# Copyright 2017 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
#
#     http://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.

import grpc
import mock
import pytest

from google.api_core import exceptions
from google.api_core import grpc_helpers
import google.auth.credentials
from google.longrunning import operations_pb2


def test__patch_callable_name():
    callable = mock.Mock(spec=['__class__'])
    callable.__class__ = mock.Mock(spec=['__name__'])
    callable.__class__.__name__ = 'TestCallable'

    grpc_helpers._patch_callable_name(callable)

    assert callable.__name__ == 'TestCallable'


def test__patch_callable_name_no_op():
    callable = mock.Mock(spec=['__name__'])
    callable.__name__ = 'test_callable'

    grpc_helpers._patch_callable_name(callable)

    assert callable.__name__ == 'test_callable'


class RpcErrorImpl(grpc.RpcError, grpc.Call):
    def __init__(self, code):
        super(RpcErrorImpl, self).__init__()
        self._code = code

    def code(self):
        return self._code

    def details(self):
        return None


def test_wrap_unary_errors():
    grpc_error = RpcErrorImpl(grpc.StatusCode.INVALID_ARGUMENT)
    callable_ = mock.Mock(spec=['__call__'], side_effect=grpc_error)

    wrapped_callable = grpc_helpers._wrap_unary_errors(callable_)

    with pytest.raises(exceptions.InvalidArgument) as exc_info:
        wrapped_callable(1, 2, three='four')

    callable_.assert_called_once_with(1, 2, three='four')
    assert exc_info.value.response == grpc_error


def test_wrap_stream_errors_invocation():
    grpc_error = RpcErrorImpl(grpc.StatusCode.INVALID_ARGUMENT)
    callable_ = mock.Mock(spec=['__call__'], side_effect=grpc_error)

    wrapped_callable = grpc_helpers._wrap_stream_errors(callable_)

    with pytest.raises(exceptions.InvalidArgument) as exc_info:
        wrapped_callable(1, 2, three='four')

    callable_.assert_called_once_with(1, 2, three='four')
    assert exc_info.value.response == grpc_error


class RpcResponseIteratorImpl(object):
    def __init__(self, exception):
        self._exception = exception

    # Note: This matches grpc._channel._Rendezvous._next which is what is
    # patched by _wrap_stream_errors.
    def _next(self):
        raise self._exception

    def __next__(self):  # pragma: NO COVER
        return self._next()

    def next(self):  # pragma: NO COVER
        return self._next()


def test_wrap_stream_errors_iterator():
    grpc_error = RpcErrorImpl(grpc.StatusCode.UNAVAILABLE)
    response_iter = RpcResponseIteratorImpl(grpc_error)
    callable_ = mock.Mock(spec=['__call__'], return_value=response_iter)

    wrapped_callable = grpc_helpers._wrap_stream_errors(callable_)

    got_iterator = wrapped_callable(1, 2, three='four')

    with pytest.raises(exceptions.ServiceUnavailable) as exc_info:
        next(got_iterator)

    assert got_iterator == response_iter
    callable_.assert_called_once_with(1, 2, three='four')
    assert exc_info.value.response == grpc_error


@mock.patch('google.api_core.grpc_helpers._wrap_unary_errors')
def test_wrap_errors_non_streaming(wrap_unary_errors):
    callable_ = mock.create_autospec(grpc.UnaryUnaryMultiCallable)

    result = grpc_helpers.wrap_errors(callable_)

    assert result == wrap_unary_errors.return_value
    wrap_unary_errors.assert_called_once_with(callable_)


@mock.patch('google.api_core.grpc_helpers._wrap_stream_errors')
def test_wrap_errors_streaming(wrap_stream_errors):
    callable_ = mock.create_autospec(grpc.UnaryStreamMultiCallable)

    result = grpc_helpers.wrap_errors(callable_)

    assert result == wrap_stream_errors.return_value
    wrap_stream_errors.assert_called_once_with(callable_)


@mock.patch(
    'google.auth.default',
    return_value=(mock.sentinel.credentials, mock.sentinel.projet))
@mock.patch('google.auth.transport.grpc.secure_authorized_channel')
def test_create_channel_implicit(secure_authorized_channel, default):
    target = 'example.com:443'

    channel = grpc_helpers.create_channel(target)

    assert channel is secure_authorized_channel.return_value
    default.assert_called_once_with(scopes=None)
    secure_authorized_channel.assert_called_once_with(
        mock.sentinel.credentials, mock.ANY, target)


@mock.patch(
    'google.auth.default',
    return_value=(mock.sentinel.credentials, mock.sentinel.projet))
@mock.patch('google.auth.transport.grpc.secure_authorized_channel')
def test_create_channel_implicit_with_scopes(
        secure_authorized_channel, default):
    target = 'example.com:443'

    channel = grpc_helpers.create_channel(target, scopes=['one', 'two'])

    assert channel is secure_authorized_channel.return_value
    default.assert_called_once_with(scopes=['one', 'two'])


@mock.patch('google.auth.transport.grpc.secure_authorized_channel')
def test_create_channel_explicit(secure_authorized_channel):
    target = 'example.com:443'

    channel = grpc_helpers.create_channel(
        target, credentials=mock.sentinel.credentials)

    assert channel is secure_authorized_channel.return_value
    secure_authorized_channel.assert_called_once_with(
        mock.sentinel.credentials, mock.ANY, target)


