Add metadata handling. (#74)

* Add metadata handling.

* Add and fix tests.

* Resolve comments

Author: MarkDaoust

google/generativeai/client.py

@@ -15,7 +15,10 @@
 from __future__ import annotations
 
 import os
-from typing import cast, Optional, Union
+import dataclasses
+import types
+from typing import Any, cast
+from collections.abc import Sequence
 
 import google.ai.generativelanguage as glm
 
@@ -26,15 +29,163 @@
 
 from google.generativeai import version
 
-
 USER_AGENT = "genai-py"
 
-default_client_config = {}
-default_discuss_client = None
-default_discuss_async_client = None
-default_model_client = None
-default_text_client = None
-default_operations_client = None
+
+@dataclasses.dataclass
+class _ClientManager:
+    client_config: dict[str, Any] = dataclasses.field(default_factory=dict)
+    default_metadata: Sequence[tuple[str, str]] = ()
+    discuss_client: glm.DiscussServiceClient | None = None
+    discuss_async_client: glm.DiscussServiceAsyncClient | None = None
+    model_client: glm.ModelServiceClient | None = None
+    text_client: glm.TextServiceClient | None = None
+    operations_client = None
+
+    def configure(
+        self,
+        *,
+        api_key: str | None = None,
+        credentials: ga_credentials.Credentials | dict | None = None,
+        # The user can pass a string to choose `rest` or `grpc` or 'grpc_asyncio'.
+        # See `_transport_registry` in `DiscussServiceClientMeta`.
+        # Since the transport classes align with the client classes it wouldn't make
+        # sense to accept a `Transport` object here even though the client classes can.
+        # We could accept a dict since all the `Transport` classes take the same args,
+        # but that seems rare. Users that need it can just switch to the low level API.
+        transport: str | None = None,
+        client_options: client_options_lib.ClientOptions | dict | None = None,
+        client_info: gapic_v1.client_info.ClientInfo | None = None,
+        default_metadata: Sequence[tuple[str, str]] = (),
+    ) -> None:
+        """Captures default client configuration.
+
+        If no API key has been provided (either directly, or on `client_options`) and the
+        `GOOGLE_API_KEY` environment variable is set, it will be used as the API key.
+
+        Note: Not all arguments are detailed below. Refer to the `*ServiceClient` classes in
+        `google.ai.generativelanguage` for details on the other arguments.
+
+        Args:
+            transport: A string, one of: [`rest`, `grpc`, `grpc_asyncio`].
+            api_key: The API-Key to use when creating the default clients (each service uses
+                a separate client). This is a shortcut for `client_options={"api_key": api_key}`.
+                If omitted, and the `GOOGLE_API_KEY` environment variable is set, it will be
+                used.
+            default_metadata: Default (key, value) metadata pairs to send with every request.
+                when using `transport="rest"` these are sent as HTTP headers.
+        """
+        if isinstance(client_options, dict):
+            client_options = client_options_lib.from_dict(client_options)
+        if client_options is None:
+            client_options = client_options_lib.ClientOptions()
+        client_options = cast(client_options_lib.ClientOptions, client_options)
+        had_api_key_value = getattr(client_options, "api_key", None)
+
+        if had_api_key_value:
+            if api_key is not None:
+                raise ValueError("You can't set both `api_key` and `client_options['api_key']`.")
+        else:
+            if api_key is None:
+                # If no key is provided explicitly, attempt to load one from the
+                # environment.
+                api_key = os.getenv("GOOGLE_API_KEY")
+
+            client_options.api_key = api_key
+
+        user_agent = f"{USER_AGENT}/{version.__version__}"
+        if client_info:
+            # Be respectful of any existing agent setting.
+            if client_info.user_agent:
+                client_info.user_agent += f" {user_agent}"
+            else:
+                client_info.user_agent = user_agent
+        else:
+            client_info = gapic_v1.client_info.ClientInfo(user_agent=user_agent)
+
+        client_config = {
+            "credentials": credentials,
+            "transport": transport,
+            "client_options": client_options,
+            "client_info": client_info,
+        }
+
+        client_config = {key: value for key, value in client_config.items() if value is not None}
+
+        self.client_config = client_config
+        self.default_metadata = default_metadata
+        self.discuss_client = None
+        self.text_client = None
+        self.model_client = None
+        self.operations_client = None
+
+    def make_client(self, cls):
+        # Attempt to configure using defaults.
+        if not self.client_config:
+            configure()
+
+        client = cls(**self.client_config)
+
+        if not self.default_metadata:
+            return client
+
+        def keep(name, f):
+            if name.startswith("_"):
+                return False
+            elif not isinstance(f, types.FunctionType):
+                return False
+            elif isinstance(f, classmethod):
+                return False
+            elif isinstance(f, staticmethod):
+                return False
+            else:
+                return True
+
+        def add_default_metadata_wrapper(f):
+            def call(*args, metadata=(), **kwargs):
+                metadata = list(metadata) + list(self.default_metadata)
+                return f(*args, **kwargs, metadata=metadata)
+
+            return call
+
+        for name, value in cls.__dict__.items():
+            if not keep(name, value):
+                continue
+            f = getattr(client, name)
+            f = add_default_metadata_wrapper(f)
+            setattr(client, name, f)
+
+        return client
+
+    def get_default_discuss_client(self) -> glm.DiscussServiceClient:
+        if self.discuss_client is None:
+            self.discuss_client = self.make_client(glm.DiscussServiceClient)
+        return self.discuss_client
+
+    def get_default_text_client(self) -> glm.TextServiceClient:
+        if self.text_client is None:
+            self.text_client = self.make_client(glm.TextServiceClient)
+        return self.text_client
+
+    def get_default_discuss_async_client(self) -> glm.DiscussServiceAsyncClient:
+        if self.discuss_async_client is None:
+            self.discuss_async_client = self.make_client(glm.DiscussServiceAsyncClient)
+        return self.discuss_async_client
+
+    def get_default_model_client(self) -> glm.ModelServiceClient:
+        if self.model_client is None:
+            self.model_client = self.make_client(glm.ModelServiceClient)
+        return self.model_client
+
+    def get_default_operations_client(self) -> operations_v1.OperationsClient:
+        if self.operations_client is None:
+            self.model_client = get_default_model_client()
+            self.operations_client = self.model_client._transport.operations_client
+
+        return self.operations_client
+
+
+_client_manager = _ClientManager()
 
