export type SelectionVerdict = {
    eligible: true;
    text: string;
} | {
    eligible: false;
    reason: SelectionRejection;
};
export type SelectionRejection = "empty" | "too-short" | "too-long" | "editable" | "inside-assistant";
/** Roughly a word. Below this a double-click misfire is likelier than intent. */
export declare const MIN_SELECTION_CHARS = 3;
/**
 * A triple-click can select a whole page, and a page is not a question. The
 * cap is generous enough for a paragraph and short enough that what gets seeded
 * is still something a visitor would recognise as what they highlighted.
 */
export declare const MAX_SELECTION_CHARS = 600;
export type EligibilityInput = {
    text: string;
    /** True when the selection is inside an <input>, <textarea> or contenteditable. */
    isEditable: boolean;
    /** True when the selection is inside the assistant's own panel. */
    isInsideAssistant: boolean;
};
/**
 * Whether to offer.
 *
 * Every rejection is a rule from ADR 0202, and each one is about NOT offering
 * at a moment the visitor did not mean:
 *
 * - `editable`, they are writing, not reading. A selection inside a form field
 *   is almost always about editing it.
 * - `inside-assistant`, selecting part of an answer would offer to ask about
 *   the answer. Perhaps a feature one day; a footgun as a default.
 * - `too-short` / `too-long`, a double-click selects one word and a
 *   triple-click can select the page. Neither is a question.
 */
export declare function judgeSelection(input: EligibilityInput): SelectionVerdict;
/**
 * Read the current selection, crossing the shadow boundary where the platform
 * lets us.
 *
 * `window.getSelection()` does not describe selections that cross a shadow root
 * consistently across engines, the panel lives in one, so "is this selection
 * inside the assistant?" is exactly the question it answers badly.
 * `getComposedRanges()` is the standard answer and is feature-detected, because
 * it is not everywhere yet and the fallback is still correct for the ordinary
 * case of a visitor selecting text in the host page.
 */
export declare function readSelection(root?: ShadowRoot | null): {
    text: string;
    rect: DOMRect | null;
    node: Node | null;
};
/** True when the node sits inside a form field or contenteditable region. */
export declare function isEditableContext(node: Node | null): boolean;