feat: Update converters for task and artifact events; add long running tools ids

PiperOrigin-RevId: 882591822

Author: google-genai-bot

a2a/src/main/java/com/google/adk/a2a/converters/PartConverter.java

@@ -78,13 +78,13 @@ public static Optional<TextPart> toTextPart(io.a2a.spec.Part<?> part) {
   }
 
   /** Convert an A2A JSON part into a Google GenAI part representation. */
-  public static Optional<com.google.genai.types.Part> toGenaiPart(io.a2a.spec.Part<?> a2aPart) {
+  public static com.google.genai.types.Part toGenaiPart(io.a2a.spec.Part<?> a2aPart) {
     if (a2aPart == null) {
-      return Optional.empty();
+      throw new IllegalArgumentException("A2A part cannot be null");
     }
 
     if (a2aPart instanceof TextPart textPart) {
-      return Optional.of(com.google.genai.types.Part.builder().text(textPart.getText()).build());
+      return com.google.genai.types.Part.builder().text(textPart.getText()).build();
     }
 
     if (a2aPart instanceof FilePart filePart) {
@@ -95,56 +95,41 @@ public static Optional<com.google.genai.types.Part> toGenaiPart(io.a2a.spec.Part
       return convertDataPartToGenAiPart(dataPart);
     }
 
-    logger.warn("Unsupported A2A part type: {}", a2aPart.getClass());
-    return Optional.empty();
+    throw new IllegalArgumentException("Unsupported A2A part type: " + a2aPart.getClass());
   }
 
   public static ImmutableList<com.google.genai.types.Part> toGenaiParts(
       List<io.a2a.spec.Part<?>> a2aParts) {
-    return a2aParts.stream()
-        .map(PartConverter::toGenaiPart)
-        .flatMap(Optional::stream)
-        .collect(toImmutableList());
+    return a2aParts.stream().map(PartConverter::toGenaiPart).collect(toImmutableList());
   }
 
-  private static Optional<com.google.genai.types.Part> convertFilePartToGenAiPart(
-      FilePart filePart) {
+  private static com.google.genai.types.Part convertFilePartToGenAiPart(FilePart filePart) {
     FileContent fileContent = filePart.getFile();
     if (fileContent instanceof FileWithUri fileWithUri) {
-      return Optional.of(
-          com.google.genai.types.Part.builder()
-              .fileData(
-                  FileData.builder()
-                      .fileUri(fileWithUri.uri())
-                      .mimeType(fileWithUri.mimeType())
-                      .build())
-              .build());
+      return com.google.genai.types.Part.builder()
+          .fileData(
+              FileData.builder()
+                  .fileUri(fileWithUri.uri())
+                  .mimeType(fileWithUri.mimeType())
+                  .build())
+          .build();
     }
 
     if (fileContent instanceof FileWithBytes fileWithBytes) {
       String bytesString = fileWithBytes.bytes();
       if (bytesString == null) {
-        logger.warn("FileWithBytes missing byte content");
-        return Optional.empty();
-      }
-      try {
-        byte[] decoded = Base64.getDecoder().decode(bytesString);
-        return Optional.of(
-            com.google.genai.types.Part.builder()
-                .inlineData(Blob.builder().data(decoded).mimeType(fileWithBytes.mimeType()).build())
-                .build());
-      } catch (IllegalArgumentException e) {
-        logger.warn("Failed to decode base64 file content", e);
-        return Optional.empty();
+        throw new GenAiFieldMissingException("FileWithBytes missing byte content");
       }
+      byte[] decoded = Base64.getDecoder().decode(bytesString);
+      return com.google.genai.types.Part.builder()
+          .inlineData(Blob.builder().data(decoded).mimeType(fileWithBytes.mimeType()).build())
+          .build();
     }
 
-    logger.warn("Unsupported FilePart content: {}", fileContent.getClass());
-    return Optional.empty();
+    throw new IllegalArgumentException("Unsupported FilePart content: " + fileContent.getClass());
   }
 
