from __future__ import annotations


class ApexAgentError(Exception):
    """Base error for semantic errors surfaced above the driver layer."""


class DriverError(ApexAgentError):
    """A driver operation failed."""


class DeviceNotFoundError(ApexAgentError):
    """A requested device id is unknown."""


class DeviceOfflineError(ApexAgentError):
    """A device is unavailable or lost its connection."""


class DeviceBusyError(ApexAgentError):
    """A device is already in use."""


class ElementNotFoundError(ApexAgentError):
    """A requested screen element was not found."""


class TaskFailedError(ApexAgentError):
    """A task failed before reaching its goal."""