/**
 * WHICH UNIT IS WORST, AND WHICH HAS BEEN THAT WAY LONGEST — the live board's
 * one ordering, as a function.
 *
 * It lives in the kit and not in a screen for the reason the countdown
 * (`deadline.ts`) does: "the exception is a row, ranked by severity then age" is
 * a contract, and a board that re-picks the ladder for itself says a unit is
 * urgent at a different distance than the board beside it. It is RN- and
 * React-free so the rule can be read against its cases rather than through a
 * rendered grid.
 *
 * TWO INPUTS, IN THIS ORDER, and the order is the finding: a unit the model has
 * FLAGGED outranks one whose reading has merely crossed its bound. A flag is
 * somebody's answer about the unit — it is off the road, the alarm went — where a
 * bound is arithmetic that crosses back on its own the moment the next reading
 * lands. Ranked the other way, one over-full bay outranks every breakdown on the
 * board.
 */
/** The conditions a unit can be in, WORST FIRST — the ladder the board reads by. */
export declare const BOARD_CONDITIONS: readonly ["flagged", "past", "steady"];
export type BoardCondition = (typeof BOARD_CONDITIONS)[number];
/** Where a unit stands, and since when — everything the ordering reads. */
export interface BoardStanding {
    condition: BoardCondition;
    /**
     * The day the unit entered the condition it is in, as the field stores it
     * (ISO, so it orders as text). Absent where nothing recorded one, which puts
     * the unit LAST inside its own condition: an undated exception cannot be shown
     * to be older than a dated one, and guessing either way reorders the rail on a
     * fact nobody has.
     */
    since?: string | null;
}
/**
 * WHICH CONDITION A UNIT IS IN — the model's own flag, then the reading that has
 * crossed the bound it is read against.
 *
 * A flag nobody has answered is not a `false`: both are "not flagged" for the
 * ladder, and the difference is what the row's own mark draws.
 */
export declare function boardCondition(flagged: boolean | null | undefined, past: boolean): BoardCondition;
/**
 * THE UNITS IN THE ORDER THE BOARD READS THEM — worst first, and inside one
 * condition the longest-standing first.
 *
 * A COPY, always: the rows are the caller's read and the board is one of several
 * surfaces over them, so sorting the array in place would reorder the register
 * the caller drew from the same read.
 *
 * Ties break on the order the rows ARRIVED, stated rather than left to the
 * engine: two units flagged on the same day have nothing left to rank them by,
 * and a board whose rows swap places between renders is one the reader cannot
 * point at.
 */
export declare function rankUnits<T>(rows: readonly T[], standing: (row: T) => BoardStanding): T[];