[bug-fix] Handle BWC for bedrock converse API (#3173) (#3184)

* fix: bwc check for llm messages

Signed-off-by: Pavan Yekbote <[email protected]>

* fix: add bwc for llmquestion

Signed-off-by: Pavan Yekbote <[email protected]>

* test: adding ut for bwc

Signed-off-by: Pavan Yekbote <[email protected]>

* fix: test case which counts optional occurence

Signed-off-by: Pavan Yekbote <[email protected]>

---------

Signed-off-by: Pavan Yekbote <[email protected]>
(cherry picked from commit 24d2640)

Co-authored-by: Pavan Yekbote <[email protected]>

Author: opensearch-trigger-bot[bot]

search-processors/src/main/java/org/opensearch/searchpipelines/questionanswering/generative/ext/GenerativeQAParameters.java

@@ -24,13 +24,15 @@
 import java.util.List;
 import java.util.Objects;
 
+import org.opensearch.Version;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.core.xcontent.XContentParser;
+import org.opensearch.ml.common.CommonValue;
 import org.opensearch.searchpipelines.questionanswering.generative.llm.MessageBlock;
 
 import com.google.common.base.Preconditions;
@@ -86,6 +88,8 @@ public class GenerativeQAParameters implements Writeable, ToXContentObject {
 
     public static final int SIZE_NULL_VALUE = -1;
 
+    static final Version MINIMAL_SUPPORTED_VERSION_FOR_BEDROCK_CONVERSE_LLM_MESSAGES = CommonValue.VERSION_2_18_0;
+
     @Setter
     @Getter
     private String conversationId;
@@ -185,16 +189,27 @@ public GenerativeQAParameters(
     }
 
     public GenerativeQAParameters(StreamInput input) throws IOException {
+        Version version = input.getVersion();
         this.conversationId = input.readOptionalString();
         this.llmModel = input.readOptionalString();
-        this.llmQuestion = input.readOptionalString();
+
+        // this string was made optional in 2.18
+        if (version.onOrAfter(MINIMAL_SUPPORTED_VERSION_FOR_BEDROCK_CONVERSE_LLM_MESSAGES)) {
+            this.llmQuestion = input.readOptionalString();
+        } else {
+            this.llmQuestion = input.readString();
+        }
+
         this.systemPrompt = input.readOptionalString();
         this.userInstructions = input.readOptionalString();
         this.contextSize = input.readInt();
         this.interactionSize = input.readInt();
         this.timeout = input.readInt();
         this.llmResponseField = input.readOptionalString();
-        this.llmMessages.addAll(input.readList(MessageBlock::new));
+
+        if (version.onOrAfter(MINIMAL_SUPPORTED_VERSION_FOR_BEDROCK_CONVERSE_LLM_MESSAGES)) {
+            this.llmMessages.addAll(input.readList(MessageBlock::new));
+        }
     }
 
     @Override
@@ -246,16 +261,27 @@ public XContentBuilder toXContent(XContentBuilder xContentBuilder, Params params
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
+        Version version = out.getVersion();
         out.writeOptionalString(conversationId);
         out.writeOptionalString(llmModel);
-        out.writeOptionalString(llmQuestion);
+
+        // this string was made optional in 2.18
+        if (version.onOrAfter(MINIMAL_SUPPORTED_VERSION_FOR_BEDROCK_CONVERSE_LLM_MESSAGES)) {
+            out.writeOptionalString(llmQuestion);
+        } else {
+            out.writeString(llmQuestion);
+        }
+
         out.writeOptionalString(systemPrompt);
         out.writeOptionalString(userInstructions);
         out.writeInt(contextSize);
         out.writeInt(interactionSize);
         out.writeInt(timeout);
         out.writeOptionalString(llmResponseField);
-        out.writeList(llmMessages);
+
+        if (version.onOrAfter(MINIMAL_SUPPORTED_VERSION_FOR_BEDROCK_CONVERSE_LLM_MESSAGES)) {
+            out.writeList(llmMessages);
+        }
     }
 
     public static GenerativeQAParameters parse(XContentParser parser) throws IOException {

search-processors/src/test/java/org/opensearch/searchpipelines/questionanswering/generative/ext/GenerativeQAParamExtBuilderTests.java

