# -*- coding: utf-8 -*-
# Copyright 2020 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 abc
import re
from typing import Awaitable, Callable, Optional, Sequence, Union

import google.api_core  # type: ignore
from google.api_core import exceptions as core_exceptions  # type: ignore
from google.api_core import gapic_v1  # type: ignore
from google.api_core import retry as retries  # type: ignore
from google.api_core import version
import google.auth  # type: ignore
from google.auth import credentials as ga_credentials  # type: ignore
from google.longrunning import operations_pb2
from google.oauth2 import service_account  # type: ignore
import google.protobuf
from google.protobuf import empty_pb2, json_format  # type: ignore
from grpc import Compression


PROTOBUF_VERSION = google.protobuf.__version__

DEFAULT_CLIENT_INFO = gapic_v1.client_info.ClientInfo(
    gapic_version=version.__version__,
)


class OperationsTransport(abc.ABC):
    """Abstract transport class for Operations."""

    AUTH_SCOPES = ()

    DEFAULT_HOST: str = "longrunning.googleapis.com"

    def __init__(
        self,
        *,
        host: str = DEFAULT_HOST,
        # TODO(https://github.com/googleapis/python-api-core/issues/709): update type hint for credentials to include `google.auth.aio.Credentials`.
        credentials: Optional[ga_credentials.Credentials] = None,
        credentials_file: Optional[str] = None,
        scopes: Optional[Sequence[str]] = None,
        quota_project_id: Optional[str] = None,
        client_info: gapic_v1.client_info.ClientInfo = DEFAULT_CLIENT_INFO,
        always_use_jwt_access: Optional[bool] = False,
        url_scheme="https",
        **kwargs,
    ) -> None:
        """Instantiate the transport.

        Args:
            host (Optional[str]):
                 The hostname to connect to.
            credentials (Optional[google.auth.credentials.Credentials]): The
                authorization credentials to attach to requests. These
                credentials identify the application to the service; if none
                are specified, the client will attempt to ascertain the
                credentials from the environment.
            credentials_file (Optional[str]): A file with credentials that can
                be loaded with :func:`google.auth.load_credentials_from_file`.
                This argument is mutually exclusive with credentials.
            scopes (Optional[Sequence[str]]): A list of scopes.
            quota_project_id (Optional[str]): An optional project to use for billing
                and quota.
            client_info (google.api_core.gapic_v1.client_info.ClientInfo):
                The client info used to send a user-agent string along with
                API requests. If ``None``, then default info will be used.
                Generally, you only need to set this if you're developing
                your own client library.
            always_use_jwt_access (Optional[bool]): Whether self signed JWT should
                be used for service account credentials.
            url_scheme: the protocol scheme for the API endpoint.  Normally
                "https", but for testing or local servers,
                "http" can be specified.
        """
        maybe_url_match = re.match("^(?P<scheme>http(?:s)?://)?(?P<host>.*)$", host)
        if maybe_url_match is None:
            raise ValueError(
                f"Unexpected hostname structure: {host}"
            )  # pragma: NO COVER

        url_match_items = maybe_url_match.groupdict()

        host = f"{url_scheme}://{host}" if not url_match_items["scheme"] else host

        # Save the hostname. Default to port 443 (HTTPS) if none is specified.
        if ":" not in host:
            host += ":443"  # pragma: NO COVER
        self._host = host

        scopes_kwargs = {"scopes": scopes, "default_scopes": self.AUTH_SCOPES}

        # Save the scopes.
        self._scopes = scopes

        # If no credentials are provided, then determine the appropriate
        # defaults.
        if credentials and credentials_file:
            raise core_exceptions.DuplicateCredentialArgs(
                "'credentials_file' and 'credentials' are mutually exclusive"
            )

        if credentials_file is not None:
            credentials, _ = google.auth.load_credentials_from_file(
                credentials_file, **scopes_kwargs, quota_project_id=quota_project_id
            )

        elif credentials is None:
            credentials, _ = google.auth.default(
                **scopes_kwargs, quota_project_id=quota_project_id
            )

        # If the credentials are service account credentials, then always try to use self signed JWT.
        if (
            always_use_jwt_access
            and isinstance(credentials, service_account.Credentials)
            and hasattr(service_account.Credentials, "with_always_use_jwt_access")
        ):
            credentials = credentials.with_always_use_jwt_access(True)

