/**
 * One shared viewport-windowing rule for the pickers that overlay the chat
 * history (theme / autonomy / design / resume).
 *
 * Before this hook, every picker rendered every option as a static
 * `<Box flexDirection="column">`. That was fine for autonomy's 5 options but
 * started overflowing as soon as `/theme` carried 15 presets and `/resume`
 * could list 30+ sessions. The pickers live inside the scrollable chat
 * viewport — they share its row budget — so windowing has to be driven off
 * `useTerminalSize` and per-picker chrome, not a hardcoded count.
 *
 * The hook returns the inclusive `start` and exclusive `end` of the visible
 * slice plus `hasAbove` / `hasBelow` indicators the caller can render as
 * `…` markers. When the caller moves `selected`, the next call re-centers
 * the viewport on the new index — no imperative scroll needed.
 */
export interface UseWindowedPickerOptions {
    /** Total option count. */
    readonly total: number;
    /** Currently focused option index. The window re-centers on this. */
    readonly selected: number;
    /** Rows each option consumes (resume-picker entries take 3 lines). */
    readonly rowSpan?: number | undefined;
    /**
     * Rows the picker itself reserves around the list — top/bottom border,
     * header, hint, padding. Defaults to 4 which matches the current
     * `borderStyle="round"` + 2-line header pattern. Pass 0 for a naked list.
     *
     * This is a WORST-CASE reservation: the picker passes the maximum rows its
     * chrome can reach (including the `… more above/below` markers via
     * `markerRows`), so the window never overflows whether or not those
     * conditional rows actually render.
     */
    readonly chromeRows?: number | undefined;
    /**
     * Rows the conditional `… more above/below` marker lines consume when they
     * render. NOT part of `chromeRows` — a picker that shows both markers on a
     * 40-option list is 2 rows taller than its header+border chrome, and a
     * window sized against `chromeRows` alone overflows by exactly that many
     * rows. Pass the maximum marker count (2, plus 1 if a conditional hint row
     * exists) so the math reserves them up front.
     */
    readonly markerRows?: number | undefined;
    /**
     * Rows the surrounding app shell reserves — input bar + status bar + the
     * scrollable history's own chrome. Defaults to 6, which covers the input
     * bar (1), status bar (1), and a 4-row safety margin for header / hint /
     * padding. Bump this if your caller knows it needs more breathing room.
     *
     * Ignored when `maxRows` is provided — callers that can MEASURE the real
     * layout (e.g. app-view measuring the status bar + input heights) should
     * pass `maxRows` and drop this guess entirely.
     */
    readonly shellReservedRows?: number | undefined;
    /**
     * Exact row budget for the whole picker box, when the caller can measure
     * it (status bar + input + margins). Replaces the
     * `rows - shellReservedRows` guess: the window becomes
     * `floor((maxRows - chromeRows - markerRows) / rowSpan)` clamped to
     * `[minVisible, total]`. This is what makes the theme picker fit on a
     * 24-row terminal even when the input bar or status bar grows.
     */
    readonly maxRows?: number | undefined;
    /** Minimum visible options even on a tiny terminal. Defaults to 3. */
    readonly minVisible?: number | undefined;
}
export interface WindowedPickerSlice {
    /** Inclusive start index of the visible window. */
    readonly start: number;
    /** Exclusive end index of the visible window. */
    readonly end: number;
    /** True when at least one option is hidden above `start`. */
    readonly hasAbove: boolean;
    /** True when at least one option is hidden below `end - 1`. */
    readonly hasBelow: boolean;
}
/**
 * Compute a windowed slice of a picker list. Pure given the inputs — the only
 * "reactive" part is `useTerminalSize` so the window re-flows when the user
 * resizes their terminal while a picker is open.
 *
 * Behavior contract:
 *   - Visible count is `floor((available - chrome - markers) / rowSpan)`
 *     where `available` is either `maxRows` (measured) or
 *     `rows - shellReservedRows` (guessed), clamped to `[minVisible, total]`.
 *     A 1-row terminal always shows at least `minVisible` options even if
 *     that overflows — better to bleed than to hide the focused row.
 *   - The window stays centered on `selected` once the picker is past the
 *     first page; on the first page it stays top-aligned so the user sees
 *     the list start. `selected < 0 || selected >= total` is treated as no
 *     focus and the window anchors to index 0.
 *   - Empty / single-option lists always render `[0, total)` with both
 *     `hasAbove` and `hasBelow` false.
 *   - `maxRows` wins over `shellReservedRows`; when both are absent the
 *     legacy `rows - shellReservedRows` guess applies (backwards compatible).
 */
export declare function useWindowedPicker({ total, selected, rowSpan, chromeRows, markerRows, shellReservedRows, maxRows, minVisible, }: UseWindowedPickerOptions): WindowedPickerSlice;
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