-  private static Optional<com.google.genai.types.Part> convertDataPartToGenAiPart(
-      DataPart dataPart) {
+  private static com.google.genai.types.Part convertDataPartToGenAiPart(DataPart dataPart) {
     Map<String, Object> data =
         Optional.ofNullable(dataPart.getData()).map(HashMap::new).orElseGet(HashMap::new);
     Map<String, Object> metadata =
@@ -154,67 +139,57 @@ private static Optional<com.google.genai.types.Part> convertDataPartToGenAiPart(
 
     if ((data.containsKey(NAME_KEY) && data.containsKey(ARGS_KEY))
         || metadataType.equals(A2ADataPartMetadataType.FUNCTION_CALL.getType())) {
-      String functionName = String.valueOf(data.getOrDefault(NAME_KEY, null));
-      String functionId = String.valueOf(data.getOrDefault(ID_KEY, null));
+      String functionName = String.valueOf(data.getOrDefault(NAME_KEY, ""));
+      String functionId = String.valueOf(data.getOrDefault(ID_KEY, ""));
       Map<String, Object> args = coerceToMap(data.get(ARGS_KEY));
-      return Optional.of(
-          com.google.genai.types.Part.builder()
-              .functionCall(
-                  FunctionCall.builder().name(functionName).id(functionId).args(args).build())
-              .build());
+      return com.google.genai.types.Part.builder()
+          .functionCall(FunctionCall.builder().name(functionName).id(functionId).args(args).build())
+          .build();
     }
 
     if ((data.containsKey(NAME_KEY) && data.containsKey(RESPONSE_KEY))
         || metadataType.equals(A2ADataPartMetadataType.FUNCTION_RESPONSE.getType())) {
       String functionName = String.valueOf(data.getOrDefault(NAME_KEY, ""));
       String functionId = String.valueOf(data.getOrDefault(ID_KEY, ""));
       Map<String, Object> response = coerceToMap(data.get(RESPONSE_KEY));
-      return Optional.of(
-          com.google.genai.types.Part.builder()
-              .functionResponse(
-                  FunctionResponse.builder()
-                      .name(functionName)
-                      .id(functionId)
-                      .response(response)
-                      .build())
-              .build());
+      return com.google.genai.types.Part.builder()
+          .functionResponse(
+              FunctionResponse.builder()
+                  .name(functionName)
+                  .id(functionId)
+                  .response(response)
+                  .build())
+          .build();
     }
 
     if ((data.containsKey(CODE_KEY) && data.containsKey(LANGUAGE_KEY))
         || metadataType.equals(A2ADataPartMetadataType.EXECUTABLE_CODE.getType())) {
       String code = String.valueOf(data.getOrDefault(CODE_KEY, ""));
       String language =
           String.valueOf(
-              data.getOrDefault(LANGUAGE_KEY, Language.Known.LANGUAGE_UNSPECIFIED.toString())
-                  .toString());
-      return Optional.of(
-          com.google.genai.types.Part.builder()
-              .executableCode(
-                  ExecutableCode.builder().code(code).language(new Language(language)).build())
-              .build());
+              data.getOrDefault(LANGUAGE_KEY, Language.Known.LANGUAGE_UNSPECIFIED.toString()));
+      return com.google.genai.types.Part.builder()
+          .executableCode(
+              ExecutableCode.builder().code(code).language(new Language(language)).build())
+          .build();
     }
 
     if ((data.containsKey(OUTCOME_KEY) && data.containsKey(OUTPUT_KEY))
         || metadataType.equals(A2ADataPartMetadataType.CODE_EXECUTION_RESULT.getType())) {
       String outcome =
           String.valueOf(data.getOrDefault(OUTCOME_KEY, Outcome.Known.OUTCOME_OK).toString());
       String output = String.valueOf(data.getOrDefault(OUTPUT_KEY, ""));
-      return Optional.of(
-          com.google.genai.types.Part.builder()
-              .codeExecutionResult(
-                  CodeExecutionResult.builder()
-                      .outcome(new Outcome(outcome))
-                      .output(output)
-                      .build())
-              .build());
+      return com.google.genai.types.Part.builder()
+          .codeExecutionResult(
+              CodeExecutionResult.builder().outcome(new Outcome(outcome)).output(output).build())
+          .build();
     }
 
