// 1. API 기본 설정 -------------------------------------------------
const API_DOMAIN = 'YOUR_DOMAIN';
const API_KEY = 'YOUR_KEY';

const DEFAULT_PARAMS = {
  pagenum: 5,
  outcnt: 16,
  orderby: 'reg_edit', // reg_edit / hit
};

// 2. 쿼리스트링 유틸리티 ------------------------------------------
function toQueryString(params) {
  return Object.entries(params)
    .map(([key, value]) =>
      `${encodeURIComponent(key)}=${encodeURIComponent(value)}`
    )
    .join('&');
}

function buildBookListUrl(extraParams = {}) {
  const query = toQueryString({
    ...DEFAULT_PARAMS,
    ...extraParams,
  });

  return `https://${API_DOMAIN}/Web/Booklist?key=${API_KEY}&${query}`;
}

// 3. XML 응답을 자바스크립트 객체로 변환 ----------------------------
function parseBooks(xmlDocument) {
  const bookNodes = xmlDocument.querySelectorAll('book');

  return Array.from(bookNodes).map((book) => {
    const titleNode = book.querySelector('title');
    const thumbNode = book.querySelector('thumb_path');

    const rawTitle = titleNode ? titleNode.textContent : '';
    const rawThumb = thumbNode ? thumbNode.textContent : '';
    const code = book.getAttribute('code') || '';

    const thumb =
      rawThumb.trim().replace(/^\/\/, 'https://');

    return {
      code,
      title: rawTitle.trim(),
      thumb,
    };
  });
}

// 4. DOM 렌더링 (예시)
function renderBooks(books) {
    const container =
    document.getElementById('booklist');
  if (!container) {
    console.warn('[Booklist] 렌더링 대상 엘리먼트를 찾을 수 없습니다.');
    console.table(books);
    return;
  }

  container.innerHTML = '';

  if (!books.length) {
    container.textContent =
      '조회된 e-Book 콘텐츠가 없습니다.';
    return;
  }

  const list =
    document.createElement('ul');

  books.forEach((book) => {
    const item =
      document.createElement('li');
    item.textContent =
      `[${book.code}] ${book.title}`;
    list.appendChild(item);
  });

  container.appendChild(list);
}

// 5. 실제 API 호출 함수 (async/await)
async function fetchBookList(extraParams = {}) {
  const url = buildBookListUrl(extraParams);

  try {
    console.info('[Booklist] Request URL:', url);

    const response =
      await fetch(url);
    if (!response.ok) {
      throw new Error(
        `HTTP ${response.status} ${response.statusText}`
      );
    }

    const xmlText =
      await response.text();
    const xmlDoc =
      new window.DOMParser()
        .parseFromString(xmlText, 'text/xml');

    const books = parseBooks(xmlDoc);

    console.table(books);

    renderBooks(books);

    return books;
  } catch (error) {
    console.error('[Booklist] API Error:', error);
    return [];
  }
}

// 6. 페이지 로드 시 자동 실행 예시 -----------------------------------
document.addEventListener('DOMContentLoaded', () => {
  fetchBookList({
    pagenum: 1,
    outcnt: 6,

  });
});