/** Stable-anchor paging and folding. The operation supplies the full-response budget check. */
import { Type, type Static } from "typebox";
import { type Outcome } from "../tools/result.js";
import { type HistoryEvent, type HistoryFilter, type HistoryPageItem, type HistoryProjection } from "./history.js";
type Candidate = {
    event: HistoryEvent;
    matchOffset?: number;
    preview?: HistoryPageItem;
};
type AnchorParams = {
    before?: number;
    after?: number;
    limit?: number;
    max_chars_per_item?: number;
};
export declare const HistoryPageSchema: Type.TObject<{
    items: Type.TArray<Type.TUnion<[Type.TObject<{
        seq: Type.TInteger;
        window_id: Type.TString;
        role: Type.TUnion<[Type.TLiteral<"user">, Type.TLiteral<"assistant">, Type.TLiteral<"tool">, Type.TLiteral<"context">]>;
        created_at: Type.TUnion<[Type.TString, Type.TNull]>;
        tool: Type.TOptional<Type.TString>;
        tool_name_omitted: Type.TOptional<Type.TBoolean>;
        tool_status: Type.TOptional<Type.TUnion<[Type.TLiteral<"ok">, Type.TLiteral<"error">, Type.TLiteral<"unfinished">]>>;
        output_truncated: Type.TOptional<Type.TBoolean>;
        full_output_path: Type.TOptional<Type.TUnion<[Type.TString, Type.TNull]>>;
        nested_calls: Type.TOptional<Type.TObject<{
            call_count: Type.TInteger;
            complete: Type.TBoolean;
        }>>;
        truncated: Type.TBoolean;
        total_chars: Type.TInteger;
        content: Type.TString;
        offset_chars: Type.TOptional<Type.TInteger>;
    }>, Type.TObject<{
        folded: Type.TLiteral<true>;
        first_seq: Type.TInteger;
        last_seq: Type.TInteger;
        count: Type.TInteger;
        tools: Type.TRecord<"^.*$", Type.TInteger>;
        omitted_tools: Type.TOptional<Type.TInteger>;
    }>]>>;
    older_before: Type.TUnion<[Type.TInteger, Type.TNull]>;
    newer_after: Type.TUnion<[Type.TInteger, Type.TNull]>;
}>;
/** One whole page payload, before it becomes an outcome. */
export type HistoryPage = Static<typeof HistoryPageSchema>;
export declare function isConversationView(params: HistoryFilter): boolean;
/** Grow the page in query order; shorten the first preview only when no full row fits. */
export declare function selectPage(projection: HistoryProjection, params: HistoryFilter & AnchorParams, vis: Candidate[], folds: boolean, fits: (page: HistoryPage) => boolean, maxChars: number): Outcome<HistoryPage>;
export {};