     try {
       String json = objectMapper.writeValueAsString(data);
-      return Optional.of(com.google.genai.types.Part.builder().text(json).build());
+      return com.google.genai.types.Part.builder().text(json).build();
     } catch (JsonProcessingException e) {
-      logger.warn("Failed to serialize DataPart payload", e);
-      return Optional.empty();
+      throw new IllegalArgumentException("Failed to serialize DataPart payload", e);
     }
   }
 

a2a/src/main/java/com/google/adk/a2a/converters/ResponseConverter.java

@@ -16,6 +16,8 @@
 package com.google.adk.a2a.converters;
 
 import static com.google.common.collect.ImmutableList.toImmutableList;
+import static com.google.common.collect.ImmutableSet.toImmutableSet;
+import static com.google.common.collect.Streams.zip;
 
 import com.google.adk.agents.InvocationContext;
 import com.google.adk.events.Event;
@@ -29,13 +31,15 @@
 import io.a2a.client.TaskEvent;
 import io.a2a.client.TaskUpdateEvent;
 import io.a2a.spec.Artifact;
+import io.a2a.spec.DataPart;
 import io.a2a.spec.Message;
 import io.a2a.spec.Task;
 import io.a2a.spec.TaskArtifactUpdateEvent;
 import io.a2a.spec.TaskState;
 import io.a2a.spec.TaskStatusUpdateEvent;
 import java.time.Instant;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.UUID;
@@ -70,6 +74,14 @@ public static Optional<Event> clientEventToEvent(
     throw new IllegalArgumentException("Unsupported ClientEvent type: " + event.getClass());
   }
 
+  private static boolean isPartial(Map<String, Object> metadata) {
+    if (metadata == null) {
+      return false;
+    }
+    return Objects.equals(
+        metadata.getOrDefault(PartConverter.A2A_DATA_PART_METADATA_IS_PARTIAL_KEY, false), true);
+  }
+
   /**
    * Converts a A2A {@link TaskUpdateEvent} to an ADK {@link Event}, if applicable. Returns null if
    * the event is not a final update for TaskArtifactUpdateEvent or if the message is empty for
@@ -85,7 +97,14 @@ private static Optional<Event> handleTaskUpdate(
       boolean isAppend = Objects.equals(artifactEvent.isAppend(), true);
       boolean isLastChunk = Objects.equals(artifactEvent.isLastChunk(), true);
 
+      if (isLastChunk && isPartial(artifactEvent.getMetadata())) {
+        return Optional.empty();
+      }
+
       Event eventPart = artifactToEvent(artifactEvent.getArtifact(), context);
+      if (eventPart.content().flatMap(Content::parts).orElse(ImmutableList.of()).isEmpty()) {
+        return Optional.empty();
+      }
       eventPart.setPartial(isAppend || !isLastChunk);
       // append=true, lastChunk=false: emit as partial, update aggregation
       // append=false, lastChunk=false: emit as partial, reset aggregation
@@ -115,26 +134,21 @@ private static Optional<Event> handleTaskUpdate(
             .map(builder -> builder.turnComplete(true))
             .map(builder -> builder.partial(false))
             .map(Event.Builder::build);
-      } else {
-        return messageEvent;
       }
+      return messageEvent;
     }
     throw new IllegalArgumentException(
         "Unsupported TaskUpdateEvent type: " + updateEvent.getClass());
   }
 
   /** Converts an artifact to an ADK event. */
   public static Event artifactToEvent(Artifact artifact, InvocationContext invocationContext) {
-    Message message =
-        new Message.Builder().role(Message.Role.AGENT).parts(artifact.parts()).build();
-    return messageToEvent(message, invocationContext);
-  }
-
-  /** Converts an A2A message back to ADK events. */
-  public static Event messageToEvent(Message message, InvocationContext invocationContext) {
-    return remoteAgentEventBuilder(invocationContext)
-        .content(fromModelParts(PartConverter.toGenaiParts(message.getParts())))
-        .build();
+    Event.Builder eventBuilder = remoteAgentEventBuilder(invocationContext);
+    ImmutableList<Part> genaiParts = PartConverter.toGenaiParts(artifact.parts());
+    eventBuilder
+        .content(fromModelParts(genaiParts))
+        .longRunningToolIds(getLongRunningToolIds(artifact.parts(), genaiParts));
+    return eventBuilder.build();
   }
 
