InitialCode Commit

2025-09-07 19:06:43 +02:00
parent 887948bb02
commit d29e25992b
183 changed files with 82537 additions and 0 deletions
@@ -0,0 +1,96 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Primitives;
+using MTG_CollectionVerwaltung.Data.MTGCollection;
+
+namespace MTG_CollectionVerwaltung.Helpers
+{
+    public class CardSearcher
+    {
+        public static List<CardPrinting>? SearchCards(
+        MTGContext db, string query, int maxResults = 100)
+        {
+            // Schritt 1: FTS MATCH für schnelle Eingrenzung
+            List<CardPrinting>? candidates = GetNames(db, query + "*", maxResults * 20);
+
+            if (candidates == null) return null;
+
+            if (candidates.Count == 0 && query.Length >= 3)
+            {
+                List<string> tokens = Grammize(query);
+                foreach(string token in tokens)
+                {
+                    candidates.AddRange(GetNames(db, token, maxResults * 20));
+                    candidates.DistinctBy(c=> c.Id);
+                }
+            }
+
+            if (candidates.Count == 0) return null;
+
+            // Schritt 3: Levenshtein im Speicher anwenden
+            List<(CardPrinting card, int distance)> ranked = RankResults(db, candidates, query, maxResults);
+
+            if (ranked[0].distance == 0)
+            {
+                return ranked.Where(c => c.distance == 0).Select(x=>x.card).ToList();
+            }
+
+            return ranked.Select(x=>x.card).ToList();
+        }
+
+        private static List<string> Grammize(string query)
+        {
+            List<string> results = new List<string>();
+            query = query.ToLower();
+            query = new string(query.Where(char.IsLetterOrDigit).ToArray());
+            if (query.Length <= 3)
+            {
+                string[] substrings = [query.Substring(0, query.Length - 1), query.Substring(1, query.Length - 1)];
+                for (char c = 'a'; c <= 'z'; c++)
+                {
+                    results.Add(substrings[0] + c);
+                    results.Add(c + substrings[1]);
+                }
+                return results;
+            }
+
+            for (int i = 0; i < query.Length - 2; i++)
+            {
+                results.Add(query.Substring(i, 3));
+            }
+
+            return results;
+        }
+
+        private static List<CardPrinting> GetNames(MTGContext db, string query, int maxResults)
+        {
+            return db.CardPrintings
+                .FromSqlRaw(@"SELECT cp.*
+                        FROM CardPrintings cp
+                        JOIN CardPrintingsFTS fts
+                        ON cp.Id = fts.rowid
+                        WHERE fts.rowid IN (
+                            SELECT MIN(rowid)
+                            FROM CardPrintingsFTS
+                            WHERE Name MATCH {0}
+                            GROUP BY Name
+                        )
+                ", query)
+                .Take(maxResults)
+                .Include(cp => cp.Card)
+                .ToList();
+        }
+
+        private static List<(CardPrinting card, int distance)> RankResults(MTGContext db, List<CardPrinting> candidates,string query, int maxResults)
+        {
+            return candidates
+                .DistinctBy(c => c.Id)
+                .Select(c => (card: c, dist: MTGContext.LevenshteinMinWordDistanceByLength(c.Name.ToLower(), query.ToLower())))
+                .Where(x => x.dist <= 3)
+                .DistinctBy(c => c.card.Name)
+                .OrderBy(x => x.dist)
+                .Take(maxResults)
+                .ToList();
+        }
+
+    }
+}