from __future__ import annotations
import inspect
from typing import Any, Awaitable, Callable, List, Mapping, Protocol, Sequence, TypeVar, get_type_hints
from ._agent_id import AgentId
from ._agent_instantiation import AgentInstantiationContext
from ._agent_metadata import AgentMetadata
from ._agent_runtime import AgentRuntime
from ._agent_type import AgentType
from ._base_agent import BaseAgent
from ._cancellation_token import CancellationToken
from ._message_context import MessageContext
from ._serialization import try_get_known_serializers_for_type
from ._subscription import Subscription
from ._subscription_context import SubscriptionInstantiationContext
from ._topic import TopicId
from ._type_helpers import get_types
from .exceptions import CantHandleException
T = TypeVar("T")
ClosureAgentType = TypeVar("ClosureAgentType", bound="ClosureAgent")
def get_handled_types_from_closure(
closure: Callable[[ClosureAgent, T, MessageContext], Awaitable[Any]],
) -> Sequence[type]:
args = inspect.getfullargspec(closure)[0]
if len(args) != 3:
raise AssertionError("Closure must have 4 arguments")
message_arg_name = args[1]
type_hints = get_type_hints(closure)
if "return" not in type_hints:
raise AssertionError("return not found in function signature")
# Get the type of the message parameter
target_types = get_types(type_hints[message_arg_name])
if target_types is None:
raise AssertionError("Message type not found")
# print(type_hints)
return_types = get_types(type_hints["return"])
if return_types is None:
raise AssertionError("Return type not found")
return target_types
[docs]
class ClosureContext(Protocol):
@property
def id(self) -> AgentId: ...
[docs]
async def send_message(
self,
message: Any,
recipient: AgentId,
*,
cancellation_token: CancellationToken | None = None,
) -> Any: ...
[docs]
async def publish_message(
self,
message: Any,
topic_id: TopicId,
*,
cancellation_token: CancellationToken | None = None,
) -> None: ...
[docs]
class ClosureAgent(BaseAgent, ClosureContext):
def __init__(
self, description: str, closure: Callable[[ClosureContext, T, MessageContext], Awaitable[Any]]
) -> None:
try:
runtime = AgentInstantiationContext.current_runtime()
id = AgentInstantiationContext.current_agent_id()
except Exception as e:
raise RuntimeError(
"ClosureAgent must be instantiated within the context of an AgentRuntime. It cannot be directly instantiated."
) from e
self._runtime: AgentRuntime = runtime
self._id: AgentId = id
self._description = description
handled_types = get_handled_types_from_closure(closure)
self._expected_types = handled_types
self._closure = closure
super().__init__(description)
@property
def metadata(self) -> AgentMetadata:
assert self._id is not None
return AgentMetadata(
key=self._id.key,
type=self._id.type,
description=self._description,
)
@property
def id(self) -> AgentId:
return self._id
@property
def runtime(self) -> AgentRuntime:
return self._runtime
[docs]
async def on_message_impl(self, message: Any, ctx: MessageContext) -> Any:
if type(message) not in self._expected_types:
raise CantHandleException(
f"Message type {type(message)} not in target types {self._expected_types} of {self.id}"
)
return await self._closure(self, message, ctx)
[docs]
async def save_state(self) -> Mapping[str, Any]:
"""Closure agents do not have state. So this method always returns an empty dictionary."""
return {}
[docs]
async def load_state(self, state: Mapping[str, Any]) -> None:
"""Closure agents do not have state. So this method does nothing."""
pass
[docs]
@classmethod
async def register_closure(
cls,
runtime: AgentRuntime,
type: str,
closure: Callable[[ClosureContext, T, MessageContext], Awaitable[Any]],
*,
skip_class_subscriptions: bool = False,
skip_direct_message_subscription: bool = False,
description: str = "",
subscriptions: Callable[[], list[Subscription] | Awaitable[list[Subscription]]] | None = None,
) -> AgentType:
def factory() -> ClosureAgent:
return ClosureAgent(description=description, closure=closure)
agent_type = await cls.register(
runtime=runtime,
type=type,
factory=factory, # type: ignore
skip_class_subscriptions=skip_class_subscriptions,
skip_direct_message_subscription=skip_direct_message_subscription,
)
subscriptions_list: List[Subscription] = []
if subscriptions is not None:
with SubscriptionInstantiationContext.populate_context(agent_type):
subscriptions_list_result = subscriptions()
if inspect.isawaitable(subscriptions_list_result):
subscriptions_list.extend(await subscriptions_list_result)
else:
# just ignore mypy here
subscriptions_list.extend(subscriptions_list_result) # type: ignore
for subscription in subscriptions_list:
await runtime.add_subscription(subscription)
handled_types = get_handled_types_from_closure(closure)
for message_type in handled_types:
# TODO: support custom serializers
serializer = try_get_known_serializers_for_type(message_type)
runtime.add_message_serializer(serializer)
return agent_type
