/**
 * Tracks in-flight background tasks (run_in_background Bash/Agent) for a single
 * persistent Claude session, by observing the CLI's stream-json `system` events.
 *
 * Observed lifecycle (real shapes, see /tmp/bg-capture.mjs):
 *   - launch:     { type:'system', subtype:'task_started',      task_id, task_type }
 *   - completion: { type:'system', subtype:'task_updated',      task_id, patch:{status:'completed'} }
 *                 { type:'system', subtype:'task_notification', task_id, status:'completed', summary }
 *
 * IMPORTANT: task_updated{completed} and task_notification are TWO separate events, and the
 * CLI emits task_updated FIRST — sometimes seconds before the matching task_notification
 * (gaps up to ~24s observed when several run_in_background tasks finish close together).
 * task_notification is the one that actually re-invokes the model (the continuation turn).
 * So pending is keyed off task_notification ONLY; clearing on task_updated would let the
 * count hit 0 while continuation turns are still undelivered, sealing a turn "done"
 * prematurely (a continuation result resolving in that gap snapshots pendingCount==0).
 *
 * When a background task completes the CLI spontaneously re-invokes the model and
 * emits a fresh turn whose terminating `result` carries `origin.kind:'task-notification'`
 * (see isContinuationResult). The adapter uses pendingCount to decide whether a turn's
 * result should be sealed ("done") or held in a "waiting" state, and continuationArmed
 * to recognize the spontaneous continuation turn that follows.
 */
export declare class BgTaskTracker {
    private readonly pending;
    /** Set when a background task completes; the spontaneous continuation turn that
     *  follows is recognized via this flag. Cleared by disarmContinuation(). */
    continuationArmed: boolean;
    /** Observe one parsed stream-json event. Idempotent per task_id. */
    observe(data: any): void;
    get pendingCount(): number;
    hasPending(): boolean;
    disarmContinuation(): void;
}
/** A `result` event produced by a background-task continuation turn carries
 *  origin.kind === 'task-notification'. Used to distinguish a spontaneous
 *  continuation result from a normal turn result. */
export declare function isContinuationResult(data: any): boolean;
/** How a parsed stream-json line should be routed by the session's handleLine. */
export type LineRoute = 'normal' | 'open-continuation' | 'ignore';
/**
 * Decide how a parsed line should be routed given whether a turn is currently active.
 * Pure: depends only on the tracker's armed state and the event type.
 */
export declare function routeLine(tracker: BgTaskTracker, data: any, hasActiveTurn: boolean): LineRoute;