/// <summary>
/// Searches Index for
/// </summary>
/// <param name="query">What is searched for</param>
/// <param name="count">How many results gets back</param>
/// <param name="sortFunctionDesc">Sorts results with the same weight descending</param>
/// <returns></returns>
public IEnumerable <Result <T> > Search(string query, int count, Func <T, int> sortFunctionDescending = null)
{
var tokenizedQuery = _tokenizer.Tokenize(query);
List <ScoredSentence <T> > results = new List <ScoredSentence <T> >();
foreach (string queryToken in tokenizedQuery)
{
// tokeny, které odpovídají query
var filteredTokens = SortedTokens
.Where(t => t.Key.StartsWith(queryToken))
.Select(x => x.Value);
foreach (var token in filteredTokens)
{
var scoredSentences = ScoreToken(token, queryToken);
results.AddRange(scoredSentences);
}
}
var summedResults = results
.GroupBy(r => r.Sentence,
(sentence, result) => new ScoredSentence <T>(sentence, result.Sum(x => x.Score)))
.ToList();
// přidat score za nejdelší řetězec
foreach (ScoredSentence <T> result in summedResults)
{
result.Score += ScoreSentence(result.Sentence, tokenizedQuery);
}
if (sortFunctionDescending is null)
{
return(summedResults
.OrderByDescending(x => x.Score)
.Take(count)
.Select(x => new Result <T>()
{
Original = x.Sentence.Original,
Score = x.Score
}));
}
return(summedResults
.OrderByDescending(x => x.Score)
.ThenByDescending(x => sortFunctionDescending(x.Sentence.Original))
.Take(count)
.Select(x => new Result <T>()
{
Original = x.Sentence.Original,
Score = x.Score
}));
}
private void AddTokens(List <Token <T> > tokens)
{
for (int i = 0; i < tokens.Count(); i++)
{
if (SortedTokens.TryGetValue(tokens[i].Word, out Token <T> olderToken))
{
olderToken.MergeWith(tokens[i]);
}
else
{
SortedTokens.Add(tokens[i].Word, tokens[i]);
}
}
}
