# Copyright 2019 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.

"""Client options class.

Client options provide a consistent interface for user options to be defined
across clients.

You can pass a client options object to a client.

.. code-block:: python

    from google.api_core.client_options import ClientOptions
    from google.cloud.vision_v1 import ImageAnnotatorClient

    def get_client_cert():
        # code to load client certificate and private key.
        return client_cert_bytes, client_private_key_bytes

    options = ClientOptions(api_endpoint="foo.googleapis.com",
        client_cert_source=get_client_cert)

    client = ImageAnnotatorClient(client_options=options)

You can also pass a mapping object.

.. code-block:: python

    from google.cloud.vision_v1 import ImageAnnotatorClient

    client = ImageAnnotatorClient(
        client_options={
            "api_endpoint": "foo.googleapis.com",
            "client_cert_source" : get_client_cert
        })


"""

from typing import Callable, Mapping, Optional, Sequence, Tuple


class ClientOptions(object):
    """Client Options used to set options on clients.

    Args:
        api_endpoint (Optional[str]): The desired API endpoint, e.g.,
            compute.googleapis.com
        client_cert_source (Optional[Callable[[], Tuple[bytes, bytes]]]): A callback
            which returns client certificate bytes and private key bytes both in
            PEM format. ``client_cert_source`` and ``client_encrypted_cert_source``
            are mutually exclusive.
        client_encrypted_cert_source (Optional[Callable[[], Tuple[str, str, bytes]]]):
            A callback which returns client certificate file path, encrypted
            private key file path, and the passphrase bytes.``client_cert_source``
            and ``client_encrypted_cert_source`` are mutually exclusive.
        quota_project_id (Optional[str]): A project name that a client's
            quota belongs to.
        credentials_file (Optional[str]): A path to a file storing credentials.
            ``credentials_file` and ``api_key`` are mutually exclusive.
        scopes (Optional[Sequence[str]]): OAuth access token override scopes.
        api_key (Optional[str]): Google API key. ``credentials_file`` and
            ``api_key`` are mutually exclusive.
        api_audience (Optional[str]): The intended audience for the API calls
            to the service that will be set when using certain 3rd party
            authentication flows. Audience is typically a resource identifier.
            If not set, the service endpoint value will be used as a default.
            An example of a valid ``api_audience`` is: "https://language.googleapis.com".
        universe_domain (Optional[str]): The desired universe domain. This must match
            the one in credentials. If not set, the default universe domain is
            `googleapis.com`. If both `api_endpoint` and `universe_domain` are set,
            then `api_endpoint` is used as the service endpoint. If `api_endpoint` is
            not specified, the format will be `{service}.{universe_domain}`.

    Raises:
        ValueError: If both ``client_cert_source`` and ``client_encrypted_cert_source``
            are provided, or both ``credentials_file`` and ``api_key`` are provided.
    """

    def __init__(
        self,
        api_endpoint: Optional[str] = None,
        client_cert_source: Optional[Callable[[], Tuple[bytes, bytes]]] = None,
        client_encrypted_cert_source: Optional[
            Callable[[], Tuple[str, str, bytes]]
        ] = None,
        quota_project_id: Optional[str] = None,
        credentials_file: Optional[str] = None,
        scopes: Optional[Sequence[str]] = None,
        api_key: Optional[str] = None,
        api_audience: Optional[str] = None,
        universe_domain: Optional[str] = None,
    ):
        if client_cert_source and client_encrypted_cert_source:
            raise ValueError(
                "client_cert_source and client_encrypted_cert_source are mutually exclusive"
            )
        if api_key and credentials_file:
            raise ValueError("api_key and credentials_file are mutually exclusive")
        self.api_endpoint = api_endpoint
        self.client_cert_source = client_cert_source
        self.client_encrypted_cert_source = client_encrypted_cert_source
        self.quota_project_id = quota_project_id
        self.credentials_file = credentials_file
        self.scopes = scopes
        self.api_key = api_key
        self.api_audience = api_audience
        self.universe_domain = universe_domain

    def __repr__(self) -> str:
        return "ClientOptions: " + repr(self.__dict__)


def from_dict(options: Mapping[str, object]) -> ClientOptions:
    """Construct a client options object from a mapping object.

    Args:
        options (collections.abc.Mapping): A mapping object with client options.
            See the docstring for ClientOptions for details on valid arguments.
    """

    client_options = ClientOptions()

    for key, value in options.items():
        if hasattr(client_options, key):
            setattr(client_options, key, value)
        else:
            raise ValueError("ClientOptions does not accept an option '" + key + "'")

    return client_options
