/// <summary>
/// Transfer the downloaded song to the given <see cref="SongTarget"/>s.
/// </summary>
/// <param name="targets"></param>
/// <param name="downloadContainer"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
/// <exception cref="OperationCanceledException"></exception>
protected async Task <TargetResult[]> TransferToTargets(IEnumerable <SongTarget> targets, DownloadContainer downloadContainer, CancellationToken cancellationToken)
{
List <TargetResult> completedTargets = new List <TargetResult>(_targets.Length);
foreach (SongTarget?target in targets)
{
cancellationToken.ThrowIfCancellationRequested();
TargetResult result = await target.TransferAsync(Song, downloadContainer.GetResultStream(), cancellationToken).ConfigureAwait(false);
completedTargets.Add(result);
_stageIndex++;
ReportProgress(JobProgress.CreateTargetCompletion(CurrentProgress, result));
}
return(completedTargets.ToArray());
}
/// <summary>
/// Starts the job.
/// </summary>
/// <param name="cancellationToken"></param>
/// <returns></returns>
public async Task RunAsync(CancellationToken cancellationToken)
{
JobState = JobState.Running;
if (CancellationToken.CanBeCanceled)
{
CancellationTokenSource?cts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, CancellationToken);
cancellationToken = cts.Token;
cts.Dispose();
cts = null;
}
JobStage = JobStage.Downloading;
Exception? exception = null;
bool canceled = false;
EventHandler?handler = JobStarted;
handler?.Invoke(this, null);
DownloadContainer? downloadContainer = null;
List <TargetResult> completedTargets = new List <TargetResult>(_targets.Length);
List <SongTarget> pendingTargets = new List <SongTarget>(_targets.Length);
foreach (SongTarget?target in _targets)
{
SongState songState = await target.CheckSongExistsAsync(Song).ConfigureAwait(false);
if (songState != SongState.Wanted)
{
completedTargets.Add(new TargetResult(target, songState, true, null));
}
else
{
pendingTargets.Add(target);
}
}
try
{
cancellationToken.ThrowIfCancellationRequested();
if (string.IsNullOrEmpty(Song.Key))
{
SongInfoResponse?result = await WebUtils.SongInfoManager.GetSongByHashAsync(Song.Hash, cancellationToken).ConfigureAwait(false);
if (result.Success)
{
Song.Key = result.Song?.Key;
}
}
if (pendingTargets.Count > 0)
{
_downloadJob.JobProgressChanged += _downloadJob_JobProgressChanged;
DownloadResult = await _downloadJob.RunAsync(cancellationToken).ConfigureAwait(false);
downloadContainer = DownloadResult.DownloadContainer;
if (DownloadResult.Exception != null)
{
throw DownloadResult.Exception;
}
_stageIndex = 1;
ReportProgress(JobProgress.CreateDownloadCompletion(CurrentProgress, DownloadResult));
JobStage = JobStage.TransferringToTargets;
foreach (TargetResult?targetResult in completedTargets)
{
_stageIndex++;
ReportProgress(JobProgress.CreateTargetCompletion(CurrentProgress, targetResult));
}
completedTargets.AddRange(await TransferToTargets(pendingTargets, downloadContainer, cancellationToken).ConfigureAwait(false));
}
else
{
DownloadResult = new DownloadResult(null, DownloadResultStatus.Skipped, 0);
_stageIndex = 1;
_downloadJob_JobProgressChanged(this, new DownloadJobProgressChangedEventArgs(DownloadJobStatus.Finished));
JobStage = JobStage.TransferringToTargets;
foreach (TargetResult?targetResult in completedTargets)
{
_stageIndex++;
ReportProgress(JobProgress.CreateTargetCompletion(CurrentProgress, targetResult));
}
}
TargetResult[] failedTargets = completedTargets.Where(t => !t.Success).ToArray();
if (failedTargets.Length > 0)
{
Exception?firstException = failedTargets.FirstOrDefault(t => t.Exception != null)?.Exception;
if (firstException != null)
{
throw firstException;
}
}
TargetResults = completedTargets.ToArray();
}
catch (OperationCanceledException ex)
{
if (TargetResults == null && completedTargets.Count > 0)
{
TargetResults = completedTargets.ToArray();
}
else
{
TargetResults = Array.Empty <TargetResult>();
}
canceled = true;
exception = ex;
ReportProgress(JobProgress.CreateFromFault(JobProgressType.Cancellation, JobStage, CurrentProgress));
JobState = JobState.Cancelled;
}
catch (Exception ex)
{
if (TargetResults == null && completedTargets.Count > 0)
{
TargetResults = completedTargets.ToArray();
}
else
{
TargetResults = Array.Empty <TargetResult>();
}
exception = ex;
JobState = JobState.Error;
ReportProgress(JobProgress.CreateFromFault(JobProgressType.Error, JobStage, CurrentProgress));
}
finally
{
JobStage = JobStage.Finishing;
try
{
downloadContainer?.Dispose();
}
catch { }
if (DownloadResult == null)
{
// TODO: What was this for?
}
FinishJob(canceled, exception);
JobFinishedAsyncCallback?asyncCallback = JobFinishedAsyncCallback;
if (asyncCallback != null)
{
await asyncCallback(Result).ConfigureAwait(false);
}
}
}