BE: Issue#1332 Sort based on prefix offsets

api/src/main/java/io/kafbat/ui/config/ClustersProperties.java

@@ -237,6 +237,7 @@ public static class CacheProperties {
   public static class NgramProperties {
     int ngramMin = 1;
     int ngramMax = 4;
+    boolean distanceScore = true;
   }
 
   @Data
@@ -245,10 +246,10 @@ public static class NgramProperties {
   public static class ClusterFtsProperties {
     boolean enabled = true;
     boolean defaultEnabled = false;
-    NgramProperties schemas = new NgramProperties(1, 4);
-    NgramProperties consumers = new NgramProperties(1, 4);
-    NgramProperties connect = new NgramProperties(1, 4);
-    NgramProperties acl = new NgramProperties(1, 4);
+    NgramProperties schemas = new NgramProperties(1, 4, true);
+    NgramProperties consumers = new NgramProperties(1, 4, true);
+    NgramProperties connect = new NgramProperties(1, 4, true);
+    NgramProperties acl = new NgramProperties(1, 4, true);
 
     public boolean use(Boolean request) {
       if (enabled) {

api/src/main/java/io/kafbat/ui/controller/KafkaConnectController.java

@@ -23,6 +23,7 @@
 import io.kafbat.ui.service.mcp.McpTool;
 import java.util.Comparator;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import javax.validation.Valid;
 import lombok.RequiredArgsConstructor;
@@ -137,15 +138,18 @@ public Mono<ResponseEntity<Flux<FullConnectorInfoDTO>>> getAllConnectors(
         .operationName("getAllConnectors")
         .build();
 
+    var maybeComparator = Optional.ofNullable(orderBy).map(this::getConnectorsComparator);
+
     var comparator = sortOrder == null || sortOrder.equals(SortOrderDTO.ASC)
-        ? getConnectorsComparator(orderBy)
-        : getConnectorsComparator(orderBy).reversed();
+        ? maybeComparator
+        : maybeComparator.map(Comparator::reversed);
+
+    Flux<FullConnectorInfoDTO> connectors = kafkaConnectService.getAllConnectors(getCluster(clusterName), search, fts)
+        .filterWhen(dto -> accessControlService.isConnectAccessible(dto.getConnect(), clusterName));
 
-    Flux<FullConnectorInfoDTO> job = kafkaConnectService.getAllConnectors(getCluster(clusterName), search, fts)
-        .filterWhen(dto -> accessControlService.isConnectAccessible(dto.getConnect(), clusterName))
-        .sort(comparator);
+    Flux<FullConnectorInfoDTO> sorted = comparator.map(connectors::sort).orElse(connectors);
 
-    return Mono.just(ResponseEntity.ok(job))
+    return Mono.just(ResponseEntity.ok(sorted))
         .doOnEach(sig -> audit(context, sig));
   }
 
@@ -280,9 +284,7 @@ private Comparator<FullConnectorInfoDTO> getConnectorsComparator(ConnectorColumn
         FullConnectorInfoDTO::getName,
         Comparator.nullsFirst(Comparator.naturalOrder())
     );
-    if (orderBy == null) {
-      return defaultComparator;
-    }
+
     return switch (orderBy) {
       case CONNECT -> Comparator.comparing(
           FullConnectorInfoDTO::getConnect,

api/src/main/java/io/kafbat/ui/controller/SchemasController.java

@@ -25,6 +25,7 @@
 import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import javax.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
@@ -244,10 +245,10 @@ public Mono<ResponseEntity<SchemaSubjectsResponseDTO>> getSchemas(String cluster
 