        # Save the credentials.
        self._credentials = credentials

    def _prep_wrapped_messages(self, client_info):
        # Precompute the wrapped methods.
        self._wrapped_methods = {
            self.list_operations: gapic_v1.method.wrap_method(
                self.list_operations,
                default_retry=retries.Retry(
                    initial=0.5,
                    maximum=10.0,
                    multiplier=2.0,
                    predicate=retries.if_exception_type(
                        core_exceptions.ServiceUnavailable,
                    ),
                    deadline=10.0,
                ),
                default_timeout=10.0,
                default_compression=Compression.NoCompression,
                client_info=client_info,
            ),
            self.get_operation: gapic_v1.method.wrap_method(
                self.get_operation,
                default_retry=retries.Retry(
                    initial=0.5,
                    maximum=10.0,
                    multiplier=2.0,
                    predicate=retries.if_exception_type(
                        core_exceptions.ServiceUnavailable,
                    ),
                    deadline=10.0,
                ),
                default_timeout=10.0,
                default_compression=Compression.NoCompression,
                client_info=client_info,
            ),
            self.delete_operation: gapic_v1.method.wrap_method(
                self.delete_operation,
                default_retry=retries.Retry(
                    initial=0.5,
                    maximum=10.0,
                    multiplier=2.0,
                    predicate=retries.if_exception_type(
                        core_exceptions.ServiceUnavailable,
                    ),
                    deadline=10.0,
                ),
                default_timeout=10.0,
                default_compression=Compression.NoCompression,
                client_info=client_info,
            ),
            self.cancel_operation: gapic_v1.method.wrap_method(
                self.cancel_operation,
                default_retry=retries.Retry(
                    initial=0.5,
                    maximum=10.0,
                    multiplier=2.0,
                    predicate=retries.if_exception_type(
                        core_exceptions.ServiceUnavailable,
                    ),
                    deadline=10.0,
                ),
                default_timeout=10.0,
                default_compression=Compression.NoCompression,
                client_info=client_info,
            ),
        }

    def close(self):
        """Closes resources associated with the transport.

        .. warning::
             Only call this method if the transport is NOT shared
             with other clients - this may cause errors in other clients!
        """
        raise NotImplementedError()

    def _convert_protobuf_message_to_dict(
        self, message: google.protobuf.message.Message
    ):
        r"""Converts protobuf message to a dictionary.

        When the dictionary is encoded to JSON, it conforms to proto3 JSON spec.

        Args:
            message(google.protobuf.message.Message): The protocol buffers message
                instance to serialize.

        Returns:
            A dict representation of the protocol buffer message.
        """
        # TODO(https://github.com/googleapis/python-api-core/issues/643): For backwards compatibility
        # with protobuf 3.x 4.x, Remove once support for protobuf 3.x and 4.x is dropped.
        if PROTOBUF_VERSION[0:2] in ["3.", "4."]:
            result = json_format.MessageToDict(
                message,
                preserving_proto_field_name=True,
                including_default_value_fields=True,  # type: ignore # backward compatibility
            )
        else:
            result = json_format.MessageToDict(
                message,
                preserving_proto_field_name=True,
                always_print_fields_with_no_presence=True,
            )

        return result

    @property
    def list_operations(
        self,
    ) -> Callable[
        [operations_pb2.ListOperationsRequest],
        Union[
            operations_pb2.ListOperationsResponse,
            Awaitable[operations_pb2.ListOperationsResponse],
        ],
    ]:
        raise NotImplementedError()

    @property
    def get_operation(
        self,
    ) -> Callable[
        [operations_pb2.GetOperationRequest],
        Union[operations_pb2.Operation, Awaitable[operations_pb2.Operation]],
    ]:
        raise NotImplementedError()

    @property
    def delete_operation(
        self,
    ) -> Callable[
        [operations_pb2.DeleteOperationRequest],
        Union[empty_pb2.Empty, Awaitable[empty_pb2.Empty]],
    ]:
        raise NotImplementedError()

    @property
    def cancel_operation(
        self,
    ) -> Callable[
        [operations_pb2.CancelOperationRequest],
        Union[empty_pb2.Empty, Awaitable[empty_pb2.Empty]],
    ]:
        raise NotImplementedError()


__all__ = ("OperationsTransport",)
