class AppError(Exception):
    """应用业务异常。"""


class ImportProcessError(AppError):
    """导入流程异常，保留节点名称和原始异常信息"""

    def __init__(
        self, message: str, node_name: str = "", cause: Exception | None = None
    ):
        self.node_name = node_name
        self.cause = cause
        super().__init__(message)

    def __str__(self) -> str:
        parts = []
        if self.node_name:
            parts.append(f"[{self.node_name}]")
        parts.append(super().__str__())
        if self.cause is not None:
            parts.append(f"(原因: {self.cause})")
        return " ".join(parts)