using Google.Play.AssetDelivery;
// Loads the AssetBundle from disk, downloading the asset pack containing it if necessary.
PlayAssetBundleRequest bundleRequest = PlayAssetDelivery.RetrieveAssetBundleAsync(asset-bundle-name);

// Download progress of request, between 0.0f and 1.0f. The value will always be
// 1.0 for assets delivered as install-time.
// NOTE: A value of 1.0 will only signify the download is complete. It will still need to be loaded.
float progress = bundleRequest.DownloadProgress;
// Returns true if:
//   * it had either completed the download, installing, and loading of the AssetBundle,
//   * OR if it has encountered an error.
bool done = bundleRequest.IsDone;
// Returns status of retrieval request.
AssetDeliveryStatus status = bundleRequest.Status;
switch(status) {
    case AssetDeliveryStatus.Pending:
        // Asset pack download is pending - N/A for install-time assets.
    case AssetDeliveryStatus.Retrieving:
        // Asset pack is being downloaded and transferred to app storage.
        // N/A for install-time assets.
    case AssetDeliveryStatus.Available:
        // Asset pack is downloaded on disk but NOT loaded into memory.
        // For PlayAssetPackRequest(), this indicates that the request is complete.
    case AssetDeliveryStatus.Loading:
        // Asset pack is being loaded.
    case AssetDeliveryStatus.Loaded:
        // Asset pack has finished loading, assets can now be loaded.
        // For PlayAssetBundleRequest(), this indicates that the request is complete.
    case AssetDeliveryStatus.Failed:
        // Asset pack retrieval has failed.
    case AssetDeliveryStatus.WaitingForWifi:
        // Asset pack retrieval paused until either the device connects via Wi-Fi,
        // or the user accepts the PlayAssetDelivery.ShowCellularDataConfirmation dialog.
    default:
        break;
}

if(bundleRequest.Status == AssetDeliveryStatus.WaitingForWifi) {
    var userConfirmationOperation = PlayAssetDelivery.ShowCellularDataConfirmation();
    yield return userConfirmationOperation;
    switch(userConfirmationOperation.GetResult()) {
        case ConfirmationDialogResult.Unknown:
            // userConfirmationOperation finished with an error. Something went
            // wrong when displaying the prompt to the user, and they weren't
            // able to interact with the dialog. In this case, we recommend
            // developers wait for Wi-Fi before attempting to download again.
            // You can get more info by calling GetError() on the operation.
        case ConfirmationDialogResult.Accepted:
            // User accepted the confirmation dialog - download will start
            // automatically (no action needed).
        case ConfirmationDialogResult.Declined:
            // User canceled or declined the dialog. Await Wi-Fi connection, or
            // re-prompt the user.
        default:
            break;
    }
}

// Will only attempt if the status is Pending, Retrieving, or Available - otherwise
// it will be a no-op.
bundleRequest.AttemptCancel();
// Check to see if the request was successful by checking if the error code is Canceled.
if(bundleRequest.Error == AssetDeliveryErrorCode.Canceled) {
    // Request was successfully canceled.
}

private IEnumerator LoadAssetBundleCoroutine(string assetBundleName) {
    PlayAssetBundleRequest bundleRequest =
        PlayAssetDelivery.RetrieveAssetBundleAsync(assetBundleName);
    while (!bundleRequest.IsDone) {
        if(bundleRequest.Status == AssetDeliveryStatus.WaitingForWifi) {
            var userConfirmationOperation = PlayAssetDelivery.ShowCellularDataConfirmation();
            // Wait for confirmation dialog action.
            yield return userConfirmationOperation;
            if((userConfirmationOperation.Error != AssetDeliveryErrorCode.NoError) ||
               (userConfirmationOperation.GetResult() != ConfirmationDialogResult.Accepted)) {
                // The user did not accept the confirmation - handle as needed.
            }
            // Wait for Wi-Fi connection OR confirmation dialog acceptance before moving on.
            yield return new WaitUntil(() => bundleRequest.Status != AssetDeliveryStatus.WaitingForWifi);
        }
        // Use bundleRequest.DownloadProgress to track download progress.
        // Use bundleRequest.Status to track the status of request.
        yield return null;
    }
    if (bundleRequest.Error != AssetDeliveryErrorCode.NoError) {
        // There was an error retrieving the bundle. For error codes NetworkError
        // and InsufficientStorage, you may prompt the user to check their
        // connection settings or check their storage space, respectively, then
        // try again.
        yield return null;
    }
    // Request was successful. Retrieve AssetBundle from request.AssetBundle.
    AssetBundle assetBundle = bundleRequest.AssetBundle;

public IEnumerator GetDownloadSize() {
   PlayAsyncOperation<long> getSizeOperation =
   PlayAssetDelivery.GetDownloadSize(assetPackName);
   yield return getSizeOperation;
   if(operation.Error != AssetDeliveryErrorCode.NoError) {
       // Error while retrieving download size.
    } else {
        // Download size is given in bytes.
        long downloadSize = operation.GetResult();
    }
}