from abc import ABC, abstractmethod
from pathlib import Path
from typing import Any


class BaseEngine(ABC):
    """模型类型专用训练引擎的抽象接口。"""

    @abstractmethod
    async def load_model(self, model_id: str, **kwargs: Any) -> None:
        """Download and load the base model."""
        ...

    @abstractmethod
    def get_peft_config(self, method: str, params: dict[str, Any]) -> Any:
        """Build and return a PEFT config object for the given method."""
        ...

    @abstractmethod
    async def preprocess_dataset(
        self, dataset_path: str, output_path: str, **kwargs: Any
    ) -> str:
        """将原始数据集预处理为训练格式。返回处理后路径。"""
        ...

    @abstractmethod
    async def train(
        self,
        job_id: str,
        dataset_path: str,
        peft_config: Any,
        training_args: dict[str, Any],
    ) -> str:
        """执行训练循环。返回保存的 adapter 路径。"""
        ...

    @abstractmethod
    def get_model_info(self, model_id: str) -> dict[str, Any]:
        """返回模型元数据（类型、上下文长度、支持的 PEFT 方法等）。"""
        ...