public async Task <string> ClassifySentiment(string usersUtterance)
{
try
{
var data = new SentimentData()
{
SentimentText = usersUtterance
};
var blobResult = _blobService.DownloadModelAsync().Result;
if (blobResult != null)
{
var model = await PredictionModel.ReadAsync <SentimentData, SentimentPrediction>(blobResult);
var classification = model.Predict(data);
_logger.LogInfo($"Sentiment returned from model was: {classification.Sentiment}");
return($"{(classification.Sentiment ? "Positive" : "Negative")}");
}
return(null);
}
catch (Exception ex)
{
_logger.LogException(ex);
throw ex;
}
}
public async Task <Stream> DownloadModelAsync()
{
Stream stream = new MemoryStream();
try
{
_cache.TryGetValue("trainedModel", out stream);
if (stream != null)
{
return(stream);
}
else
{
stream = new MemoryStream();
await blockBlob.DownloadToStreamAsync(target : stream);
_cache.Set("trainedModel", stream);
}
return(stream);
}
catch (Exception ex)
{
_logger.LogException(ex);
return(null);
}
}
public async Task <IActionResult> Get([FromQuery(Name = "query")] string query)
{
try
{
if (string.IsNullOrEmpty(query))
{
return(BadRequest("'query' url parameter is missing."));
}
var classifedUtterance = await _classifyService.ClassifySentiment(query);
if (!string.IsNullOrEmpty(classifedUtterance))
{
return(Json($"Sentiment: {classifedUtterance}"));
}
return(Json($"Error: Could not receive response from Blob Storage."));
}
catch (Exception ex)
{
_logger.LogException(ex);
return(Json("Exception occurred, please try again later."));
}
}