/**
 * In-memory, per-session buffer of opencode messages + parts.
 *
 * opencode plugins run in-process in the long-lived server, so — unlike
 * weave-codex, which reads an append-only rollout file with a byte cursor — we
 * accumulate the structured event stream directly. `takeCompletedTurns()` is the
 * cursor's moral equivalent: it returns turns that look fully flushed and not
 * yet emitted, marks them emitted, and prunes their messages so the buffer stays
 * bounded over a long session. Pure and synchronous; the plugin owns I/O.
 */
import type { ReconstructedTurn } from '../model.js';
import { type OcEvent } from './types.js';
export declare class Accumulator {
    private readonly sessions;
    /** Feed one opencode event. Unknown event types are ignored. */
    ingest(event: OcEvent): void;
    /**
     * Return turns for `sessionId` that are complete and not yet emitted, marking
     * them emitted and pruning their messages. Call this on `session.idle`.
     */
    takeCompletedTurns(sessionId: string): ReconstructedTurn[];
    /** Drop a session's buffer entirely (e.g. on session end / error cleanup). */
    forget(sessionId: string): void;
    private snapshot;
    private buffer;
    private dropMessage;
}