   /** Converts an A2A message for a failed task to ADK event filling in the error message. */
@@ -147,6 +161,13 @@ public static Event messageToFailedEvent(Message message, InvocationContext invo
     return builder.build();
   }
 
+  /** Converts an A2A message back to ADK events. */
+  public static Event messageToEvent(Message message, InvocationContext invocationContext) {
+    return remoteAgentEventBuilder(invocationContext)
+        .content(fromModelParts(PartConverter.toGenaiParts(message.getParts())))
+        .build();
+  }
+
   /**
    * Converts an A2A message back to ADK events. For streaming task in pending state it sets the
    * thought field to true, to mark them as thought updates.
@@ -168,25 +189,71 @@ public static Event messageToEvent(
    * If none of these are present, an empty event is returned.
    */
   public static Event taskToEvent(Task task, InvocationContext invocationContext) {
-    Message taskMessage = null;
-
-    if (!task.getArtifacts().isEmpty()) {
-      taskMessage =
-          new Message.Builder()
-              .messageId("")
-              .role(Message.Role.AGENT)
-              .parts(Iterables.getLast(task.getArtifacts()).parts())
-              .build();
-    } else if (task.getStatus().message() != null) {
-      taskMessage = task.getStatus().message();
-    } else if (!task.getHistory().isEmpty()) {
-      taskMessage = Iterables.getLast(task.getHistory());
+    ImmutableList.Builder<Part> genaiParts = ImmutableList.builder();
+    ImmutableSet.Builder<String> longRunningToolIds = ImmutableSet.builder();
+
+    for (Artifact artifact : task.getArtifacts()) {
+      ImmutableList<Part> converted = PartConverter.toGenaiParts(artifact.parts());
+      longRunningToolIds.addAll(getLongRunningToolIds(artifact.parts(), converted));
+      genaiParts.addAll(converted);
+    }
+
+    Event.Builder eventBuilder = remoteAgentEventBuilder(invocationContext);
+
+    if (task.getStatus().message() != null) {
+      ImmutableList<Part> msgParts =
+          PartConverter.toGenaiParts(task.getStatus().message().getParts());
+      longRunningToolIds.addAll(
+          getLongRunningToolIds(task.getStatus().message().getParts(), msgParts));
+      if (task.getStatus().state() == TaskState.FAILED
+          && msgParts.size() == 1
+          && msgParts.get(0).text().isPresent()) {
+        eventBuilder.errorMessage(msgParts.get(0).text().get());
+      } else {
+        genaiParts.addAll(msgParts);
+      }
     }
 
-    if (taskMessage != null) {
-      return messageToEvent(taskMessage, invocationContext);
+    ImmutableList<Part> finalParts = genaiParts.build();
+    boolean isFinal =
+        task.getStatus().state().isFinal() || task.getStatus().state() == TaskState.INPUT_REQUIRED;
+
+    if (finalParts.isEmpty() && !isFinal) {
+      return emptyEvent(invocationContext);
     }
-    return emptyEvent(invocationContext);
+    if (!finalParts.isEmpty()) {
+      eventBuilder.content(fromModelParts(finalParts));
+    }
+    if (task.getStatus().state() == TaskState.INPUT_REQUIRED) {
+      eventBuilder.longRunningToolIds(longRunningToolIds.build());
+    }
+    eventBuilder.turnComplete(isFinal);
+    return eventBuilder.build();
+  }
+
+  private static ImmutableSet<String> getLongRunningToolIds(
+      List<io.a2a.spec.Part<?>> parts, List<Part> convertedParts) {
+    return zip(
+            parts.stream(),
+            convertedParts.stream(),
+            (part, convertedPart) -> {
+              if (!(part instanceof DataPart dataPart)) {
+                return Optional.<String>empty();
+              }
+              Object isLongRunning =
+                  dataPart
+                      .getMetadata()
+                      .get(PartConverter.A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY);
+              if (!Objects.equals(isLongRunning, true)) {
+                return Optional.<String>empty();
+              }
+              if (convertedPart.functionCall().isEmpty()) {
+                return Optional.<String>empty();
+              }
+              return convertedPart.functionCall().get().id();
+            })
+        .flatMap(Optional::stream)
+        .collect(toImmutableSet());
   }
 
   private static Event emptyEvent(InvocationContext invocationContext) {