main.py

import asyncio
import logging
import os
import uuid  # for generating thread IDs for checkpointer
from typing import AsyncIterator, Optional, TypedDict

from dotenv import find_dotenv, load_dotenv
from langgraph.checkpoint.memory import MemorySaver
from langgraph.graph import END, START, StateGraph
from smolagents import CodeAgent, LiteLLMModel
from smolagents.memory import ActionStep, FinalAnswerStep
from smolagents.monitoring import LogLevel

# Configure logging
logging.basicConfig(
    level=logging.INFO, format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
)
logger = logging.getLogger(__name__)

# Load environment variables
load_dotenv(find_dotenv())

# Get required environment variables with validation
API_BASE = os.getenv("API_BASE")
API_KEY = os.getenv("API_KEY")
MODEL_ID = os.getenv("MODEL_ID")

if not all([API_BASE, API_KEY, MODEL_ID]):
    raise ValueError(
        "Missing required environment variables: API_BASE, API_KEY, MODEL_ID"
    )


# Define the state types for our graph
class AgentState(TypedDict):
    task: str
    current_step: Optional[dict]  # Store serializable dict instead of ActionStep
    error: Optional[str]
    answer_text: Optional[str]


# Initialize model with error handling
try:
    model = LiteLLMModel(
        api_base=API_BASE,
        api_key=API_KEY,
        model_id=MODEL_ID,
    )
except Exception as e:
    logger.error(f"Failed to initialize model: {str(e)}")
    raise

# Initialize agent with error handling
try:
    agent = CodeAgent(
        add_base_tools=True,
        additional_authorized_imports=["pandas", "numpy"],
        max_steps=10,
        model=model,
        tools=[],
        step_callbacks=None,
        verbosity_level=LogLevel.ERROR,
    )
    agent.logger.console.width = 66
except Exception as e:
    logger.error(f"Failed to initialize agent: {str(e)}")
    raise


async def process_step(state: AgentState) -> AgentState:
    """Process a single step of the agent's execution."""
    try:
        # Clear previous step results before running agent.run
        state["current_step"] = None
        state["answer_text"] = None
        state["error"] = None

        steps = agent.run(
            task=state["task"],
            additional_args=None,
            images=None,
            max_steps=1,  # Process one step at a time
            stream=True,
            reset=False,  # Maintain agent's internal state across process_step calls
        )

        for step in steps:
            if isinstance(step, ActionStep):
                # Convert ActionStep to serializable dict using the correct attributes
                state["current_step"] = {
                    "step_number": step.step_number,
                    "model_output": step.model_output,
                    "observations": step.observations,
                    "tool_calls": [
                        {"name": tc.name, "arguments": tc.arguments}
                        for tc in (step.tool_calls or [])
                    ],
                    "action_output": step.action_output,
                }
                logger.info(f"Processed action step {step.step_number}")
            elif isinstance(step, FinalAnswerStep):
                state["answer_text"] = step.final_answer
                logger.info("Processed final answer")
                logger.debug(f"Final answer details: {step}")
                logger.info(f"Extracted answer text: {state['answer_text']}")
                # Return immediately when we get a final answer
                return state
        # If loop finishes without FinalAnswerStep, return current state
        return state
    except Exception as e:
        state["error"] = str(e)
        logger.error(f"Error during agent execution step: {str(e)}")
        return state


def should_continue(state: AgentState) -> bool:
    """Determine if the agent should continue processing steps."""
    # Continue if we don't have an answer_text and no error
    continue_execution = state.get("answer_text") is None and state.get("error") is None
    logger.debug(
        f"Checking should_continue: answer_text={state.get('answer_text') is not None}, error={state.get('error') is not None} -> Continue={continue_execution}"
    )
    return continue_execution


# Build the LangGraph graph once with persistence
memory = MemorySaver()
builder = StateGraph(AgentState)
builder.add_node("process_step", process_step)
builder.add_edge(START, "process_step")
builder.add_conditional_edges(
    "process_step", should_continue, {True: "process_step", False: END}
)
graph = builder.compile(checkpointer=memory)


async def stream_execution(task: str, thread_id: str) -> AsyncIterator[AgentState]:
    """Stream the execution of the agent."""
    if not task:
        raise ValueError("Task cannot be empty")

    logger.info(f"Initializing agent execution for task: {task}")

