pocketflow/cookbook/pocketflow_a2a/task_manager.py

# FILE: pocketflow_a2a_agent/task_manager.py
import logging
from typing import AsyncIterable, Union
import asyncio

# Import from the common code you copied
from common.server.task_manager import InMemoryTaskManager
from common.types import (
    JSONRPCResponse, SendTaskRequest, SendTaskResponse,
    SendTaskStreamingRequest, SendTaskStreamingResponse, Task, TaskSendParams,
    TaskState, TaskStatus, TextPart, Artifact, UnsupportedOperationError,
    InternalError, InvalidParamsError
)
import common.server.utils as server_utils

# Import directly from your original PocketFlow files
from .flow import create_agent_flow # Assumes flow.py is in the same directory
from .utils import call_llm, search_web # Make utils functions available if needed elsewhere

logger = logging.getLogger(__name__)

class PocketFlowTaskManager(InMemoryTaskManager):
    """ TaskManager implementation that runs the PocketFlow agent. """

    SUPPORTED_CONTENT_TYPES = ["text", "text/plain"] # Define what the agent accepts/outputs

    async def on_send_task(self, request: SendTaskRequest) -> SendTaskResponse:
        """Handles non-streaming task requests."""
        logger.info(f"Received task send request: {request.params.id}")

        # Validate output modes
        if not server_utils.are_modalities_compatible(
            request.params.acceptedOutputModes, self.SUPPORTED_CONTENT_TYPES
        ):
            logger.warning(
                "Unsupported output mode. Received %s, Support %s",
                request.params.acceptedOutputModes, self.SUPPORTED_CONTENT_TYPES
            )
            return SendTaskResponse(id=request.id, error=server_utils.new_incompatible_types_error(request.id).error)

        # Upsert the task in the store (initial state: submitted)
        # We create the task first so its state can be tracked, even if the sync execution fails
        await self.upsert_task(request.params)
        # Update state to working before running
        await self.update_store(request.params.id, TaskStatus(state=TaskState.WORKING), [])


        # --- Run the PocketFlow logic ---
        task_params: TaskSendParams = request.params
        query = self._get_user_query(task_params)
        if query is None:
            fail_status = TaskStatus(state=TaskState.FAILED, message=Message(role="agent", parts=[TextPart(text="No text query found")]))
            await self.update_store(task_params.id, fail_status, [])
            return SendTaskResponse(id=request.id, error=InvalidParamsError(message="No text query found in message parts"))

        shared_data = {"question": query}
        agent_flow = create_agent_flow() # Create the flow instance

        try:
            # Run the synchronous PocketFlow
            # In a real async server, you might run this in a separate thread/process
            # executor to avoid blocking the event loop. For simplicity here, we run it directly.
            # Consider adding a timeout if flows can hang.
            logger.info(f"Running PocketFlow for task {task_params.id}...")
            final_state_dict = agent_flow.run(shared_data)
            logger.info(f"PocketFlow completed for task {task_params.id}")
            answer_text = final_state_dict.get("answer", "Agent did not produce a final answer text.")

            # --- Package result into A2A Task ---
            final_task_status = TaskStatus(state=TaskState.COMPLETED)
            # Package the answer as an artifact
            final_artifact = Artifact(parts=[TextPart(text=answer_text)])

            # Update the task in the store with final status and artifact
            final_task = await self.update_store(
                task_params.id, final_task_status, [final_artifact]
            )

            # Prepare and return the A2A response
            task_result = self.append_task_history(final_task, task_params.historyLength)
            return SendTaskResponse(id=request.id, result=task_result)

        except Exception as e:
            logger.error(f"Error executing PocketFlow for task {task_params.id}: {e}", exc_info=True)
            # Update task state to FAILED
            fail_status = TaskStatus(
                state=TaskState.FAILED,
                message=Message(role="agent", parts=[TextPart(text=f"Agent execution failed: {e}")])
            )
            await self.update_store(task_params.id, fail_status, [])
            return SendTaskResponse(id=request.id, error=InternalError(message=f"Agent error: {e}"))

    async def on_send_task_subscribe(
        self, request: SendTaskStreamingRequest
    ) -> Union[AsyncIterable[SendTaskStreamingResponse], JSONRPCResponse]:
        """Handles streaming requests - Not implemented for this synchronous agent."""
        logger.warning(f"Streaming requested for task {request.params.id}, but not supported by this PocketFlow agent implementation.")
        # Return an error indicating streaming is not supported
        return JSONRPCResponse(id=request.id, error=UnsupportedOperationError(message="Streaming not supported by this agent"))

    def _get_user_query(self, task_send_params: TaskSendParams) -> str | None:
        """Extracts the first text part from the user message."""
        if not task_send_params.message or not task_send_params.message.parts:
            logger.warning(f"No message parts found for task {task_send_params.id}")
            return None
        for part in task_send_params.message.parts:
            # Ensure part is treated as a dictionary if it came from JSON
            part_dict = part if isinstance(part, dict) else part.model_dump()
            if part_dict.get("type") == "text" and "text" in part_dict:
                 return part_dict["text"]
        logger.warning(f"No text part found in message for task {task_send_params.id}")
        return None # No text part found