/**
 * Configuration and metadata for an ephemeral actor timer.
 *
 * Timers are non-durable, recurring callbacks that exist only for the lifetime of the
 * current actor activation. Unlike reminders, timers are not persisted and are lost on
 * actor deactivation or failover. Timers are useful for ephemeral state management,
 * cleanup tasks, and timeout-based logic.
 *
 * ActorTimerData encapsulates the complete timer specification. It is created during
 * actor timer registration and managed by the actor runtime. The current implementation
 * supports basic timer scheduling with dueTime and period. Future enhancements may add
 * time-to-live (TTL) and jitter support.
 *
 * @remarks
 * Timers have the following lifecycle:
 * - Registered via {@link AbstractActor#registerActorTimer}
 * - Stored in memory, not persisted to the Dapr state store
 * - Fired at (dueTime) initially, then every (period) interval (if period > 0)
 * - Automatically cancelled if the actor is deactivated
 * - Unregistered via {@link AbstractActor#unregisterActorTimer}
 *
 * The timer callback method receives the state data passed during registration and
 * the callback method name to invoke. The callback is routed through the actor's
 * method invocation system as a direct method call.
 *
 * @example
 * ```typescript
 * // Register a timer that fires after 1 second, then every 3 seconds,
 * // calling the "onTimer" method with custom state
 * const timer = new ActorTimerData(
 *   "cleanup-timer",
 *   "onTimer",
 *   1000,    // dueTime: 1 second
 *   3000,    // period: 3 seconds
 *   { sessionId: "sess-456" }
 * );
 * ```
 */
export default class ActorTimerData {
    /**
     * The user-defined name of this timer, unique within the actor instance.
     */
    readonly timerName: string;
    /**
     * Application-defined state data passed to the timer callback method.
     * Can be a JSON-serializable object or string.
     */
    readonly state: string | object | undefined;
    /**
     * The name of the callback method to invoke when the timer fires.
     * This method must exist on the actor implementation.
     */
    readonly callback: string;
    /**
     * Constructs an ActorTimerData instance.
     *
     * Note: The current implementation only supports basic timing with dueTime and period.
     * Time-to-live (TTL) and period are managed by the ActorManager, not this class.
     *
     * @param timerName - The name of the timer, unique within this actor.
     * @param callback - The name of the callback method to invoke.
     * @param state - Optional state data to be passed to the callback.
     *
     * @example
     * ```typescript
     * new ActorTimerData("session-timeout", "onSessionTimeout", { sessionId: "x" });
     * ```
     */
    constructor(timerName: string, callback: string, state?: string | object | undefined);
    /**
     * Retrieves the timer name.
     *
     * @returns The unique timer identifier within this actor.
     */
    getTimerName(): string;
    /**
     * Retrieves the timer state data.
     *
     * @returns The state passed during registration, or undefined if no state.
     */
    getState(): string | object | undefined;
    /**
     * Retrieves the callback method name.
     *
     * @returns The method name to be invoked when the timer fires.
     */
    getCallback(): string;
    /**
     * Converts this timer to a serializable object representation.
     *
     * Used internally for marshaling timer data during method invocation and
     * for passing to the timer callback handler.
     *
     * @returns An object with fields: callback, data.
     *
     * @internal
     */
    toObject(): object;
    /**
     * Reconstructs an ActorTimerData from a serialized object representation.
     *
     * Deserializes the state data using BufferSerializer to convert from Buffer
     * or JSON format to JavaScript values.
     *
     * @param timerName - The timer name.
     * @param obj - The serialized timer object (typically from actor runtime).
     * @returns A new ActorTimerData instance.
     *
     * @internal
     */
    static fromObject(timerName: string, obj: any): ActorTimerData;
}