/**
 * Persisted-history pruning after compaction: derive the kept branch
 * message signatures, match them against SQLite history, and delete the
 * pruned remainder after a successful compaction_end. Bodies moved
 * verbatim from `session-stream.ts`.
 */
import type { BridgeLike } from "../session-stream.js";
import type { SessionStore } from "../storage.js";
import type { ServerEvent, WireMessage } from "../wire.js";
export type CompactionEndPruneSkipReason = "aborted" | "skipped" | "failed" | "missing_token_reduction";
export declare function getCompactionEndPruneSkipReason(event: Extract<ServerEvent, {
    type: "compaction_end";
}>): CompactionEndPruneSkipReason | null;
export type BranchEntryLike = NonNullable<ReturnType<NonNullable<BridgeLike["getSessionBranch"]>>>[number];
export type PersistedConversationRole = "user" | "assistant";
export interface KeptBranchMessageSignature {
    role: PersistedConversationRole;
    content: string;
    timestampMs: number | null;
    entryId: string;
}
export interface ExistingConversationMessage {
    message: WireMessage;
    conversationIndex: number;
}
export declare function isRecord(value: unknown): value is Record<string, unknown>;
export declare function contentAsPersistedText(content: unknown): string | null;
export declare function branchMessageTimestampMs(entry: BranchEntryLike, message: Record<string, unknown>): number | null;
export declare function branchMessageSignature(entry: BranchEntryLike): KeptBranchMessageSignature | null;
export declare function branchMessageRole(entry: BranchEntryLike): unknown;
export declare function getKeptBranchMessageSignatures(entries: BranchEntryLike[], keptEntryIndex: number): KeptBranchMessageSignature[] | null;
export declare function selectUniqueCandidate(candidates: ExistingConversationMessage[], kept: KeptBranchMessageSignature): ExistingConversationMessage | null;
export declare function matchKeptPersistedMessageIds(existing: WireMessage[], keptBranchMessages: KeptBranchMessageSignature[]): Set<string> | null;
export declare function prunePersistedHistoryAfterCompaction(store: SessionStore, sessionId: string, bridge: BridgeLike): void;
//# sourceMappingURL=history-prune.d.ts.map