(() => {
  'use strict';

  const headers = { 'Content-Type': 'application/json', 'x-lang': 'en' };

  async function request(path, options = {}) {
    const response = await fetch(path, {
      credentials: 'include',
      headers: { ...headers, ...(options.headers || {}) },
      ...options
    });
    const payload = await response.json().catch(() => ({}));
    if (!response.ok || payload.err) {
      throw new Error(payload.errorDetail || payload.message || 'The request could not be completed.');
    }
    return payload.data ?? payload;
  }

  function showToast(message, type = 'default') {
    const container = document.getElementById('toast-container');
    if (!container) return;
    const toast = document.createElement('div');
    toast.className = `toast${type === 'default' ? '' : ` toast--${type}`}`;
    toast.textContent = message;
    container.appendChild(toast);
    window.setTimeout(() => toast.remove(), 3000);
  }

  function updateCartCount(cart) {
    const count = Number(cart?.computed?.itemcount || 0);
    document.querySelectorAll('[data-cart-count]').forEach((badge) => {
      badge.textContent = String(count);
      badge.hidden = count === 0;
    });
  }

  async function refreshCart() {
    try {
      const cart = await request('/api/v1/cart/retrieve');
      updateCartCount(cart);
      return cart;
    } catch {
      return null;
    }
  }

  async function addToCart({ productId, skuId, vendorCode, quantity }) {
    if (!productId || !skuId || !vendorCode) {
      throw new Error('This book does not have a purchasable SKU.');
    }
    const cart = await request('/api/v1/cart/add', {
      method: 'POST',
      body: JSON.stringify({ productId, skuId, vendorCode, quantity })
    });
    updateCartCount(cart);
    showToast('Added to cart', 'success');
  }

  function bindCartButtons() {
    document.querySelectorAll('[data-add-to-cart]').forEach((button) => {
      button.addEventListener('click', async () => {
        button.disabled = true;
        try {
          await addToCart({
            productId: button.dataset.productId,
            skuId: button.dataset.skuId,
            vendorCode: button.dataset.vendorCode,
            quantity: 1
          });
        } catch (error) {
          showToast(error.message, 'error');
        } finally {
          button.disabled = false;
        }
      });
    });

    const detailButton = document.querySelector('[data-add-product]');
    const skuSelect = document.querySelector('[data-sku-select]');
    if (detailButton && skuSelect) {
      detailButton.addEventListener('click', async () => {
        const option = skuSelect.options[skuSelect.selectedIndex];
        const quantity = Math.max(1, Number(document.querySelector('[data-quantity]')?.value || 1));
        detailButton.disabled = true;
        try {
          await addToCart({
            productId: detailButton.dataset.productId,
            skuId: option.value,
            vendorCode: option.dataset.vendorCode,
            quantity
          });
        } catch (error) {
          showToast(error.message, 'error');
        } finally {
          detailButton.disabled = false;
        }
      });
    }
  }

  async function updateAccountLink() {
    try {
      const state = await request('/api/v1/account/customer/isloggedin');
      if (!state.isLoggedIn) return;
      document.querySelectorAll('[data-account-link]').forEach((link) => {
        link.href = '/api/v1/site/orders/history';
        link.querySelector('small').textContent = 'My account';
      });
    } catch {
      // Anonymous browsing is expected.
    }
  }

  document.querySelectorAll('[data-current-year]').forEach((node) => {
    node.textContent = String(new Date().getFullYear());
  });

  bindCartButtons();
  refreshCart();
  updateAccountLink();

  window.CampusBookHouse = { request, refreshCart, showToast, updateCartCount };
})();