    # Initialize the state
    initial_state: AgentState = {
        "task": task,
        "current_step": None,
        "error": None,
        "answer_text": None,
    }

    # Pass thread_id via the config dict so the checkpointer can persist state
    async for state in graph.astream(
        initial_state, {"configurable": {"thread_id": thread_id}}
    ):
        yield state
        # Propagate error immediately if it occurs without an answer
        if state.get("error") and not state.get("answer_text"):
            logger.error(f"Propagating error from stream: {state['error']}")
            raise Exception(state["error"])


async def run_with_streaming(task: str, thread_id: str) -> dict:
    """Run the agent with streaming output and return the results."""
    last_state = None
    steps = []
    error = None
    final_answer_text = None

    try:
        logger.info(f"Starting execution run for task: {task}")
        async for state in stream_execution(task, thread_id):
            last_state = state

            if current_step := state.get("current_step"):
                if not steps or steps[-1]["step_number"] != current_step["step_number"]:
                    steps.append(current_step)
                    # Keep print here for direct user feedback during streaming
                    print(f"\nStep {current_step['step_number']}:")
                    print(f"Model Output: {current_step['model_output']}")
                    print(f"Observations: {current_step['observations']}")
                    if current_step.get("tool_calls"):
                        print("Tool Calls:")
                        for tc in current_step["tool_calls"]:
                            print(f"  - {tc['name']}: {tc['arguments']}")
                    if current_step.get("action_output"):
                        print(f"Action Output: {current_step['action_output']}")

        # After the stream is finished, process the last state
        logger.info("Stream finished.")
        if last_state:
            # LangGraph streams dicts where keys are node names, values are state dicts
            node_name = list(last_state.keys())[0]
            actual_state = last_state.get(node_name)
            if actual_state:
                final_answer_text = actual_state.get("answer_text")
                error = actual_state.get("error")
                logger.info(
                    f"Final answer text extracted from last state: {final_answer_text}"
                )
                logger.info(f"Error extracted from last state: {error}")
                # Ensure steps list is consistent with the final state if needed
                last_step_in_state = actual_state.get("current_step")
                if last_step_in_state and (
                    not steps
                    or steps[-1]["step_number"] != last_step_in_state["step_number"]
                ):
                    logger.debug("Adding last step from final state to steps list.")
                    steps.append(last_step_in_state)
            else:
                logger.warning(
                    "Could not find actual state dictionary within last_state."
                )

        return {"steps": steps, "final_answer": final_answer_text, "error": error}

    except Exception as e:
        import traceback

        logger.error(
            f"Exception during run_with_streaming: {str(e)}\n{traceback.format_exc()}"
        )
        # Attempt to return based on the last known state even if exception occurred outside stream
        final_answer_text = None
        error_msg = str(e)
        if last_state:
            node_name = list(last_state.keys())[0]
            actual_state = last_state.get(node_name)
            if actual_state:
                final_answer_text = actual_state.get("answer_text")

        return {"steps": steps, "final_answer": final_answer_text, "error": error_msg}


def main(task: str, thread_id: str = str(uuid.uuid4())):
    logger.info(
        f"Starting agent run from __main__ for task: '{task}' with thread_id: {thread_id}"
    )
    result = asyncio.run(run_with_streaming(task, thread_id))
    logger.info("Agent run finished.")

    # Print final results
    print("\n--- Execution Results ---")
    print(f"Number of Steps: {len(result.get('steps', []))}")
    # Optionally print step details
    # for i, step in enumerate(result.get('steps', [])):
    #    print(f"Step {i+1} Details: {step}")
    print(f"Final Answer: {result.get('final_answer') or 'Not found'}")
    if err := result.get("error"):
        print(f"Error: {err}")

    return result.get("final_answer")


if __name__ == "__main__":
    # Example Usage
    task_to_run = "What is the capital of France?"
    thread_id = str(uuid.uuid4())  # Generate a unique thread ID for this run

    final_answer = main(task_to_run, thread_id)
    print(f"Final Answer: {final_answer}")