issue #957: fixes knn wrapper query generation

core/app/datasource/src/main/java/io/openk9/datasource/searcher/parser/impl/KnnQueryParser.java

@@ -25,6 +25,7 @@
 import jakarta.json.Json;
 import org.opensearch.client.json.jackson.JacksonJsonpMapper;
 import org.opensearch.client.opensearch._types.query_dsl.KnnQuery;
+import org.opensearch.client.opensearch._types.query_dsl.Query;
 import org.opensearch.index.query.QueryBuilders;
 
 import java.io.ByteArrayOutputStream;
@@ -55,7 +56,7 @@ public Uni<Void> apply(ParserContext parserContext) {
 
 		var tenantId = currentTenant.getTenant();
 
-		var knnQueryUnis = new ArrayList<Uni<KnnQuery>>();
+		var knnQueryUnis = new ArrayList<Uni<Query>>();
 
 		for (ParserSearchToken parserSearchToken : tokenTypeGroup) {
 
@@ -74,6 +75,7 @@ public Uni<Void> apply(ParserContext parserContext) {
 						.field("vector")
 						.vector(toVector(embeddedText))
 						.build()
+						.toQuery()
 					);
 
 				knnQueryUnis.add(knnQuery);
@@ -86,26 +88,32 @@ public Uni<Void> apply(ParserContext parserContext) {
 			.andCollectFailures()
 			.invoke(knnQueries -> {
 
-				for (KnnQuery knnQuery : knnQueries) {
+				for (Query knnQuery : knnQueries) {
 
-					try (var os = new ByteArrayOutputStream()) {
+					addsKnnQuery(parserContext, knnQuery);
+				}
 
-						var generator = Json.createGenerator(os);
+			})
+			.replaceWithVoid();
+	}
 
-						knnQuery.serialize(generator, new JacksonJsonpMapper());
+	protected static void addsKnnQuery(ParserContext parserContext, Query knnQuery) {
+		try (var os = new ByteArrayOutputStream()) {
 
-						var wrapperQueryBuilder = QueryBuilders.wrapperQuery(os.toByteArray());
+			var generator = Json.createGenerator(os);
 
-						parserContext.getMutableQuery().must(wrapperQueryBuilder);
+			knnQuery.serialize(generator, new JacksonJsonpMapper());
 
-					}
-					catch (IOException e) {
-						throw new RuntimeException(e);
-					}
-				}
+			generator.close();
 
-			})
-			.replaceWithVoid();
+			var wrapperQueryBuilder = QueryBuilders.wrapperQuery(os.toByteArray());
+
+			parserContext.getMutableQuery().must(wrapperQueryBuilder);
+
+		}
+		catch (IOException e) {
+			throw new RuntimeException(e);
+		}
 	}
 
 	private static float[] toVector(EmbeddingService.EmbeddedText embeddedText) {

core/app/datasource/src/test/java/io/openk9/datasource/searcher/parser/impl/KnnQueryParserTest.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2020-present SMC Treviso s.r.l. All rights reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package io.openk9.datasource.searcher.parser.impl;
+
+import com.jayway.jsonpath.JsonPath;
+import io.openk9.datasource.searcher.parser.ParserContext;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.opensearch.client.opensearch._types.query_dsl.KnnQuery;
+import org.opensearch.index.query.BoolQueryBuilder;
+
+import java.util.Base64;
+import java.util.List;
+
+class KnnQueryParserTest {
+
+	private static final int VECTOR_SIZE = 1800;
+	private static final int K_NEIGHBORS = 2;
+
+	@Test
+	void addsKnnQuery() {
+
+		var parserContext = new ParserContext();
+
+		var boolQueryBuilder = new BoolQueryBuilder();
+
+		parserContext.setMutableQuery(boolQueryBuilder);
+
+		var knnQueryBuilder = new KnnQuery.Builder()
+			.field("vector")
+			.k(K_NEIGHBORS)
+			.vector(randomVector(VECTOR_SIZE))
+			.build()
+			.toQuery();
+
+		KnnQueryParser.addsKnnQuery(parserContext, knnQueryBuilder);
+
+		var query = parserContext.getMutableQuery().toString();
+
+		String wrappedQuery = JsonPath.parse(query).read("$.bool.must[0].wrapper.query");
+
+		var wrappedKnnQuery = new String(Base64.getDecoder().decode(wrappedQuery));
+
+		var documentContext = JsonPath.parse(wrappedKnnQuery);
+
+		int k = documentContext.read("$.knn.vector.k");
+		List<Float> vector = documentContext.read("$.knn.vector.vector");
+
+		Assertions.assertEquals(K_NEIGHBORS, k);
+		Assertions.assertEquals(VECTOR_SIZE, vector.size());
+
+	}
+
+	private float[] randomVector(int size) {
+		var vector = new float[size];
+
+		for (int i = 0; i < size; i++) {
+
+			vector[i] = (float) Math.random();
+
+		}
+
+		return vector;
+	}
+
+}