function fontLinkToBase64(link) {
  return new Promise(function(resolve, reject) {
    $.get(link, function(data, status, xhr){
      var contentType = xhr.getResponseHeader('content-type');
      const base64Data = 'data:' + contentType + ';charset=utf-8;base64,' + btoa(unescape(encodeURIComponent(data)));
      const dataObj = {
        link: link,
        base64: base64Data
      }
      resolve(dataObj);
    });
  });
}

function getProcessedCSS(css) {
  return new Promise(function(resolve, reject) {
    const fontLinkRegex = new RegExp(/(https?:\/\/(fonts\.)[a-zA-Z0-9][a-zA-Z0-9-]+[a-zA-Z0-9]\.[^\s]{2,})\w/, 'ig');
    const matches = css.match(fontLinkRegex);

    // BUG: the last url always throws errors when converted to base64 for some reason.
    matches.splice(-1,1);

    var promises = [];

    matches.forEach(function(link) {
      promises.push(fontLinkToBase64(link));
    });

    Promise.all(promises).then(function(fontData) {
      fontData.forEach(function(data) {
        css = css.replace(data.link, data.base64);
      });
      resolve(css);
    });
  });
}

window.onload = function() {
  
  const fontInput = $('#font-input');
  const textarea = $('#processed-css');

  $('#font-btn').on('click', function() {
    const url = fontInput.val();
    
    $.get(url, function(css) {
			getProcessedCSS(css).then(function(processedCSS) {
				textarea.val(processedCSS);
			});
		});
  });
  
};