import type { SessionChanges } from '../../../../services/agent-mon/model/session-changes.type.js';
import type { ViewModel } from './view-model.type.js';
/**
 * @purpose Public interface of the state manager — query current ViewModel and subscribe to updates.
 * @invariant getViewModel() always returns the latest snapshot; subscribe fires immediately with current state.
 */
export type StateManager = {
    /**
     * @purpose Retrieve the current ViewModel snapshot.
     * @returns Current immutable copy.
     */
    getViewModel(): ViewModel;
    /**
     * @purpose Register a callback invoked on every ViewModel update, including the current state immediately.
     * @param fn Callback receiving the updated ViewModel.
     * @returns Unsubscribe function — call to stop receiving updates.
     */
    subscribe(fn: (vm: ViewModel) => void): () => void;
};
/**
 * @purpose Create a state manager that consumes SessionChanges from an async iterable.
 * @implements {StateManager} in ./create-state-manager.ts
 * @invariant Subscribers receive the current ViewModel immediately on subscribe; status='loading' until first iteration.
 * @invariant On observer error: status transitions to 'error', data preserves last successful scan.
 * @param changes Async iterable of SessionChanges — produced by the agent-mon observe() pipeline.
 * @param [opts] Optional configuration to control per-provider session limit.
 * @returns StateManager instance with getViewModel and subscribe methods.
 * @sideEffect Spawns background async iteration over changes; notifies subscribers on each update.
 */
export declare function createStateManager(changes: AsyncIterable<SessionChanges>, opts?: {
    limit?: number;
}): StateManager;