/// <summary>
/// Initializes a new instance of the <see cref="StringKeywordSuggestion"/> class.
/// </summary>
/// <param name="keywordValue">Sets value of keyword</param>
/// <param name="sourceId">Id of the source that is creating this suggestion</param>
/// <param name="sourceName">Optional id of the source. If not provided the name will be </param>
public StringKeywordSuggestion(string keywordValue, Guid sourceId, string sourceName = "")
{
if (keywordValue.Trim().Equals(string.Empty))
{
throw new ArgumentException("KeywordValue should not be an empty string");
}
if (sourceId == null)
{
throw new ArgumentNullException("Source id is not set");
}
if (keywordValue.Equals(string.Empty))
{
throw new ArgumentException();
}
this.objectValue = new SimpleStringObject(keywordValue);
this.sourceId = sourceId;
this.sourceName = sourceName.Equals(string.Empty) ? this.sourceId.ToString() : this.sourceName = sourceName;
this.rankValue = 1;
this.relevance = -1;
}
/// <summary>
/// Suggests description instances from the defined in Suggester sources based on one or more semantic objects
/// </summary>
/// <param name="semanticObjects">RDF based concrete semantic object</param>
/// <param name="sourceFilter">if Null all sources are used, if set only those set are processed</param>
/// <returns>Returns collection of suggested description objects (such as keywords, RDF statements, etc.)</returns>
public List<ISuggestionInstance> GetSuggestions(ISemanticObject[] semanticObjects, Guid[] sourceFilter = null)
{
Dictionary<string, Tuple<ISuggestionInstance, double>> CombinedCollection = new Dictionary<string, Tuple<ISuggestionInstance, double>>();
double maxRelevanceSum = 0;
double minRelevanceValue = double.MaxValue;
const string combinedSourceName = "Multiple sources";
Guid combinedGuid = Guid.NewGuid();
foreach (var nextSource in this.sources)
{
if (sourceFilter == null || sourceFilter.Contains(nextSource.Guid))
{
foreach (var nextResult in nextSource.GetSuggestions(semanticObjects))
{
double combinedrelevance;
if (CombinedCollection.ContainsKey(nextResult.GetTextValue()))
{
var oldvalue = CombinedCollection[nextResult.GetTextValue()];
combinedrelevance = oldvalue.Item2 + nextResult.Relevance;
// HACK - think how this should be when RDF suggestions sources implemented. Should we flatter them like this or do something else.
var combinedResult = new StringKeywordSuggestion(nextResult.GetTextValue(), combinedGuid, combinedSourceName);
nextResult.Rank = nextResult.Rank + oldvalue.Item1.Rank;
CombinedCollection[nextResult.GetTextValue()] = new Tuple<ISuggestionInstance, double>(combinedResult, combinedrelevance);
}
else
{
combinedrelevance = nextResult.Relevance;
CombinedCollection.Add(nextResult.GetTextValue(), new Tuple<ISuggestionInstance, double>(nextResult, combinedrelevance));
}
if (combinedrelevance > maxRelevanceSum)
{
maxRelevanceSum = combinedrelevance;
}
if (combinedrelevance < minRelevanceValue)
{
minRelevanceValue = combinedrelevance;
}
}
}
}
// now normalize relevance
var readyList = new List<ISuggestionInstance>();
foreach (var nextSuggestion in CombinedCollection)
{
// map 0...max to 0..100;
double newrelevance = (maxRelevanceSum * nextSuggestion.Value.Item2 == 0) ? 0 : 100 / maxRelevanceSum * nextSuggestion.Value.Item2;
var nextsuggestion = nextSuggestion.Value.Item1;
nextsuggestion.Relevance = newrelevance;
readyList.Add(nextsuggestion);
}
readyList.Sort(delegate (ISuggestionInstance x, ISuggestionInstance y)
{
return y.Relevance.CompareTo(x.Relevance); // descending sort
});
return readyList;
}
