function dataCallback(data) {
  // Callback documentation:
  // https://fastspringexamples.com/callback/data-data-callback/

  //Automatically update the country selector to match the IP Geo-located country 
  // that FastSpring have detected that the buyer is visiting from.
  document.getElementById('country').value = data.country;
  isVATIDEnabled(data.country);
  
  if (data.taxExempt === true) {
     document.getElementById('vatid').disabled = true;
  } else {
    document.getElementById('reset').disabled = true;
  }
}

function changeCountry() {
  // Country selectory functionality
  
  orderCountry = document.getElementById('country').value;
  resetOrder();
  fastspring.builder.country(orderCountry);
  isVATIDEnabled(orderCountry);
}

function isVATIDEnabled(country) {
  // Only enable the VAT ID collection for European countries
  
  if (country === 'NL' || country === 'HR' || country === 'GB') {
    
       // Switch the page's product price to include tax or not
      document.getElementById('productPriceWithTax').style.display = "none";
      document.getElementById('productPriceWithoutTax').style.display = "block";
    
      document.getElementById('vatid').disabled = false;
      
    // Show the VAT ID ui elements
    [].forEach.call(document.querySelectorAll('.vat'), function (el) {
      el.style.display = "inline";
    });
    
    document.getElementById('vatP').style.display = "block";

  } else {
    document.getElementsByClassName('vat')[0].disabled = true;

      // Switch the page's product price to include tax or not
      document.getElementById('productPriceWithTax').style.display = "block";
      document.getElementById('productPriceWithoutTax').style.display = "none";
    
    // Hide the VAT ID ui elements
    [].forEach.call(document.querySelectorAll('.vat'), function (el) {
      el.style.display = "none";
    });
    
    document.getElementById('vatP').style.display = "none";
  }
}

function applyVATID() {
  taxid = document.getElementById('vatid').value;
  if (taxid) {
    fastspring.builder.taxId(taxid);
    document.getElementById('vatid').disabled = true;
    document.getElementById('applyVATButton').disabled = true;
    document.getElementById('reset').disabled = false;
    document.getElementById('vatResult').style.color = 'green';
    document.getElementById('vatResult').innerHTML = 'No VAT will be charged for this order.';
  }
}

function resetOrder() {
  fastspring.builder.reset();
  document.getElementById('vatid').value = "";
  document.getElementById('applyVATButton').disabled = false;
  document.getElementById('vatResult').style.color = 'grey';
  document.getElementById('vatResult').innerHTML = "Without a valid VAT ID, we will charge VAT in addition to the price.";
}

// Modal JavaScript
// ------------------------------------
var modal = document.getElementById("myModal");

// Get the button that opens the modal
var btn = document.getElementById("myBtn");

// Get the <span> element that closes the modal
var span = document.getElementsByClassName("close")[0];

// When the user clicks on the button, open the modal
btn.onclick = function() {
  modal.style.display = "block";
}

// When the user clicks on <span> (x), close the modal
span.onclick = function() {
  modal.style.display = "none";
}

// When the user clicks anywhere outside of the modal, close it
window.onclick = function(event) {
  if (event.target == modal) {
    modal.style.display = "none";
  }
}