 
 def configure(
@@ -50,119 +201,50 @@ def configure(
     transport: str | None = None,
     client_options: client_options_lib.ClientOptions | dict | None = None,
     client_info: gapic_v1.client_info.ClientInfo | None = None,
+    default_metadata: Sequence[tuple[str, str]] = (),
 ):
     """Captures default client configuration.
 
     If no API key has been provided (either directly, or on `client_options`) and the
     `GOOGLE_API_KEY` environment variable is set, it will be used as the API key.
 
+    Note: Not all arguments are detailed below. Refer to the `*ServiceClient` classes in
+    `google.ai.generativelanguage` for details on the other arguments.
+
     Args:
-        Refer to `glm.DiscussServiceClient`, and `glm.ModelsServiceClient` for details on additional arguments.
+        transport: A string, one of: [`rest`, `grpc`, `grpc_asyncio`].
         api_key: The API-Key to use when creating the default clients (each service uses
             a separate client). This is a shortcut for `client_options={"api_key": api_key}`.
             If omitted, and the `GOOGLE_API_KEY` environment variable is set, it will be
             used.
+        default_metadata: Default (key, value) metadata pairs to send with every request.
+            when using `transport="rest"` these are sent as HTTP headers.
     """
-    global default_client_config
-    global default_discuss_client
-    global default_model_client
-    global default_text_client
-    global default_operations_client
-
-    if isinstance(client_options, dict):
-        client_options = client_options_lib.from_dict(client_options)
-    if client_options is None:
-        client_options = client_options_lib.ClientOptions()
-    client_options = cast(client_options_lib.ClientOptions, client_options)
-    had_api_key_value = getattr(client_options, "api_key", None)
-
-    if had_api_key_value:
-        if api_key is not None:
-            raise ValueError("You can't set both `api_key` and `client_options['api_key']`.")
-    else:
-        if api_key is None:
-            # If no key is provided explicitly, attempt to load one from the
-            # environment.
-            api_key = os.getenv("GOOGLE_API_KEY")
-
-        client_options.api_key = api_key
-
-    user_agent = f"{USER_AGENT}/{version.__version__}"
-    if client_info:
-        # Be respectful of any existing agent setting.
-        if client_info.user_agent:
-            client_info.user_agent += f" {user_agent}"
-        else:
-            client_info.user_agent = user_agent
-    else:
-        client_info = gapic_v1.client_info.ClientInfo(user_agent=user_agent)
-
-    new_default_client_config = {
-        "credentials": credentials,
-        "transport": transport,
-        "client_options": client_options,
-        "client_info": client_info,
-    }
-
-    new_default_client_config = {
-        key: value for key, value in new_default_client_config.items() if value is not None
-    }
-
-    default_client_config = new_default_client_config
-    default_discuss_client = None
-    default_text_client = None
-    default_model_client = None
-    default_operations_client = None
+    return _client_manager.configure(
+        api_key=api_key,
+        credentials=credentials,
+        transport=transport,
+        client_options=client_options,
+        client_info=client_info,
+        default_metadata=default_metadata,
+    )
 
 
 def get_default_discuss_client() -> glm.DiscussServiceClient:
-    global default_discuss_client
-    if default_discuss_client is None:
-        # Attempt to configure using defaults.
-        if not default_client_config:
-            configure()
-        default_discuss_client = glm.DiscussServiceClient(**default_client_config)
-
-    return default_discuss_client
+    return _client_manager.get_default_discuss_client()
 
 
 def get_default_text_client() -> glm.TextServiceClient:
-    global default_text_client
-    if default_text_client is None:
-        # Attempt to configure using defaults.
-        if not default_client_config:
-            configure()
-        default_text_client = glm.TextServiceClient(**default_client_config)
-
-    return default_text_client
+    return _client_manager.get_default_text_client()
 
 
-def get_default_discuss_async_client() -> glm.DiscussServiceAsyncClient:
-    global default_discuss_async_client
-    if default_discuss_async_client is None:
-        # Attempt to configure using defaults.
-        if not default_client_config:
-            configure()
-        default_discuss_async_client = glm.DiscussServiceAsyncClient(**default_client_config)
-
-    return default_discuss_async_client
-
-
-def get_default_model_client() -> glm.ModelServiceClient:
-    global default_model_client
-    if default_model_client is None:
-        # Attempt to configure using defaults.
-        if not default_client_config:
-            configure()
-        default_model_client = glm.ModelServiceClient(**default_client_config)
+def get_default_operations_client() -> operations_v1.OperationsClient:
+    return _client_manager.get_default_operations_client()
 
-    return default_model_client
 
+def get_default_discuss_async_client() -> glm.DiscussServiceAsyncClient:
+    return _client_manager.get_default_discuss_async_client()
 
-def get_default_operations_client() -> operations_v1.OperationsClient:
-    global default_operations_client
-    if default_operations_client is None:
-        model_client = get_default_model_client()
-        default_operations_client = model_client._transport.operations_client
 
-    return default_operations_client
+def get_default_model_client() -> glm.ModelServiceAsyncClient:
+    return _client_manager.get_default_model_client()