import { DeviceRotation } from '@monkvision/types';
/**
 * Duration (in ms) of the rolling window used to measure the compass's sustained rotation speed.
 */
export declare const WALKING_DETECTION_WINDOW_MS = 700;
/**
 * Minimum time span (in ms) that must be covered by the rolling window before a rotation speed measurement is
 * considered reliable. This avoids computing a noisy velocity over a too short (e.g. single-frame) time span.
 */
export declare const WALKING_DETECTION_MIN_WINDOW_MS = 350;
/**
 * Sustained compass rotation speed (in degrees per second) above which the user is considered to be walking too
 * fast around the vehicle.
 *
 * Derived from the target walkaround duration of ~50 seconds for a full 360° turn (an average speed of
 * ~9 deg/sec), with a safety margin applied on top of that average.
 */
export declare const WALKING_VELOCITY_THRESHOLD_DEG_PER_SEC = 24;
/**
 * Enumeration of the different fast movements that can be detected.
 */
export declare enum FastMovementType {
    /**
     * The user is walking too fast around the vehicle.
     */
    WALKING_TOO_FAST = "walking_too_fast",
    /**
     * The user is shaking their phone too much.
     */
    PHONE_SHAKING = "phone_shaking"
}
/**
 * A single timestamped alpha (compass heading) sample, used to measure the sustained rotation speed of the device
 * over a rolling window.
 */
export interface AlphaSample {
    /**
     * The compass heading, in degrees.
     */
    alpha: number;
    /**
     * The timestamp (in ms, as returned by Date.now()) at which this sample was recorded.
     */
    timestamp: number;
}
/**
 * Returns a new alpha history array with every sample older than WALKING_DETECTION_WINDOW_MS (relative to the given
 * timestamp) removed.
 */
export declare function pruneAlphaHistory(history: AlphaSample[], timestamp: number): AlphaSample[];
/**
 * Function used to detect fast user movements based on device rotation data.
 *
 * Phone shaking is detected from the instantaneous beta/gamma delta between two consecutive readings.
 * Walking too fast is detected from the sustained alpha rotation speed measured over a rolling window.
 */
export declare function detectFastMovements(rotation: DeviceRotation, previousRotation: DeviceRotation, alphaHistory: AlphaSample[]): FastMovementType | null;