import inspect
import logging
import time
from abc import ABC, abstractmethod
from typing import TYPE_CHECKING, TypeVar

from langgraph.errors import GraphInterrupt
from pydantic import ValidationError

if TYPE_CHECKING:
    from app.config import Settings
from app.exceptions import AppError, ImportProcessError

T = TypeVar("T")


class BaseNode(ABC):
    name: str = "base_node"

    def __init__(self, config: "Settings | None" = None):
        """保存显式配置；全局配置在节点实际使用时才加载。"""
        self._config = config
        self.logger = logging.getLogger(f"import.{self.name}")

    @property
    def config(self) -> "Settings":
        if self._config is None:
            from app.config import settings

            self._config = settings
        return self._config

    def __call__(self, state: T) -> T:
        """执行节点，统一记录日志、耗时并保留业务异常类型"""
        if inspect.iscoroutinefunction(self.process):
            return self._acall(state)
        start_time = time.perf_counter()
        self.logger.info("--- %s 开始 ---", self.name)
        try:
            result = self.process(state)
        except GraphInterrupt:
            raise
        except (AppError, ValidationError):
            self.logger.exception("%s 执行失败", self.name)
            raise
        except Exception as e:
            self.logger.exception("%s 执行失败", self.name)
            raise ImportProcessError(str(e), node_name=self.name) from e
        else:
            self.logger.info("--- %s 完成 ---", self.name)
            return result
        finally:
            self.logger.info(
                "%s 耗时 %.3f 秒", self.name, time.perf_counter() - start_time
            )

    @abstractmethod
    def process(self, state: T) -> T:
        """子类实现节点核心逻辑，返回状态更新"""

    async def _acall(self, state: T) -> T:
        """异步节点等待执行完成后再记录结果和耗时"""
        start_time = time.perf_counter()
        self.logger.info("--- %s 开始 ---", self.name)
        try:
            result = await self.process(state)
        except GraphInterrupt:
            raise
        except (AppError, ValidationError):
            self.logger.exception("%s 执行失败", self.name)
            raise
        except Exception as error:
            self.logger.exception("%s 执行失败", self.name)
            raise ImportProcessError(str(error), node_name=self.name) from error
        else:
            self.logger.info("--- %s 完成 ---", self.name)
            return result
        finally:
            self.logger.info(
                "%s 耗时 %.3f 秒", self.name, time.perf_counter() - start_time
            )

    def log_step(self, step_name: str, message: str = ""):
        """记录步骤日志。"""
        log_msg = f"[{step_name}]"
        if message:
            log_msg += f" {message}"
        self.logger.info(log_msg)