/**
 * Exponential Backoff を使用して関数を実行する
 * 
 * @param {Function} fn - 実行する非同期関数
 * @param {number} maxRetries - 最大試行回数（デフォルト: 5）
 * @param {number} initialDelay - 初期遅延時間（ミリ秒、デフォルト: 500）
 * @param {number} maxDelay - 最大遅延時間（ミリ秒、デフォルト: 5000）
 * @param {number} multiplier - バックオフ乗数（デフォルト: 2）
 * @returns {Promise} - 関数の実行結果
 */
async function exponentialBackoff(
  fn,
  maxRetries = 3,
  initialDelay = 500,
  maxDelay = 5000,
  multiplier = 2
) {
  let lastError;
  
  for (let attempt = 0; attempt <= maxRetries; attempt++) {
    try {
      const result = await fn();
      return result;
    } catch (error) {
      lastError = error;
      
      // 最後の試行の場合はループを終了
      if (attempt === maxRetries) {
        break;
      }
      
      // バックオフ時間を計算 （ジッターを追加） して待機
      const baseDelay = Math.min(initialDelay * Math.pow(multiplier, attempt), maxDelay);
      const jitter = Math.random() * baseDelay * 0.1; // 0-10%のランダムなジッター
      const delay = baseDelay + jitter;
      await new Promise(resolve => setTimeout(resolve, delay));
    }
  }
  
  throw lastError;
}

/**
 * カードラインナップを取得する
 * 
 * @param {string[]} filters.categories - Categories to filter by
 * @param {string[]} filters.conditions - Conditions to filter by
 * @param {string} orders - Sort order
 * @param {number} limit - Limit of the results
 * @param {number} offset - Offset of the results
 * @returns {Promise<Object[]>} - Card lineup objects
 */
async function fetchCardLineup(filters, orders, limit = 100, offset = 0) {
  const params = new URLSearchParams();
  const filterParams = [];
  if (filters.categories) {
    params.append('filters', filters.categories.map((v) => `categories[contains]${v}`).join('[and]'));
  }
  if (filters.conditions) {
    params.append('filters', filters.conditions.map((v) => `conditions[contains]${v}`).join('[and]'));
  }
  if (filterParams.length > 0) {
    params.append('filters', filterParams.join('[and]'));
  }
  params.append('orders', orders);
  params.append('offset', offset);
  params.append('limit', limit);
  const response = await exponentialBackoff(() => fetch(`/microcms/api/v1/card-lineup?${params.toString()}`));
  const data = await response.json();
  return data;
}

/**
 * カードラインナップを全件取得する
 * カードラインナップを取得して、ジェネレーターで返します。呼び出し元は for 文を利用して全件を参照することができます。
 * 
 * @param {string[]} filters.categories - Categories to filter by
 * @param {string[]} filters.conditions - Conditions to filter by
 * @param {string} orders - Sort order
 * @returns {AsyncGenerator<Object>} - Async generator of card objects
 */
async function* scrollCardLineup(filters, orders) {
  const limit = 100;
  let offset = 0;
  let total = 0;
  do {
    const data = await fetchCardLineup(filters, orders, limit, offset);
    for (const card of data.contents) {
      yield card;
    };
    total = data.totalCount;
    offset += limit;
  } while (total > offset);
}

/**
 * カードラインナップを読み込む
 * 
 * @param {HTMLElement} parent - Parent element to append the cloned template
 * @param {HTMLTemplateElement} template - Template to clone
 * @param {string[]} filters.categories - Categories to filter by
 * @param {string[]} filters.conditions - Conditions to filter by
 * @param {string} orders - Sort order
 * @param {Function} options.callback - Callback function to execute after the template is cloned
 * @param {Object} options.queryParams - Query parameters to add to the URL
 */
async function loadCardLineup(parent, template, filters, orders, options = {}) {
  for await (const item of scrollCardLineup(filters, orders)) {
    if (!item) {
      continue;
    }

    const newClone = template.content.cloneNode(true);
    const link = newClone.querySelector('.__cms-link');
    if (link && item.lp_url) {
      if (options.queryParams) {
        link.href = `${item.lp_url}?${new URLSearchParams(options.queryParams).toString()}`;
      } else {
        link.href = item.lp_url;
      }
    }
    const bannerPC = newClone.querySelector('.__cms-banner-pc');
    if (bannerPC && item.banner_img_pc && item.banner_img_pc.url) {
      bannerPC.src = item.banner_img_pc.url;
      bannerPC.alt = item.banner_img_pc.alt || '';
    }
    const bannerSP = newClone.querySelector('.__cms-banner-sp');
    if (bannerSP && item.banner_img_sp && item.banner_img_sp.url) {
      bannerSP.src = item.banner_img_sp.url;
      bannerSP.alt = item.banner_img_sp.alt || '';
    }
    const title = newClone.querySelector('.__cms-title');
    if (title && item.title) {
      title.innerHTML = item.title.replace(/\n/g, '<br>');
    }
    const cardImage = newClone.querySelector('.__cms-card-image');
    if (cardImage && item.card_img && item.card_img.url) {
      cardImage.src = item.card_img.url;
      cardImage.alt = item.card_img.alt || '';
    }
    if (options.callback) {
      options.callback(newClone, item);
    }
    parent.appendChild(newClone);
  }
}

/**
 * お知らせを10件取得する
 * 
 * @param {string} category - Target to filter by
 * @param {string} orders - Sort order
 * @returns {Promise<Object[]>} - お知らせ一覧
 */
async function fetchNotifications(category, orders = '+publishedAt') {
  const params = new URLSearchParams();
  params.append('filters', `categories[contains]${category}`);
  params.append('orders', orders);
  params.append('limit', 10);
  const response = await fetch(`/microcms/api/v1/epnt-notifications?${params.toString()}`);
  const data = await response.json();
  return data.contents;
}

/**
 * お知らせを読み込む
 * 
 * @param {HTMLElement} parent - Parent element to append the cloned template
 * @param {HTMLTemplateElement} template - Template to clone
 * @param {string} category - Category to filter by
 * @param {string} orders - Sort order
 */
async function loadNotifications(parent, template, category, orders) {
  const notifications = await fetchNotifications(category, orders);
  notifications.forEach((item) => {
    const newClone = template.content.cloneNode(true);
    const content = newClone.querySelector('.__cms-notification-content');
    if (content && item.content) {
      content.innerHTML = item.content;
    }
    parent.appendChild(newClone);
  });
}

/**
 * 残価クレジットのお知らせを10件取得する
 * 
 * @returns {Promise<Object[]>} - お知らせ一覧
 */
async function fetchAFSLoanNotifications() {
  const params = new URLSearchParams();
  params.append('orders', '-publishedAt');
  params.append('limit', 10);
  const response = await fetch(`/microcms/api/v1/afsloan-notifications?${params.toString()}`);
  const data = await response.json();
  return data.contents;
}