import { BaseCheckpointSaver } from '@langchain/langgraph';
import { type HistoryConfigView } from '#src/history/historyEnabled.js';
/** The checkpointer a session drives, plus what the session needs to know about it. */
export interface SessionCheckpointer {
    /** The saver to hand to `GthAgentRunner.init` / `GthAgentInterface.init`. Never null. */
    saver: BaseCheckpointSaver;
    /**
     * True when checkpoints are reaching disk — i.e. when this session can be resumed later. False
     * for a `MemorySaver`, whether that is the deliberate opt-out or the fallback.
     */
    durable: boolean;
    /**
     * The LangGraph thread this session's state is stored under, minted here so the conversation row
     * can record it BEFORE the runner is initialised — `init` can throw partway, and a conversation
     * whose thread id was never written is a listing entry that can never be resumed.
     */
    threadId: string;
    /**
     * Name the conversation row this session's turns group under, so a later checkpoint-write failure
     * can mark it unresumable ON DISK. Call once per conversation the session records under:
     * immediately after `openConversationSafe`, and again when a mid-session `/resume` moves the
     * session onto another conversation — the saver is the same, so the row it would mark has to
     * follow the session. Passing `undefined` (history off, or the row could not be opened) is fine
     * and simply leaves nothing to mark. Safe to call before or after a failure has already happened
     * — a failure that arrives first is applied here instead, and a rebind after one marks the new
     * row too, which is correct: a saver that has stopped writing is truncating whichever
     * conversation it is now on. Never throws.
     *
     * **Optional on the interface, and called with `?.`**, because a dozen-odd specs stub
     * `openSessionCheckpointerSafe` with a plain object literal to keep a session off the real
     * database. Requiring it would break every one of them at runtime for no gain: a stub that omits
     * it simply has no conversation to mark, which is the correct behaviour for a test that is not
     * about this.
     */
    bindConversation?(conversationId: number | undefined): void;
    /**
     * GS2-106 — whether a checkpoint write has failed in this session, so its conversation's link
     * has been (or, once bound, will be) cut. A single-shot run reads it before printing its continue
     * hint: a hint naming a conversation whose link was just cut would name an id that refuses.
     * Optional for the same reason as {@link bindConversation}.
     */
    isDegraded?(): boolean;
    /** Release the underlying connection (a no-op when the saver is in memory). Never throws. */
    close(): void;
}
export interface OpenSessionCheckpointerOptions {
    /** Drive a specific thread instead of a fresh one — how a resume re-enters a stored thread. */
    threadId?: string;
    /**
     * Where the fallback notice goes. Defaults to {@link displayWarning}; injectable so a caller on a
     * managed surface can route it, and so a test can read it without mocking the console.
     */
    notify?: (message: string) => void;
}
export declare function openSessionCheckpointerSafe(config: HistoryConfigView, options?: OpenSessionCheckpointerOptions): SessionCheckpointer;