           List<String> subjectsToRetrieve;
           boolean paginate = true;
-          var schemaComparator = getComparatorForSchema(orderBy);
-          final Comparator<SubjectWithCompatibilityLevel> comparator =
+          var schemaComparator = Optional.ofNullable(orderBy).map(this::getComparatorForSchema);
+          final Optional<Comparator<SubjectWithCompatibilityLevel>> comparator =
               sortOrder == null || !sortOrder.equals(SortOrderDTO.DESC)
-                  ? schemaComparator : schemaComparator.reversed();
+                  ? schemaComparator : schemaComparator.map(Comparator::reversed);
           if (orderBy == null || SchemaColumnsToSortDTO.SUBJECT.equals(orderBy)) {
             if (SortOrderDTO.DESC.equals(sortOrder)) {
               filteredSubjects.sort(Comparator.nullsFirst(Comparator.reverseOrder()));
@@ -274,11 +275,13 @@ public Mono<ResponseEntity<SchemaSubjectsResponseDTO>> getSchemas(String cluster
 
   private List<SubjectWithCompatibilityLevel> paginateSchemas(
       List<SubjectWithCompatibilityLevel> subjects,
-      Comparator<SubjectWithCompatibilityLevel> comparator,
+      Optional<Comparator<SubjectWithCompatibilityLevel>> comparator,
       boolean paginate,
       int pageSize,
       int subjectToSkip) {
-    subjects.sort(comparator);
+
+    comparator.ifPresent(subjects::sort);
+
     if (paginate) {
       return subjects.subList(subjectToSkip, Math.min(subjectToSkip + pageSize, subjects.size()));
     } else {

api/src/main/java/io/kafbat/ui/service/index/AclBindingNgramFilter.java

@@ -11,7 +11,7 @@ public class AclBindingNgramFilter extends NgramFilter<AclBinding> {
   private final List<Tuple2<List<String>, AclBinding>> bindings;
 
   public AclBindingNgramFilter(Collection<AclBinding> bindings) {
-    this(bindings, true, new ClustersProperties.NgramProperties(1, 4));
+    this(bindings, true, new ClustersProperties.NgramProperties(1, 4, true));
   }
 
   public AclBindingNgramFilter(

api/src/main/java/io/kafbat/ui/service/index/ConsumerGroupFilter.java

@@ -11,7 +11,7 @@ public class ConsumerGroupFilter extends NgramFilter<ConsumerGroupListing> {
   private final List<Tuple2<List<String>, ConsumerGroupListing>> groups;
 
   public ConsumerGroupFilter(Collection<ConsumerGroupListing> groups) {
-    this(groups, true, new ClustersProperties.NgramProperties(1, 4));
+    this(groups, true, new ClustersProperties.NgramProperties(1, 4, true));
   }
 
   public ConsumerGroupFilter(

api/src/main/java/io/kafbat/ui/service/index/KafkaConnectNgramFilter.java

@@ -11,7 +11,7 @@ public class KafkaConnectNgramFilter extends NgramFilter<FullConnectorInfoDTO> {
   private final List<Tuple2<List<String>, FullConnectorInfoDTO>> connectors;
 
   public KafkaConnectNgramFilter(Collection<FullConnectorInfoDTO> connectors) {
-    this(connectors, true, new ClustersProperties.NgramProperties(1, 4));
+    this(connectors, true, new ClustersProperties.NgramProperties(1, 4, true));
   }
 
   public KafkaConnectNgramFilter(

api/src/main/java/io/kafbat/ui/service/index/LuceneTopicsIndex.java

@@ -2,6 +2,9 @@
 
 import io.kafbat.ui.model.InternalTopic;
 import io.kafbat.ui.model.InternalTopicConfig;
+import io.kafbat.ui.service.index.lucene.IndexedTextField;
+import io.kafbat.ui.service.index.lucene.NameDistanceScoringFunction;
+import io.kafbat.ui.service.index.lucene.ShortWordAnalyzer;
 import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.util.ArrayList;
@@ -18,11 +21,11 @@
 import org.apache.lucene.document.IntPoint;
 import org.apache.lucene.document.LongPoint;
 import org.apache.lucene.document.StringField;
-import org.apache.lucene.document.TextField;
 import org.apache.lucene.index.DirectoryReader;
 import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.IndexWriterConfig;
 import org.apache.lucene.index.Term;
+import org.apache.lucene.queries.function.FunctionScoreQuery;
 import org.apache.lucene.queryparser.classic.ParseException;
 import org.apache.lucene.queryparser.classic.QueryParser;
 import org.apache.lucene.search.BooleanClause;
@@ -59,11 +62,13 @@ public LuceneTopicsIndex(List<InternalTopic> topics) throws IOException {
 
