/// <summary>
/// Retrieve an image (i.e. download an image to your computer)
/// </summary>
/// <param name="imageId">The id of the image to download</param>
/// <param name="filename">The full path and filename to save the downloaded image as</param>
/// <param name="progressEventHandler">The event handler to call with progress updates</param>
/// <remarks>Requires the API Key to have LEGACY access enabled</remarks>
public async Task ImageRetrieveAsync(int imageId, string filename, EventHandler <ImageRetrieveProgressChangedEventArgs> progressEventHandler)
{
var ImageDetails = await this.ImageDetailsAsync(imageId);
using (NoKeepAlivesWebClient WC = new NoKeepAlivesWebClient())
{
WC.Proxy = null;
if (progressEventHandler != null)
{
WC.DownloadProgressChanged += (s, e) =>
{
progressEventHandler(s, new ImageRetrieveProgressChangedEventArgs(e.BytesReceived, e.TotalBytesToReceive > 0 ? e.TotalBytesToReceive : ImageDetails.size));
};
}
Uri RetrieveImageUrl = new Uri($"{BASE_URL_LEGACY}?category=image&action=retrieve&image_id={imageId}&api_id={_APIId}&api_key={_APIKey}");
await WC.DownloadFileTaskAsync(RetrieveImageUrl, filename);
// TODOX Final progressEventHandler() call would be good, but how to know how many bytes were received/expected?
// Without final call program displays - Downloaded 28,180,193,280 of 28,182,839,296 bytes (99.99 %)...
// Check for JSON indicating a failure
try
{
if (File.Exists(filename))
{
FileInfo FI = new FileInfo(filename);
if (FI.Length < 1024)
{
string FileContents = File.ReadAllText(filename);
BaseResponseModel BRM = (new JavaScriptSerializer()).Deserialize <BaseResponseModel>(FileContents);
if (BRM.success != "yes")
{
throw new LNDException(BRM.error);
}
}
}
}
catch (LNDException)
{
// Re-throw the LNDException so the caller knows the retrieve failed
throw;
}
catch
{
// If it happened to be a REALLLLY small image (<1024 bytes), then DeserializeObject() will throw
// an exception. The File.ReadAllText() could also throw an exception if the file happened to be
// locked by another process right after the download finished.
// We're going to ignore these types of exceptions, with the assumption that the image downloaded
// successfully
}
}
}
private async Task <T> RequestAsync <T>(string category, string action, BaseRequestModel requestModel)
{
using (NoKeepAlivesWebClient WC = new NoKeepAlivesWebClient())
{
WC.Proxy = null;
var Serializer = new JavaScriptSerializer();
requestModel.api_id = _APIId;
requestModel.api_partialkey = _APIKey.Substring(0, 64);
string ModelData = Serializer.Serialize(requestModel);
int Nonce = (int)(DateTime.UtcNow - new DateTime(1970, 1, 1)).TotalSeconds; // https://dzone.com/articles/get-unix-epoch-time-one-line-c
string Signature = hash_hmac_sha512($"{category}/{action}/|{ModelData}|{Nonce.ToString()}", _APIKey);
NameValueCollection RequestData = new NameValueCollection()
{
{ "req", ModelData },
{ "signature", Signature },
{ "nonce", Nonce.ToString() }
};
Uri RequestUrl = new Uri(DYNAMIC_URL.Replace("{CATEGORY}", category).Replace("{ACTION}", action));
string ResponseText = Encoding.UTF8.GetString(await WC.UploadValuesTaskAsync(RequestUrl, "POST", RequestData));
//if (Debugger.IsAttached)
//{
// string LogFilename = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "lndapi.log");
// File.AppendAllText(LogFilename, $"{category}/{action}{Environment.NewLine}{ModelData}{Environment.NewLine}{ResponseText}{Environment.NewLine}{Environment.NewLine}");
//}
BaseResponseModel BRM = Serializer.Deserialize <BaseResponseModel>(ResponseText);
if (BRM.success == "yes")
{
return(Serializer.Deserialize <T>(ResponseText));
}
else
{
throw new LNDException(BRM.error);
}
}
}
