automl_v1beta1
from google.cloud.automl_v1beta1.proto import data_items_pb2
from google.cloud.automl_v1beta1.proto import prediction_service_pb2


class MultiCallableStub(object):
    """Stub for the grpc.UnaryUnaryMultiCallable interface."""

    def __init__(self, method, channel_stub):
        self.method = method
        self.channel_stub = channel_stub

    def __call__(self, request, timeout=None, metadata=None, credentials=None):
        self.channel_stub.requests.append((self.method, request))

        response = None
        if self.channel_stub.responses:
            response = self.channel_stub.responses.pop()

        if isinstance(response, Exception):
            raise response

        if response:
            return response


class ChannelStub(object):
    """Stub for the grpc.Channel interface."""

    def __init__(self, responses=[]):
        self.responses = responses
        self.requests = []

    def unary_unary(self,
                    method,
                    request_serializer=None,
                    response_deserializer=None):
        return MultiCallableStub(method, self)


class CustomException(Exception):
    pass


class TestPredictionServiceClient(object):
    def test_predict(self):
        # Setup Expected Response
        expected_response = {}
        expected_response = prediction_service_pb2.PredictResponse(
            **expected_response)

        # Mock the API response
        channel = ChannelStub(responses=[expected_response])
        client = automl_v1beta1.PredictionServiceClient(channel=channel)

        # Setup Request
        name = client.model_path('[PROJECT]', '[LOCATION]', '[MODEL]')
        payload = {}

        response = client.predict(name, payload)
        assert expected_response == response

        assert len(channel.requests) == 1
        expected_request = prediction_service_pb2.PredictRequest(
            name=name, payload=payload)
        actual_request = channel.requests[0][1]
        assert expected_request == actual_request

    def test_predict_exception(self):
        # Mock the API response
        channel = ChannelStub(responses=[CustomException()])
        client = automl_v1beta1.PredictionServiceClient(channel=channel)

        # Setup request
        name = client.model_path('[PROJECT]', '[LOCATION]', '[MODEL]')
        payload = {}

        with pytest.raises(CustomException):
            client.predict(name, payload)
