"""agent.py – GAIA benchmark agent using *smolagents*.

This module exposes:

* ``gaia_agent()`` – factory returning a ready‑to‑use agent instance.
* ``GAIAAgent``  – subclass of ``smolagents.CodeAgent``.

The LLM backend is chosen at runtime via the ``MODEL_PROVIDER``
environment variable (``hf`` or ``openai``) exactly like *example.py*.
"""

import os
from typing import Any, Sequence

from dotenv import load_dotenv

# SmolAgents Tools
from smolagents import (
    CodeAgent,
    DuckDuckGoSearchTool,
    Tool,
)

# Custom Tools from tools.py
from tools import (
    PythonRunTool,
    ExcelLoaderTool,
    YouTubeTranscriptTool,
    AudioTranscriptionTool,
    SimpleOCRTool,
)

# ---------------------------------------------------------------------------
# Model selection helper
# ---------------------------------------------------------------------------

load_dotenv()  # Make sure we read credentials from .env when running locally

def _select_model():
    """Return a smolagents *model* as configured by the ``MODEL_PROVIDER`` env."""

    provider = os.getenv("MODEL_PROVIDER", "hf").lower()

    if provider == "hf":
        from smolagents import InferenceClientModel
        hf_model_id = os.getenv("HF_MODEL", "HuggingFaceH4/zephyr-7b-beta")
        hf_token = os.getenv("HF_API_KEY")
        return InferenceClientModel(model_id=hf_model_id, token=hf_token)

    if provider == "openai":
        from smolagents import OpenAIServerModel
        openai_model_id = os.getenv("OPENAI_MODEL", "gpt-3.5-turbo")
        openai_token = os.getenv("OPENAI_API_KEY")
        return OpenAIServerModel(model_id=openai_model_id, api_key=openai_token)

    raise ValueError(
        f"Unsupported MODEL_PROVIDER: {provider!r}. "
        "Use 'hf' (default) or 'openai'."
    )

# ---------------------------------------------------------------------------
# Core Agent implementation
# ---------------------------------------------------------------------------

DEFAULT_TOOLS = [
    DuckDuckGoSearchTool(),
    PythonRunTool(),
    ExcelLoaderTool(),
    YouTubeTranscriptTool(),
    AudioTranscriptionTool(),
    SimpleOCRTool(),
]

class GAIAAgent(CodeAgent):
    def __init__(self, tools=None):
        super().__init__(tools=tools or DEFAULT_TOOLS, model=_select_model())

    # Convenience so the object itself can be *called* directly
    def __call__(self, question: str, **kwargs: Any) -> str:
        steps = self.run(question, **kwargs)
        last_step = None
        for step in steps:
            last_step = step
        # If last_step is a FinalAnswerStep with .answer, return it
        answer = getattr(last_step, "answer", None)
        if answer is not None:
            return str(answer)
        return str(last_step)

# ---------------------------------------------------------------------------
# Factory helpers expected by app.py
# ---------------------------------------------------------------------------

def gaia_agent(*, extra_tools: Sequence[Tool] | None = None) -> GAIAAgent:
    # Compose the toolset: always include all default tools, plus any extras
    toolset = list(DEFAULT_TOOLS)
    if extra_tools:
        toolset.extend(extra_tools)
    return GAIAAgent(tools=toolset)

__all__ = ["GAIAAgent", "gaia_agent"]