   private Directory build(List<InternalTopic> topics) {
     Directory directory = new ByteBuffersDirectory();
+
     try (IndexWriter directoryWriter = new IndexWriter(directory, new IndexWriterConfig(this.analyzer))) {
       for (InternalTopic topic : topics) {
         Document doc = new Document();
+
         doc.add(new StringField(FIELD_NAME_RAW, topic.getName(), Field.Store.YES));
-        doc.add(new TextField(FIELD_NAME, topic.getName(), Field.Store.NO));
+        doc.add(new IndexedTextField(FIELD_NAME, topic.getName(), Field.Store.YES));
         doc.add(new IntPoint(FIELD_PARTITIONS, topic.getPartitionCount()));
         doc.add(new IntPoint(FIELD_REPLICATION, topic.getReplicationFactor()));
         doc.add(new LongPoint(FIELD_SIZE, topic.getSegmentSize()));
@@ -117,9 +122,9 @@ public List<InternalTopic> find(String search, Boolean showInternal,
     closeLock.readLock().lock();
     try {
 
-      QueryParser queryParser = new PrefixQueryParser(FIELD_NAME, this.analyzer);
+      PrefixQueryParser queryParser = new PrefixQueryParser(FIELD_NAME, this.analyzer);
       queryParser.setDefaultOperator(QueryParser.Operator.AND);
-      Query nameQuery = queryParser.parse(search);;
+      Query nameQuery = queryParser.parse(search);
 
       Query internalFilter = new TermQuery(new Term(FIELD_INTERNAL, "true"));
 
@@ -129,6 +134,12 @@ public List<InternalTopic> find(String search, Boolean showInternal,
         queryBuilder.add(internalFilter, BooleanClause.Occur.MUST_NOT);
       }
 
+      BooleanQuery combined = queryBuilder.build();
+      Query wrapped = new FunctionScoreQuery(
+          combined,
+          new NameDistanceScoringFunction(FIELD_NAME, queryParser.getPrefixes())
+      );
+
       List<SortField> sortFields = new ArrayList<>();
       sortFields.add(SortField.FIELD_SCORE);
       if (!sortField.equals(FIELD_NAME)) {
@@ -137,7 +148,7 @@ public List<InternalTopic> find(String search, Boolean showInternal,
 
       Sort sort = new Sort(sortFields.toArray(new SortField[0]));
 
-      TopDocs result = this.indexSearcher.search(queryBuilder.build(), count != null ? count : this.maxSize, sort);
+      TopDocs result = this.indexSearcher.search(wrapped, count != null ? count : this.maxSize, sort);
 
       List<String> topics = new ArrayList<>();
       for (ScoreDoc scoreDoc : result.scoreDocs) {

api/src/main/java/io/kafbat/ui/service/index/NgramFilter.java

@@ -10,6 +10,9 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.NavigableMap;
+import java.util.TreeMap;
+import java.util.TreeSet;
 import java.util.stream.Stream;
 import lombok.SneakyThrows;
 import lombok.extern.slf4j.Slf4j;
@@ -22,9 +25,11 @@
 public abstract class NgramFilter<T> {
   private final Analyzer analyzer;
   private final boolean enabled;
+  private final boolean distanceScore;
 
   public NgramFilter(ClustersProperties.NgramProperties properties, boolean enabled) {
     this.enabled = enabled;
+    this.distanceScore = properties.isDistanceScore();
     this.analyzer = new ShortWordNGramAnalyzer(properties.getNgramMin(), properties.getNgramMax(), false);
   }
 
