[plan] Support error handling strategy for built-in chat action.

api/src/main/java/org/apache/flink/agents/api/AgentBuilder.java

@@ -18,6 +18,7 @@
 
 package org.apache.flink.agents.api;
 
+import org.apache.flink.agents.api.agents.Agent;
 import org.apache.flink.streaming.api.datastream.DataStream;
 import org.apache.flink.table.api.Schema;
 import org.apache.flink.table.api.Table;

api/src/main/java/org/apache/flink/agents/api/Agent.java → api/src/main/java/org/apache/flink/agents/api/agents/Agent.java

@@ -16,8 +16,9 @@
  * limitations under the License.
  */
 
-package org.apache.flink.agents.api;
+package org.apache.flink.agents.api.agents;
 
+import org.apache.flink.agents.api.Event;
 import org.apache.flink.agents.api.resource.ResourceDescriptor;
 import org.apache.flink.agents.api.resource.ResourceType;
 import org.apache.flink.agents.api.resource.SerializableResource;
@@ -108,4 +109,22 @@ public Agent addResource(String name, ResourceType type, Object instance) {
         }
         return this;
     }
+
+    public enum ErrorHandlingStrategy {
+        FAIL("fail"),
+        RETRY("retry"),
+        IGNORE("ignore");
+
+        private final String value;
+
+        ErrorHandlingStrategy(String value) {
+            this.value = value;
+        }
+
+        public String getValue() {
+            return value;
+        }
+    }
+
+    public static String STRUCTURED_OUTPUT = "structured_output";
 }

api/src/main/java/org/apache/flink/agents/api/agents/ReActAgentConfigOptions.java → api/src/main/java/org/apache/flink/agents/api/agents/AgentExecutionOptions.java

@@ -20,12 +20,13 @@
 
 import org.apache.flink.agents.api.configuration.ConfigOption;
 
-/** Config Options for {@link ReActAgent}. */
-public class ReActAgentConfigOptions {
-    /** The option specifies the error handling strategy for react agent. */
-    public static final ConfigOption<ReActAgent.ErrorHandlingStrategy> ERROR_HANDLING_STRATEGY =
+public class AgentExecutionOptions {
+    public static final ConfigOption<Agent.ErrorHandlingStrategy> ERROR_HANDLING_STRATEGY =
             new ConfigOption<>(
                     "error-handling-strategy",
-                    ReActAgent.ErrorHandlingStrategy.class,
-                    ReActAgent.ErrorHandlingStrategy.FAIL);
+                    Agent.ErrorHandlingStrategy.class,
+                    Agent.ErrorHandlingStrategy.FAIL);
+
+    public static final ConfigOption<Integer> MAX_RETRIES =
+            new ConfigOption<>("max-retries", Integer.class, 0);
 }

api/src/main/java/org/apache/flink/agents/api/agents/OutputSchema.java

@@ -0,0 +1,134 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.agents.api.agents;
+
+import org.apache.flink.annotation.VisibleForTesting;
+import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
+import org.apache.flink.api.common.typeinfo.TypeInformation;
+import org.apache.flink.api.java.typeutils.RowTypeInfo;
+import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.core.JacksonException;
+import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.core.JsonGenerator;
+import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.core.JsonParser;
+import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.core.JsonProcessingException;
+import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.DeserializationContext;
+import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.JsonNode;
+import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.ObjectMapper;
+import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.SerializerProvider;
+import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.ser.std.StdSerializer;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Helper class for {@link RowTypeInfo} serialization.
+ *
+ * <p>Currently, only support row contains basic type.
+ */
+@VisibleForTesting
+@JsonSerialize(using = OutputSchema.OutputSchemaJsonSerializer.class)
+@JsonDeserialize(using = OutputSchema.OutputSchemaJsonDeserializer.class)
+public class OutputSchema {
+    private final RowTypeInfo schema;
+
+    public OutputSchema(RowTypeInfo schema) {
+        this.schema = schema;
+        for (TypeInformation<?> info : schema.getFieldTypes()) {
+            if (!info.isBasicType()) {
+                throw new IllegalArgumentException(
+                        "Currently, output schema only support row contains basic type.");
+            }
+        }
+    }
+
+    public RowTypeInfo getSchema() {
+        return schema;
+    }
+
+    public static class OutputSchemaJsonSerializer extends StdSerializer<OutputSchema> {
+
+        protected OutputSchemaJsonSerializer() {
+            super(OutputSchema.class);
+        }
+
+        @Override
+        public void serialize(
+                OutputSchema schema,
+                JsonGenerator jsonGenerator,
+                SerializerProvider serializerProvider)
+                throws IOException {
+            RowTypeInfo typeInfo = schema.getSchema();
+            jsonGenerator.writeStartObject();
+
+            jsonGenerator.writeFieldName("fieldNames");
+            jsonGenerator.writeStartArray();
+            for (String name : typeInfo.getFieldNames()) {
+                jsonGenerator.writeString(name);
+            }
+            jsonGenerator.writeEndArray();
+
+            // TODO: support type information which is not basic.
+            jsonGenerator.writeFieldName("types");
+            jsonGenerator.writeStartArray();
+            for (TypeInformation<?> info : typeInfo.getFieldTypes()) {
+                jsonGenerator.writeObject(info.getTypeClass());
+            }
+            jsonGenerator.writeEndArray();
+
+            jsonGenerator.writeEndObject();
+        }
+    }
+
+    public static class OutputSchemaJsonDeserializer extends StdDeserializer<OutputSchema> {
+        private static final ObjectMapper mapper = new ObjectMapper();
+
+        protected OutputSchemaJsonDeserializer() {
+            super(OutputSchema.class);
+        }
+
+        @Override
+        public OutputSchema deserialize(
+                JsonParser jsonParser, DeserializationContext deserializationContext)
+                throws IOException, JacksonException {
+            JsonNode node = jsonParser.getCodec().readTree(jsonParser);
+            List<String> fieldNames = new ArrayList<>();
+            node.get("fieldNames").forEach(fieldNameNode -> fieldNames.add(fieldNameNode.asText()));
+            List<TypeInformation<?>> types = new ArrayList<>();
+            node.get("types")
+                    .forEach(
+                            typeNode -> {
+                                try {
+                                    types.add(
+                                            BasicTypeInfo.getInfoFor(
+                                                    mapper.treeToValue(typeNode, Class.class)));
+                                } catch (JsonProcessingException e) {
+                                    throw new RuntimeException(e);
+                                }
+                            });
+
+            return new OutputSchema(
+                    new RowTypeInfo(
+                            types.toArray(new TypeInformation[0]),
+                            fieldNames.toArray(new String[0])));
+        }
+    }
+}