import type { SessionTreeNode } from "./sessions-group.js";
/** Display disclosure is independent of API page size and retained page caches. */
export declare const SESSION_GROUP_VISIBLE_STEP = 4;
/** One rendered, expanded session group that can use spare rail height. */
export type SessionGroupFillCandidate = {
    key: string;
    /** Root rows already loaded for the group. */
    loaded: number;
    /** Rows shown without automatic fill: the initial step or a manual disclosure. */
    base: number;
    /** The server can return more rows for this group. */
    hasMore: boolean;
};
/**
 * Plan the extra rows each group shows to use spare rail height.
 *
 * Spare rows go top-down to groups that still hide rows. Rows already planned
 * or restored but not loaded yet count against the spare space, so slow pages
 * never cause over-allocation. Rows are taken back bottom-up only when `shrink` is set
 * (the rail viewport itself got shorter); content growth from manual
 * disclosure or new sessions never retracts rows the reader can already see.
 * Groups absent from `candidates` (collapsed or no longer rendered) drop
 * their fill.
 */
export declare function planSessionGroupFill(candidates: readonly SessionGroupFillCandidate[], current: ReadonlyMap<string, number>, freeRows: number, shrink: boolean): Map<string, number>;
/** True when two fill plans show the same rows. */
export declare function sameSessionGroupFill(left: ReadonlyMap<string, number>, right: ReadonlyMap<string, number>): boolean;
/** Fill a display step even when it straddles the retained server page. */
export declare function sessionGroupDisclosurePlan(visibleCount: number, loadedCount: number, hasMore: boolean, failed: boolean): {
    nextCount: number;
    needsPage: boolean;
};
/** Keep the selected workstream visible without exceeding the group's window. */
export declare function sessionGroupWindowNodes(nodes: readonly SessionTreeNode[], visibleCount: number, selectedSessionId: string | null): SessionTreeNode[];