let latestDownloadId;

/*
Callback from getFileIcon.
Initialize the displayed icon.
*/
function updateIconUrl(iconUrl) {
  let downloadIcon = document.querySelector("#icon");
  downloadIcon.setAttribute("src", iconUrl);
}

function onError(error) {
  console.log(`Error: ${error}`);
}

/*
If there was a download item,
- remember its ID as latestDownloadId
- initialize the displayed icon using getFileIcon
- initialize the displayed URL 
If there wasn't a download item, disable the "open" and "remove" buttons.
*/
function initializeLatestDownload(downloadItems) {
  let downloadUrl = document.querySelector("#url");
  if (downloadItems.length > 0) {
    latestDownloadId = downloadItems[0].id;
    let gettingIconUrl = browser.downloads.getFileIcon(latestDownloadId);
    gettingIconUrl.then(updateIconUrl, onError);
    downloadUrl.textContent = downloadItems[0].url;
    document.querySelector("#open").classList.remove("disabled");
    document.querySelector("#remove").classList.remove("disabled");
  } else {
    downloadUrl.textContent = "No downloaded items found."
    document.querySelector("#open").classList.add("disabled");
    document.querySelector("#remove").classList.add("disabled");
  }
}

/*
Search for the most recent download, and pass it to initializeLatestDownload()
*/
let searching = browser.downloads.search({
  limit: 1,
  orderBy: ["-startTime"]
});
searching.then(initializeLatestDownload);

/*
Open the item using the associated application.
*/
function openItem() {
  if (!document.querySelector("#open").classList.contains("disabled")) {
    browser.downloads.open(latestDownloadId);
  }
}

/*
Remove item from disk (removeFile) and from the download history (erase)
*/
function removeItem() {
  if (!document.querySelector("#remove").classList.contains("disabled")) {
    browser.downloads.removeFile(latestDownloadId);
    browser.downloads.erase({id: latestDownloadId});
    window.close();
  }
}

document.querySelector("#open").addEventListener("click", openItem);
document.querySelector("#remove").addEventListener("click", removeItem);