// helper: convert number to Indian-notation words (Crore, Lakh, Thousand, Hundred)
function numberToWords(num) {
  const small = ['', 'One', 'Two', 'Three', 'Four', 'Five', 'Six', 'Seven', 'Eight', 'Nine',
    'Ten', 'Eleven', 'Twelve', 'Thirteen', 'Fourteen', 'Fifteen', 'Sixteen', 'Seventeen', 'Eighteen', 'Nineteen'];
  const tens = ['', '', 'Twenty', 'Thirty', 'Forty', 'Fifty', 'Sixty', 'Seventy', 'Eighty', 'Ninety'];
  function twoDigit(n) {
    if (n < 20) return small[n];
    return tens[Math.floor(n / 10)] + (n % 10 ? ' ' + small[n % 10] : '');
  }
  let words = '';
  const crore = Math.floor(num / 10000000); num %= 10000000;
  if (crore) words += twoDigit(crore) + ' Crore ';
  const lakh = Math.floor(num / 100000); num %= 100000;
  if (lakh) words += twoDigit(lakh) + ' Lakh ';
  const thousand = Math.floor(num / 1000); num %= 1000;
  if (thousand) words += twoDigit(thousand) + ' Thousand ';
  const hundred = Math.floor(num / 100); num %= 100;
  if (hundred) words += small[hundred] + ' Hundred ';
  if (num) words += (words ? 'and ' : '') + twoDigit(num) + ' ';
  return words.trim() || 'Zero';
}

if (typeof document !== 'undefined') {
  document.addEventListener('DOMContentLoaded', function () {
    const addItemBtn = document.getElementById('add-item');
    const itemsTableBody = document.querySelector('#items-table tbody');
    const form = document.getElementById('quotation-form');
    const output = document.getElementById('quotation-output');

    function updateSerialNumbers() {
      itemsTableBody.querySelectorAll('tr').forEach((row, i) => {
        row.querySelector('.item-slno').textContent = i + 1;
      });
    }

    function addItemRow() {
      const row = document.createElement('tr');
      row.innerHTML = `
        <td class="item-slno" data-label="S.No"></td>
        <td data-label="Description"><input type="text" class="item-desc" placeholder="Item Description" required></td>
        <td data-label="HSN Code"><input type="text" class="item-hsn" placeholder="HSN Code"></td>
        <td data-label="Qty"><input type="number" class="item-qty" value="1" min="0" required></td>
        <td data-label="Unit Price"><input type="number" class="item-price" value="0" min="0" required></td>
        <td data-label="Discount (%)"><input type="number" class="item-discount" value="0" min="0" max="100" step="0.01" placeholder="Discount %"></td>
        <td class="item-amount" data-label="Amount">0.00</td>
        <td data-label="Action"><button type="button" class="remove-item">Remove</button></td>
      `;
      itemsTableBody.appendChild(row);
      updateSerialNumbers();
      const inputs = row.querySelectorAll('input');
      inputs.forEach(input => input.addEventListener('input', updateItemAmount));
      row.querySelector('.remove-item').addEventListener('click', () => {
        row.remove();
        updateSerialNumbers();
      });
    }

    function updateItemAmount(e) {
      const row = e.target.closest('tr');
      const qty = parseFloat(row.querySelector('.item-qty').value) || 0;
      const price = parseFloat(row.querySelector('.item-price').value) || 0;
      const discountRate = parseFloat(row.querySelector('.item-discount').value) || 0;
      const discountAmount = qty * price * discountRate / 100;
      const amount = qty * price - discountAmount;
      row.querySelector('.item-amount').textContent = amount.toFixed(2);
    }

    addItemBtn.addEventListener('click', addItemRow);

    form.addEventListener('submit', function (e) {
      e.preventDefault();
      const data = new FormData(form);
      const company = {
        name: data.get('company-name'),
        address: data.get('company-address'),
        phone: data.get('company-phone'),
        email: data.get('company-email'),
        gstin: data.get('company-gstin')
      };
      const customer = {
        name: data.get('customer-name'),
        address: data.get('customer-address'),
        phone: data.get('customer-phone'),
        email: data.get('customer-email'),
        gstin: data.get('customer-gstin')
      };
      const quotationNumber = data.get('quotation-number');
      const quotationDate = data.get('quotation-date');
      const igstRate = parseFloat(data.get('igst-rate')) || 0;
      const freightCharges = parseFloat(data.get('freight-charges')) || 0;
      const bank = {
        name: data.get('bank-name'),
        account: data.get('bank-account'),
        ifsc: data.get('bank-ifsc'),
        branch: data.get('bank-branch')
      };
      const items = [];
      itemsTableBody.querySelectorAll('tr').forEach(row => {
        items.push({
          description: row.querySelector('.item-desc').value,
          hsn: row.querySelector('.item-hsn').value,
          qty: parseFloat(row.querySelector('.item-qty').value) || 0,
          price: parseFloat(row.querySelector('.item-price').value) || 0,
          discount: parseFloat(row.querySelector('.item-discount').value) || 0,
          amount: parseFloat(row.querySelector('.item-amount').textContent) || 0
        });
      });
      const { subtotal, igstAmount, _total, rOff, finalTotal } = calculateQuotation(items, igstRate, freightCharges);

