/// <summary>
/// Merges multiple ResultObjects of different categories to a single list of ContentObjects.
/// The merge is based on a set of weights.
/// </summary>
/// <param name="results">An array of different ResultObjects for several categories</param>
/// <param name="ratio">An array with weights for the different categories in the results array</param>
/// <returns>
/// A list of ContentObjects where the content's value is the weighted score per category. The list is sorted in
/// descending order (the higher the value, the earlier in the list)
/// </returns>
public List <ContentObject> Merge(ResultObject[] results, CategoryRatio ratio)
{
// Attetion! No sanity checks: Must be different result.categories, ratios must sum up to 1.
var totalResults = new List <ContentObject>();
var scores = Prepare(results);
while (scores.Count > 0)
{
var list = Pop(scores);
while (list.Count > 0)
{
var needle = Pop(list);
var lonely = true;
foreach (var haystack in scores)
{
var size = haystack.Count;
for (var i = 0; i < size; i++)
{
if (needle.Equals(haystack[i]))
{
var t = haystack[i];
totalResults.Add(MergeWeighted(needle.Key, new[] { needle.Score, t.Score },
new[] { ratio.GetRatio(needle.Category), ratio.GetRatio(t.Category) }));
haystack.Remove(t);
size--;
lonely = false;
}
}
}
if (lonely)
{
var weightedScore = needle.Score * ratio.GetRatio(needle.Category);
totalResults.Add(new ContentObject(needle.Key, weightedScore.ToString()));
}
}
}
totalResults.Sort((a, b) => - 1 * a.CompareTo(b));
return(totalResults);
}
