"""Application-specific exception hierarchy."""


class ApplicationError(Exception):
    """Base class for expected application errors."""


class ConfigurationError(ApplicationError):
    """Raised when configuration is missing or invalid."""


class CameraOpenError(ApplicationError):
    """Raised when an input source cannot be opened."""


class FrameReadError(ApplicationError):
    """Raised after repeated camera frame read failures."""


class ModelLoadError(ApplicationError):
    """Raised when the YOLO model cannot be loaded."""


class VideoWriterError(ApplicationError):
    """Raised when an output video writer cannot be opened."""


class TrackerError(ApplicationError):
    """Raised when the external tracker cannot be initialized or updated."""


class TrackManagementError(ApplicationError):
    """Raised when accumulated track state is inconsistent."""


class TrackingLogError(ApplicationError):
    """Raised when tracking CSV files cannot be written."""


class FaceProcessingError(ApplicationError):
    """Raised when the face backend cannot be initialized."""


class FaceLogError(ApplicationError):
    """Raised when face CSV logs cannot be opened or written."""


class TurnLogError(ApplicationError):
    """Raised when turn-analysis CSV files cannot be opened or written."""


class VoiceLogError(ApplicationError):
    """Raised when voice-prompt CSV files cannot be opened or written."""


class PersonStateLogError(ApplicationError):
    """Raised when integrated person-state CSV files cannot be written."""


class UnifiedLogError(ApplicationError):
    """Raised when Phase 7 unified CSV files cannot be written."""