/**

* 인터랙티브 목록 선택 유틸리티

*

* 번호 선택, /키워드 필터, all(전체 복원), 0(취소)을 지원합니다.

*/

type WriteFn = (message: string) => void;

export interface ChoicePrompt {

ask: (question: string) => Promise<string>;

}

interface PickerOptions<T> {

prompt: ChoicePrompt;

writeOut: WriteFn;

title: string;

emptyText: string;

cancelText: string;

items: T[];

renderItem: (item: T, index: number) => string;

indexText?: string;

filterText?: (item: T) => string;

}

function normalize(value: string): string {

return value.toLowerCase();

}

function defaultFilterText<T>(item: T): string {

return typeof item === 'string' ? item : JSON.stringify(item);

}

export async function pickFromList<T>(options: PickerOptions<T>): Promise<T | null> {

const {

prompt,

writeOut,

title,

emptyText,

cancelText,

items,

renderItem,

indexText = '입력: 번호 선택 | /키워드 필터 | all 전체보기 | 0 취소',

filterText = defaultFilterText,

} = options;

if (items.length === 0) {

writeOut(emptyText);

return null;

}

let visibleItems = items;

while (true) {

writeOut('');

writeOut(title);

for (let i = 0; i < visibleItems.length; i += 1) {

writeOut(renderItem(visibleItems[i], i));

}

writeOut(indexText);

const answer = await prompt.ask('선택: ');

if (answer === '0') {

writeOut(cancelText);

return null;

}

if (answer === 'all') {

visibleItems = items;

continue;

}

if (answer.startsWith('/')) {

const query = answer.slice(1).trim();

if (!query) {

visibleItems = items;

continue;

}

const needle = normalize(query);

const filtered = items.filter((item) => normalize(filterText(item)).includes(needle));

if (filtered.length === 0) {

writeOut(`"${query}" 검색 결과가 없습니다.`);

continue;

}

visibleItems = filtered;

continue;

}

const picked = Number.parseInt(answer, 10);

if (Number.isNaN(picked) || picked < 1 || picked > visibleItems.length) {

continue;

}

return visibleItems[picked - 1];

}

}