// Basic logic for cart interactions
document.addEventListener('DOMContentLoaded', () => {
  const saleForm = document.querySelector('[data-sale-form]');
  if (!saleForm) return;

  let cart = [];
  const cartJsonInput = document.getElementById('cart_json');
  const cartLinesContainer = document.getElementById('cart-lines');
  const cartEmptyState = document.getElementById('cart-empty-state');
  const cartCountLabel = document.getElementById('cart-count-label');
  const cartSubtotalLabel = document.getElementById('cart-subtotal');
  const cartTotalLabel = document.getElementById('cart-total');

  function renderCart() {
    if (cart.length === 0) {
      cartEmptyState.style.display = 'block';
      cartLinesContainer.innerHTML = '';
      cartCountLabel.textContent = '0 ' + (window.saleLabels ? window.saleLabels.empty : 'items');
      cartSubtotalLabel.textContent = '0.00';
      cartTotalLabel.textContent = '0.00';
      cartJsonInput.value = '[]';
      return;
    }

    cartEmptyState.style.display = 'none';
    let html = '';
    let totalItems = 0;
    let subtotal = 0;

    cart.forEach((item, index) => {
      const lineTotal = item.qty * item.price;
      totalItems += item.qty;
      subtotal += lineTotal;
      
      html += `
        <div class="cart-line mb-2 p-2 border rounded bg-white shadow-sm d-flex justify-content-between align-items-center">
          <div>
            <div class="fw-semibold small">${item.name}</div>
            <div class="text-muted" style="font-size: 0.75rem;">${item.qty} x ${item.price.toFixed(3)}</div>
          </div>
          <div class="d-flex align-items-center gap-2">
            <span class="fw-bold text-primary">${lineTotal.toFixed(3)}</span>
            <div class="btn-group btn-group-sm">
              <button type="button" class="btn btn-outline-secondary" onclick="updateCartQty(${index}, -1)">-</button>
              <button type="button" class="btn btn-outline-secondary" onclick="updateCartQty(${index}, 1)">+</button>
              <button type="button" class="btn btn-outline-danger" onclick="removeCartItem(${index})"><i class="bi bi-trash"></i></button>
            </div>
          </div>
        </div>
      `;
    });

    cartLinesContainer.innerHTML = html;
    cartCountLabel.textContent = totalItems + ' items';
    cartSubtotalLabel.textContent = subtotal.toFixed(3);
    cartTotalLabel.textContent = subtotal.toFixed(3);
    cartJsonInput.value = JSON.stringify(cart);
  }

  window.updateCartQty = function(index, delta) {
    if (cart[index]) {
      cart[index].qty += delta;
      if (cart[index].qty <= 0) {
        cart.splice(index, 1);
      }
      renderCart();
    }
  };

  window.removeCartItem = function(index) {
    cart.splice(index, 1);
    renderCart();
  };

  document.querySelectorAll('[data-add-product]').forEach(btn => {
    btn.addEventListener('click', () => {
      const sku = btn.dataset.sku;
      const name = btn.dataset.name;
      const price = parseFloat(btn.dataset.price);

      const existing = cart.find(i => i.sku === sku);
      if (existing) {
        existing.qty++;
      } else {
        cart.push({ sku, name, price, qty: 1 });
      }
      
      // SweetAlert2 Toast for adding product
      if (typeof Swal !== 'undefined') {
        Swal.fire({
          toast: true,
          position: 'top-end',
          icon: 'success',
          title: name + ' added',
          showConfirmButton: false,
          timer: 1500
        });
      }
      
      renderCart();
    });
  });

  const clearBtn = document.querySelector('[data-clear-cart]');
  if (clearBtn) {
    clearBtn.addEventListener('click', () => {
      cart = [];
      renderCart();
    });
  }

  // Handle form submission warning if empty
  saleForm.addEventListener('submit', (e) => {
    if (cart.length === 0) {
      e.preventDefault();
      if (typeof Swal !== 'undefined') {
        Swal.fire('Empty Cart', 'Please add items before saving.', 'warning');
      } else {
        Swal.fire({icon: 'warning', text: 'Cart is empty'});
      }
    }
  });

  renderCart();
});