import type { Screen } from '../Screen';
import type { MentionSuggestion } from '../../utils/mentions';
export interface MentionPickerState {
    open: boolean;
    index: number;
    items: MentionSuggestion[];
    /** Index of the `@` in the editor value at the time the query started. */
    atStart: number;
    /** Project root used to resolve suggestions (cached per update). */
    root: string;
}
export declare function createMentionPickerState(): MentionPickerState;
/** Set the picker to a fresh query result. */
export declare function openMentionPicker(state: MentionPickerState, items: MentionSuggestion[], atStart: number, root: string): MentionPickerState;
/** Close the picker and clear its items. */
export declare function closeMentionPicker(state: MentionPickerState): MentionPickerState;
/** Minimal key shape App's KeyEvent satisfies. */
export interface MentionPickerKeyEvent {
    key: string;
}
/** What App should do after a key press. */
export type MentionPickerAction = {
    type: 'none';
} | {
    type: 'close';
} | {
    type: 'navigate';
    delta: -1 | 1;
} | {
    type: 'select';
    suggestion: MentionSuggestion;
    atStart: number;
};
/**
 * Handle one key event while the mention picker is open. Returns the next
 * state plus an action; `select` carries the chosen suggestion and the
 * `@` index so App can rewrite the editor buffer.
 */
export declare function handleMentionPickerKey(state: MentionPickerState, event: MentionPickerKeyEvent): {
    state: MentionPickerState;
    action: MentionPickerAction;
};
/**
 * Compute the editor buffer after applying a mention selection. Pure:
 * returns the next value + cursor position for App to set.
 *
 * `atStart` is the index OF the `@`, so the `before` slice EXCLUDES it —
 * the sigil is re-added or the completed path is no longer a mention and
 * the file never gets attached.
 */
export declare function applyMentionToBuffer(value: string, cursor: number, atStart: number, suggestion: MentionSuggestion): {
    value: string;
    cursor: number;
};
/**
 * Paint the mention picker below the status bar. Mirrors the layout of the
 * `/` Autocomplete (separator → title → items → footer) but shows file
 * paths with their parent directory as the description, and an `@` prefix.
 */
export declare function renderMentionPicker(screen: Screen, state: MentionPickerState, startY: number): void;