@mock.patch('google.auth.transport.grpc.secure_authorized_channel')
def test_create_channel_explicit_scoped(unused_secure_authorized_channel):
    scopes = ['1', '2']

    credentials = mock.create_autospec(
        google.auth.credentials.Scoped, instance=True)
    credentials.requires_scopes = True

    grpc_helpers.create_channel(
        mock.sentinel.target,
        credentials=credentials,
        scopes=scopes)

    credentials.with_scopes.assert_called_once_with(scopes)


class TestChannelStub(object):

    def test_single_response(self):
        channel = grpc_helpers.ChannelStub()
        stub = operations_pb2.OperationsStub(channel)
        expected_request = operations_pb2.GetOperationRequest(name='meep')
        expected_response = operations_pb2.Operation(name='moop')

        channel.GetOperation.response = expected_response

        response = stub.GetOperation(expected_request)

        assert response == expected_response
        assert channel.requests == [('GetOperation', expected_request)]
        assert channel.GetOperation.requests == [expected_request]

    def test_no_response(self):
        channel = grpc_helpers.ChannelStub()
        stub = operations_pb2.OperationsStub(channel)
        expected_request = operations_pb2.GetOperationRequest(name='meep')

        with pytest.raises(ValueError) as exc_info:
            stub.GetOperation(expected_request)

        assert exc_info.match('GetOperation')

    def test_missing_method(self):
        channel = grpc_helpers.ChannelStub()

        with pytest.raises(AttributeError):
            channel.DoesNotExist.response

    def test_exception_response(self):
        channel = grpc_helpers.ChannelStub()
        stub = operations_pb2.OperationsStub(channel)
        expected_request = operations_pb2.GetOperationRequest(name='meep')

        channel.GetOperation.response = RuntimeError()

        with pytest.raises(RuntimeError):
            stub.GetOperation(expected_request)

    def test_callable_response(self):
        channel = grpc_helpers.ChannelStub()
        stub = operations_pb2.OperationsStub(channel)
        expected_request = operations_pb2.GetOperationRequest(name='meep')
        expected_response = operations_pb2.Operation(name='moop')

        on_get_operation = mock.Mock(
            spec=('__call__',), return_value=expected_response)

        channel.GetOperation.response = on_get_operation

        response = stub.GetOperation(expected_request)

        assert response == expected_response
        on_get_operation.assert_called_once_with(expected_request)

    def test_multiple_responses(self):
        channel = grpc_helpers.ChannelStub()
        stub = operations_pb2.OperationsStub(channel)
        expected_request = operations_pb2.GetOperationRequest(name='meep')
        expected_responses = [
            operations_pb2.Operation(name='foo'),
            operations_pb2.Operation(name='bar'),
            operations_pb2.Operation(name='baz'),
        ]

        channel.GetOperation.responses = iter(expected_responses)

        response1 = stub.GetOperation(expected_request)
        response2 = stub.GetOperation(expected_request)
        response3 = stub.GetOperation(expected_request)

        assert response1 == expected_responses[0]
        assert response2 == expected_responses[1]
        assert response3 == expected_responses[2]
        assert channel.requests == [('GetOperation', expected_request)] * 3
        assert channel.GetOperation.requests == [expected_request] * 3

        with pytest.raises(StopIteration):
            stub.GetOperation(expected_request)

    def test_multiple_responses_and_single_response_error(self):
        channel = grpc_helpers.ChannelStub()
        stub = operations_pb2.OperationsStub(channel)
        channel.GetOperation.responses = []
        channel.GetOperation.response = mock.sentinel.response

        with pytest.raises(ValueError):
            stub.GetOperation(operations_pb2.GetOperationRequest())

    def test_call_info(self):
        channel = grpc_helpers.ChannelStub()
        stub = operations_pb2.OperationsStub(channel)
        expected_request = operations_pb2.GetOperationRequest(name='meep')
        expected_response = operations_pb2.Operation(name='moop')
        expected_metadata = [('red', 'blue'), ('two', 'shoe')]
        expected_credentials = mock.sentinel.credentials
        channel.GetOperation.response = expected_response

        response = stub.GetOperation(
            expected_request, timeout=42, metadata=expected_metadata,
            credentials=expected_credentials)

        assert response == expected_response
        assert channel.requests == [('GetOperation', expected_request)]
        assert channel.GetOperation.calls == [
            (expected_request, 42, expected_metadata, expected_credentials)]

    def test_unary_unary(self):
        channel = grpc_helpers.ChannelStub()
        method_name = 'GetOperation'
        callable_stub = channel.unary_unary(method_name)
        assert callable_stub._method == method_name
        assert callable_stub._channel == channel

    def test_unary_stream(self):
        channel = grpc_helpers.ChannelStub()
        method_name = 'GetOperation'
        callable_stub = channel.unary_stream(method_name)
        assert callable_stub._method == method_name
        assert callable_stub._channel == channel

    def test_stream_unary(self):
        channel = grpc_helpers.ChannelStub()
        method_name = 'GetOperation'
        callable_stub = channel.stream_unary(method_name)
        assert callable_stub._method == method_name
        assert callable_stub._channel == channel

    def test_stream_stream(self):
        channel = grpc_helpers.ChannelStub()
        method_name = 'GetOperation'
        callable_stub = channel.stream_stream(method_name)
        assert callable_stub._method == method_name
        assert callable_stub._channel == channel

    def test_subscribe_unsubscribe(self):
        channel = grpc_helpers.ChannelStub()
        assert channel.subscribe(None) is None
        assert channel.unsubscribe(None) is None