@@ -21,6 +21,7 @@
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 import static org.opensearch.core.xcontent.ToXContent.EMPTY_PARAMS;
 
 import java.io.EOFException;
@@ -30,6 +31,7 @@
 import java.util.Map;
 
 import org.junit.Assert;
+import org.opensearch.Version;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentType;
@@ -119,9 +121,15 @@ public void testMiscMethods() throws IOException {
         assertNotEquals(builder1, builder2);
         assertNotEquals(builder1.hashCode(), builder2.hashCode());
 
-        StreamOutput so = mock(StreamOutput.class);
-        builder1.writeTo(so);
-        verify(so, times(6)).writeOptionalString(any());
+        StreamOutput so1 = mock(StreamOutput.class);
+        when(so1.getVersion()).thenReturn(GenerativeQAParameters.MINIMAL_SUPPORTED_VERSION_FOR_BEDROCK_CONVERSE_LLM_MESSAGES);
+        builder1.writeTo(so1);
+        verify(so1, times(6)).writeOptionalString(any());
+
+        StreamOutput so2 = mock(StreamOutput.class);
+        when(so2.getVersion()).thenReturn(Version.V_2_17_0);
+        builder1.writeTo(so2);
+        verify(so2, times(5)).writeOptionalString(any());
     }
 
     public void testParse() throws IOException {

search-processors/src/test/java/org/opensearch/searchpipelines/questionanswering/generative/ext/GenerativeQAParametersTests.java

@@ -26,7 +26,10 @@
 import java.util.List;
 import java.util.Map;
 
+import org.opensearch.Version;
 import org.opensearch.action.search.SearchRequest;
+import org.opensearch.common.io.stream.BytesStreamOutput;
+import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.xcontent.XContent;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -179,6 +182,48 @@ public void testWriteTo() throws IOException {
         assertTrue(timeout == intValues.get(2));
     }
 
+    public void testWriteToBwcBedrockConverse() throws IOException {
+        String conversationId = "a";
+        String llmModel = "b";
+        String llmQuestion = "c";
+        String systemPrompt = "s";
+        String userInstructions = "u";
+        int contextSize = 1;
+        int interactionSize = 2;
+        int timeout = 10;
+        String llmResponseField = "text";
+        GenerativeQAParameters expected = new GenerativeQAParameters(
+            conversationId,
+            llmModel,
+            llmQuestion,
+            systemPrompt,
+            userInstructions,
+            contextSize,
+            interactionSize,
+            timeout,
+            llmResponseField,
+            messageList
+        );
+
+        // Version.2_18_0 (MINIMAL_SUPPORTED_VERSION_FOR_BEDROCK_CONVERSE_LLM_MESSAGES)
+        BytesStreamOutput output = new BytesStreamOutput();
+        output.setVersion(GenerativeQAParameters.MINIMAL_SUPPORTED_VERSION_FOR_BEDROCK_CONVERSE_LLM_MESSAGES);
+        expected.writeTo(output);
+        StreamInput input = output.bytes().streamInput();
+        input.setVersion(GenerativeQAParameters.MINIMAL_SUPPORTED_VERSION_FOR_BEDROCK_CONVERSE_LLM_MESSAGES);
+        GenerativeQAParameters actual = new GenerativeQAParameters(input);
+        assertEquals(expected, actual);
+
+        // Version.2_17_0 (LlmMessages should be empty list)
+        output = new BytesStreamOutput();
+        output.setVersion(Version.V_2_17_0);
+        expected.writeTo(output);
+        input = output.bytes().streamInput();
+        input.setVersion(Version.V_2_17_0);
+        actual = new GenerativeQAParameters(input);
+        assertTrue(actual.getLlmMessages().isEmpty());
+    }
+
     public void testMisc() {
         String conversationId = "a";
         String llmModel = "b";