      // convert total to words (Rupees and Paise)
      const rupeePart = Math.floor(finalTotal);
      const paisePart = Math.round((finalTotal - rupeePart) * 100);
      const rupeeWords = numberToWords(rupeePart);
      const paiseWords = paisePart > 0 ? numberToWords(paisePart) : '';

      let html = `
        <div class="quotation-print">
          <div class="header">
            <div class="company-details">
              <strong>${company.name}</strong><br>
              {{address}}<br>
              GST NO. : ${company.gstin || ''}<br>
              CONTACT NO : ${company.phone} ${company.email}
            </div>
            <div class="quotation-title">
              <h1>QUOTATION</h1>
              <table class="quote-meta">
                <tr>
                  <td>QUO. NO</td>
                  <td>${quotationNumber}</td>
                </tr>
                <tr>
                  <td>DATE</td>
                  <td>${quotationDate}</td>
                </tr>
              </table>
            </div>
          </div>

          <div class="customer-info">
            <strong>CUSTOMER INFO</strong><br>
            ${customer.name}<br>
            {{cutomer_address}}<br>
            GST NO. : ${customer.gstin || ''}<br>
            CONTACT NO : ${customer.phone} ${customer.email}
          </div>

          <table class="items-table-print">
            <thead>
              <tr>
                <th>SL NO</th>
                <th>DESCRIPTION</th>
                <th>HSN CODE</th>
                <th>QTY</th>
                <th>UNIT PRICE</th>
                <th>DISCOUNT</th>
                <th>AMOUNT</th>
              </tr>
            </thead>
            <tbody>
      `;
      items.forEach((item, idx) => {
        html += `
              <tr>
                <td>${idx + 1}</td>
                <td>${item.description}</td>
                <td>${item.hsn}</td>
                <td>${item.qty}</td>
                <td>${item.price.toFixed(2)}</td>
                <td>${item.discount.toFixed(2)}%</td>
                <td>${item.amount.toFixed(2)}</td>
              </tr>
        `;
      });
      // Add empty rows to fill the page
      for (let i = items.length; i < 10; i++) {
        html += '<tr><td>&nbsp;</td><td></td><td></td><td></td><td></td><td></td><td></td></tr>';
      }

      html += `
            </tbody>
          </table>

          <div class="footer">
            <div class="notes-and-total">
              <div class="notes">
                SPECIAL NOTES:<br><br>
                AMOUNT IN WORDS:<br>
                <strong>${rupeeWords}${paiseWords ? ' and ' + paiseWords + ' Paise' : ''} only</strong><br><br>
                Delivery : 7 To 10 working days after receiving PO<br><br>
                BANK DETAILS FOR RTGS/ NEFT ${bank.name}, BRANCH: ${bank.branch}<br>
                A/C NO: ${bank.account}<br>
                IFSC CODE: ${bank.ifsc}
              </div>
              <div class="totals">
                <table>
                  <tr>
                    <td>SUB TOTAL</td>
                    <td>${subtotal.toFixed(2)}</td>
                  </tr>
                  <tr>
                    <td>FREIGHT CHARGES</td>
                    <td>${freightCharges.toFixed(2)}</td>
                  </tr>
                  <tr>
                    <td>IGST</td>
                    <td>${igstAmount.toFixed(2)}</td>
                  </tr>
                  <tr>
                    <td>R/OFF</td>
                    <td>${rOff.toFixed(2)}</td>
                  </tr>
                  <tr>
                    <td><strong>TOTAL</strong></td>
                    <td><strong>${finalTotal.toFixed(2)}</strong></td>
                  </tr>
                </table>
              </div>
            </div>
            <div class="disclaimer">
              This quotation is not a contract or a bill. It is our best guess at the total price for the service and goods described above. The customer will be billed after indicating acceptance of this quote. Payment will be due prior to the delivery of service and goods. Please fax or mail the signed quote to the address listed above.
            </div>
            <div class="thank-you">
              Thank you for your business!
            </div>
          </div>
          <button onclick="window.print()">Print / Save as PDF</button>
        </div>
      `;
      html = html.replace('{{address}}', company.address.replace(/\n/g, '<br>'));
      html = html.replace('{{cutomer_address}}', company.address.replace(/\n/g, '<br>'));
      output.innerHTML = html;
      output.style.display = 'block';
      document.getElementById('form-container').style.display = 'none';
      addItemRow();
    });
  });
}

function calculateQuotation(items, igstRate, freightCharges) {
  const subtotal = items.reduce((sum, i) => sum + i.amount, 0);
  const igstAmount = (subtotal * igstRate) / 100;
  const total = subtotal + igstAmount + freightCharges;
  const totalBeforeRoundOff = total;
  const finalTotal = Math.round(totalBeforeRoundOff);
  const rOff = totalBeforeRoundOff - finalTotal;

  return {
    subtotal,
    igstAmount,
    total,
    rOff,
    finalTotal
  };
}

// Export for testing (Node.js)
if (typeof module !== 'undefined' && module.exports) {
  module.exports = { numberToWords, calculateQuotation };
}