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}'`);
}

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
  });
}

async function downloadAllFiles(urlsAndFilenames) {
  console.log(`background.js: downloadAllFiles(): started with ${JSON.stringify(urlsAndFilenames)}`);
  const currentDate = getCurrentDate();

  
  for (let i = 0; i < urlsAndFilenames.length; i++) {
    // prefix filename
    let prefixedFilename = currentDate + " " + urlsAndFilenames[i].filename;
    console.log(`background.js: downloadAllFiles(): i is ${i}`);
    if ( i == 0 ) {
      await downloadFile(urlsAndFilenames[i].url, prefixedFilename, true).then(onSuccess, onFailure);
    } else {
      downloadFile(urlsAndFilenames[i].url, prefixedFilename, true).then(onSuccess, onFailure);
    }
  }
}

function handlePageactionClick(tab, onClickData) {
  console.log("background.js: handlePageactionClick(): executing content script");
  
  // 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;
    }
  )
  
  // execute content script
  browser.scripting.executeScript(
    {
      files: [ "/contentscript.js" ],
      target: 
      {
        tabId: tab.id,
        allFrames: false
      }
    }
  )
  .then(results => {
    console.log(`background.js: handlePageactionClick(): content script execution successful with results '${JSON.stringify(results)}'`);
    results.forEach(r => downloadAllFiles(r.result));
  })
  .catch(error => 
    console.error(`background.js: handlePageactionClick(): The following error occured while executing a content script: ${error}`)
  )
}

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