"""Qlib DataHandler for GP-mined factors (loaded from exported pickle)."""

from __future__ import annotations

import pickle
from pathlib import Path

from qlib.data.dataset.handler import DataHandlerLP


class GPFactorHandler(DataHandlerLP):
    """
    Load a pre-built GP factor handler from pickle.
    Used by qrun workflow YAML via module_path.
    """

    def __init__(
        self,
        handler_path: str,
        instruments="csi300",
        start_time=None,
        end_time=None,
        fit_start_time=None,
        fit_end_time=None,
        **kwargs,
    ):
        path = Path(handler_path)
        if not path.is_absolute():
            from config.settings import PROJECT_ROOT

            path = PROJECT_ROOT / path

        if not path.exists():
            raise FileNotFoundError(
                f"GP handler pickle not found: {path}. "
                "Run: python scripts/build_gp_dataset.py --run-id <RUN_ID>"
            )

        with path.open("rb") as f:
            loaded: DataHandlerLP = pickle.load(f)

        self.__dict__.update(loaded.__dict__)
        if start_time is not None:
            self.start_time = start_time
        if end_time is not None:
            self.end_time = end_time
        if fit_start_time is not None:
            self.fit_start_time = fit_start_time
        if fit_end_time is not None:
            self.fit_end_time = fit_end_time
        if instruments is not None:
            self.instruments = instruments