text: /*
  Default settings. If there is nothing in storage, use these values.
  */
  var defaultSettings = {
    since: "hour",
    dataTypes: ["history", "downloads"]
  };
  
  /*
  Generic error logger.
  */
  function onError(e) {
    console.error(e);
  }
  
  /*
  On startup, check whether we have stored settings.
  If we don't, then store the default settings.
  */
  function checkStoredSettings(storedSettings) {
    if (!storedSettings.since || !storedSettings.dataTypes) {
      browser.storage.local.set(defaultSettings);
    }
  }
  
  const gettingStoredSettings = browser.storage.local.get();
  gettingStoredSettings.then(checkStoredSettings, onError);
  
  /*
  Forget browsing data, according to the settings passed in as storedSettings
  or, if this is empty, according to the default settings.
  */
  function forget(storedSettings) {
  
    /*
    Convert from a string to a time.
    The string is one of: "hour", "day", "week", "forever".
    The time is given in milliseconds since the epoch.
    */
    function getSince(selectedSince) {
      if (selectedSince === "forever") {
        return 0;
      }
  
      const times = {
        hour: () => { return 1000 * 60 * 60 },
        day: () => { return 1000 * 60 * 60 * 24 },
        week: () => { return 1000 * 60 * 60 * 24 * 7}
      }
  
      const sinceMilliseconds = times[selectedSince].call();
      return Date.now() - sinceMilliseconds;
    }
  
    /*
    Convert from an array of strings, representing data types,
    to an object suitable for passing into browsingData.remove().
    */
    function getTypes(selectedTypes) {
      let dataTypes = {};
      for (let item of selectedTypes) {
        dataTypes[item] = true;
      }
      return dataTypes;
    }
  
    const since = getSince(storedSettings.since);
    const dataTypes = getTypes(storedSettings.dataTypes);
  
    function notify() {
      let dataTypesString = Object.keys(dataTypes).join(", ");
      let sinceString = new Date(since).toLocaleString();
      browser.notifications.create({
        "type": "basic",
        "title": "Removed browsing data",
        "message": `Removed ${dataTypesString}\nsince ${sinceString}`
      });
    }
  
    browser.browsingData.remove({since}, dataTypes).then(notify);
  }
  
  /*
  On click, fetch stored settings and forget browsing data.
  */
  browser.browserAction.onClicked.addListener(() => {
    const gettingStoredSettings = browser.storage.local.get();
    gettingStoredSettings.then(forget, onError);
  });
  