class RunLifecycleError(Exception):
    pass


class RunLifecycleManager:
    ARMABLE = {"STOPPED", "PAUSED_AUTH_EXPIRED"}

    @classmethod
    def assert_can_arm(cls, status: str):
        normalized = (status or "").strip().upper()
        if normalized == "RUNNING":
            raise RunLifecycleError("Run already RUNNING")
        if normalized == "ERROR":
            raise RunLifecycleError("Run in ERROR must be reset before arming")
        if normalized not in cls.ARMABLE:
            raise RunLifecycleError(f"Run cannot be armed from status {normalized}")
        return normalized

    @classmethod
    def is_armable(cls, status: str) -> bool:
        normalized = (status or "").strip().upper()
        return normalized in cls.ARMABLE