function getCurrentDate() {
  let today = new Date();
  let yyyy = today.getFullYear();
  let mm = String(today.getMonth() + 1).padStart(2, '0'); //January is 0!
  let dd = String(today.getDate()).padStart(2, '0');
  return yyyy + "-" + mm + "-" + dd;
}

function extractFileUrlsAndNames() {
  return [];
}

function onStartedDownload(id) {
  console.log(`Started downloading: ${id}`);
}

function onFailed(error) {
  console.log(`Download failed: ${error}`);
}



function handleButtonClick(event) {
  let currentDate = getCurrentDate();

  let files = extractFileUrlsAndNames();

  for (let i = 0; i < files.length; i++) {
    // prefix files[i].filename with currentDate
    let prefixedFilename = currentDate + " " + files[i].filename;

    let dl = browser.downloads.download({
      url: files[i].url,
      filename: prefixedFilename,
      saveAs: (i == 0)   // raise a path chooser dialog for the first file only; all later files will (hopefully!) be saved to the same folder
    }).then(onStartedDownload, onFailed);  
  }
}




// add listener for the extension button
browser.browserAction.onClicked.addListener(handleButtonClick);