/// <summary>
/// Queries openHistorian for annotations in a time-range (e.g., Alarms).
/// </summary>
/// <param name="request">Annotation request.</param>
/// <param name="cancellationToken">Cancellation token.</param>
/// <returns>Queried annotations from data source.</returns>
public async Task<List<AnnotationResponse>> Annotations(AnnotationRequest request, CancellationToken cancellationToken)
{
bool useFilterExpression;
AnnotationType type = request.ParseQueryType(out useFilterExpression);
Dictionary<string, DataRow> definitions = request.ParseSourceDefinitions(type, Metadata, useFilterExpression);
List<TimeSeriesValues> annotationData = await Query(request.ExtractQueryRequest(definitions.Keys, MaximumAnnotationsPerRequest), cancellationToken);
List<AnnotationResponse> responses = new List<AnnotationResponse>();
foreach (TimeSeriesValues values in annotationData)
{
string target = values.target;
DataRow definition = definitions[target];
foreach (double[] datapoint in values.datapoints)
{
if (type.IsApplicable(datapoint))
{
AnnotationResponse response = new AnnotationResponse
{
annotation = request.annotation,
time = datapoint[TimeSeriesValues.Time]
};
type.PopulateResponse(response, target, definition, datapoint, Metadata);
responses.Add(response);
}
}
}
return responses;
}