@@ -52,15 +57,25 @@ public List<T> find(String search, Comparator<T> comparator) {
     try {
       List<SearchResult<T>> result = new ArrayList<>();
       List<String> queryTokens = tokenizeString(analyzer, search);
-      Map<String, Integer> queryFreq = termFreq(queryTokens);
+      Map<String, Integer> queryFreq = Map.of();
+
+      if (!distanceScore) {
+        queryFreq = termFreq(queryTokens);
+      }
 
       for (Tuple2<List<String>, T> item : getItems()) {
         for (String field : item.getT1()) {
           List<String> itemTokens = tokenizeString(analyzer, field);
           HashSet<String> itemTokensSet = new HashSet<>(itemTokens);
           if (itemTokensSet.containsAll(queryTokens)) {
-            double score = cosineSimilarity(queryFreq, itemTokens);
+            double score;
+            if (distanceScore) {
+              score = distanceSimilarity(queryTokens, itemTokens);
+            } else {
+              score = cosineSimilarity(queryFreq, itemTokens);
+            }
             result.add(new SearchResult<>(item.getT2(), score));
+            break;
           }
         }
       }
@@ -77,6 +92,22 @@ public List<T> find(String search, Comparator<T> comparator) {
     }
   }
 
+  private double distanceSimilarity(List<String> queryTokens, List<String> itemTokens) {
+    int smallest = Integer.MAX_VALUE;
+    for (String queryToken : queryTokens) {
+      int i = itemTokens.indexOf(queryToken);
+      if (i >= 0) {
+        smallest = Math.min(smallest, i);
+      }
+    }
+
+    if (smallest == Integer.MAX_VALUE) {
+      return 1.0;
+    } else {
+      return 1.0 / (1.0 + smallest);
+    }
+  }
+
   private List<T> list(Stream<T> stream, Comparator<T> comparator) {
     if (comparator != null) {
       return stream.sorted(comparator).toList();

api/src/main/java/io/kafbat/ui/service/index/PrefixQueryParser.java

@@ -3,7 +3,9 @@
 import static org.apache.lucene.search.BoostAttribute.DEFAULT_BOOST;
 
 import io.kafbat.ui.service.index.TopicsIndex.FieldType;
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.document.IntPoint;
@@ -14,10 +16,11 @@
 import org.apache.lucene.search.PrefixQuery;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.TermQuery;
-import org.apache.lucene.search.TermRangeQuery;
 
 public class PrefixQueryParser extends QueryParser {
 
+  private final List<String> prefixes = new ArrayList<>();
+
   public PrefixQueryParser(String field, Analyzer analyzer) {
     super(field, analyzer);
   }
@@ -60,7 +63,13 @@ protected Query newTermQuery(Term term, float boost) {
         .orElse(FieldType.STRING);
 
     Query query =  switch (fieldType) {
-      case STRING -> new PrefixQuery(term);
+      case STRING -> {
+        if (Objects.equals(term.field(), field)) {
+          prefixes.add(term.text());
+        }
+
+        yield new PrefixQuery(term);
+      }
       case INT -> IntPoint.newExactQuery(term.field(), Integer.parseInt(term.text()));
       case LONG -> LongPoint.newExactQuery(term.field(), Long.parseLong(term.text()));
       case BOOLEAN -> new TermQuery(term);
@@ -72,4 +81,7 @@ protected Query newTermQuery(Term term, float boost) {
     return new BoostQuery(query, boost);
   }
 
+  public List<String> getPrefixes() {
+    return prefixes;
+  }
 }

api/src/main/java/io/kafbat/ui/service/index/SchemasFilter.java

@@ -16,7 +16,7 @@ public SchemasFilter(Collection<String> subjects, boolean enabled, ClustersPrope
 
   @Override
   public List<String> find(String search) {
-    return super.find(search, String::compareTo);
+    return super.find(search, null);
   }
 
   @Override