console.log("background.js started");

var baseUrl = "";

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 onSuccess(result) {
  console.log(`background.js: onSuccess(): Promise resolved with result '${JSON.stringify(result)}'`); 
}

function onFailure(error) {
  console.log(`background.js: onFailure(): Promise rejected with error '${error}'`);
}

// actually download an attached  file
async function downloadFile(url, filename, saveAs=false) {
  console.log(`background.js: downloadFile(): url is '${url}' and filename is '${filename}'`);
  return browser.downloads.download({
    url: new URL(url, baseUrl).toString(),
    filename: filename,
    saveAs: saveAs  // raise a path chooser dialog if true
  });
}

// sequentially initiate download for each attached file
async function downloadAllFiles(date, urlsAndFilenames) {
  for (let i = 0; i < urlsAndFilenames.length; i++) {
    // prefix filename
    let prefixedFilename = date + " " + urlsAndFilenames[i].filename;
    console.log(`background.js: downloadAllFiles(): i is ${i}`);
    await downloadFile(urlsAndFilenames[i].url, prefixedFilename, true).then(onSuccess, onFailure);
  }
}

// page action handler
function handlePageactionClick(tab) {
  console.log("background.js: handlePageactionClick(): sending message");
  
  // get base url
  browser.tabs.query({currentWindow: true, active: true})
  .then(tabs => {
    console.log(`background.js: handlePageactionClick(): tab query returned ${JSON.stringify(tabs)}`);
    baseUrl = tabs[0].url;
  })
  
  // send message to content script which will trigger said content script 
  browser.tabs.sendMessage(tab.id, "pageAction was clicked")
  .then(message => {
    console.log(`background.js: received a response from contentscript.js with content ${JSON.stringify(message.urlsAndFilenames)} | ${JSON.stringify(message.date)}`);
    downloadAllFiles(message.date, message.urlsAndFilenames);
  })
  .catch(error =>
    console.error(`background.js: handlePageactionClick(): The following error occured while handling a page action: ${error}`)
  )
}

// add listener for the extension button
browser.pageAction.onClicked.addListener(handlePageactionClick);