/*
 * Copyright 2024-2026 the original author or authors.
 *
 * Licensed 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
 *
 *      https://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 com.alibaba.cloud.ai.graph.serializer.plain_text.jackson;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.core.type.WritableTypeId;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.fasterxml.jackson.databind.ser.std.StdSerializer;
import org.springframework.ai.chat.messages.AssistantMessage;
import org.springframework.ai.zhipuai.ZhiPuAiAssistantMessage;

import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import static com.alibaba.cloud.ai.graph.serializer.plain_text.jackson.SerializationHelper.deserializeMetadata;
import static com.alibaba.cloud.ai.graph.serializer.plain_text.jackson.SerializationHelper.serializeMetadata;

public interface ZhiPuAIAssistantMessageHandler {

	enum Field {

		TEXT("text"), TOOL_CALLS("toolCalls"), REASONING_CONTENT("reasoningContent"), MEDIA("media");

		final String name;

		Field(String name) {
			this.name = name;
		}

	}

	class Serializer extends StdSerializer<ZhiPuAiAssistantMessage> {

		public Serializer() {
			super(ZhiPuAiAssistantMessage.class);
		}

		@Override
		public void serialize(ZhiPuAiAssistantMessage msg, JsonGenerator gen, SerializerProvider provider)
				throws IOException {
			gen.writeStartObject();
			serializeFields(msg, gen, provider);
			gen.writeEndObject();
		}

		@Override
		public void serializeWithType(ZhiPuAiAssistantMessage msg, JsonGenerator gen, SerializerProvider provider, TypeSerializer typeSer)
				throws IOException {
			WritableTypeId typeIdDef = typeSer.writeTypePrefix(gen, typeSer.typeId(msg, JsonToken.START_OBJECT));
			serializeFields(msg, gen, provider);
			typeSer.writeTypeSuffix(gen, typeIdDef);
		}

		private void serializeFields(ZhiPuAiAssistantMessage msg, JsonGenerator gen, SerializerProvider provider) throws IOException {
			String text = msg.getText();
			gen.writeStringField(Field.TEXT.name, text);

			List<AssistantMessage.ToolCall> toolCalls = msg.getToolCalls();

			gen.writeArrayFieldStart(Field.TOOL_CALLS.name);
			for (var toolCall : toolCalls) {
				gen.writeStartObject();
				gen.writeStringField("id", toolCall.id());
				gen.writeStringField("name", toolCall.name());
				gen.writeStringField("type", toolCall.type());
				gen.writeStringField("arguments", toolCall.arguments());
				gen.writeEndObject();
			}
			gen.writeEndArray();

			String reasoningContent = msg.getReasoningContent();

			if (reasoningContent != null) {
				gen.writeStringField(Field.REASONING_CONTENT.name, reasoningContent);
			}
			else {
				gen.writeNullField(Field.REASONING_CONTENT.name);
			}

			Map<String, Object> metadata = msg.getMetadata();
			serializeMetadata(gen, metadata);
		}

	}

	class Deserializer extends StdDeserializer<ZhiPuAiAssistantMessage> {

		protected Deserializer() {
			super(ZhiPuAiAssistantMessage.class);
		}

		@Override
		public ZhiPuAiAssistantMessage deserialize(JsonParser jsonParser, DeserializationContext ctx)
				throws IOException {
			var mapper = (ObjectMapper) jsonParser.getCodec();
			ObjectNode node = mapper.readTree(jsonParser);

			var textNode = node.get(Field.TEXT.name);
			var text = (textNode != null && !textNode.isNull()) ? textNode.asText() : "";
			var metadata = deserializeMetadata(mapper, node);
			var requestsNode = node.get(Field.TOOL_CALLS.name);

			var reasoningContentNode = node.get(Field.REASONING_CONTENT.name);
			var reasoningContent = (reasoningContentNode != null && !reasoningContentNode.isNull())
					? reasoningContentNode.asText() : null;

			var requests = new LinkedList<AssistantMessage.ToolCall>();

			if (requestsNode != null && !requestsNode.isNull() && !requestsNode.isEmpty()) {
				for (JsonNode requestNode : requestsNode) {
					var request = mapper.treeToValue(requestNode, AssistantMessage.ToolCall.class);
					requests.add(request);
				}
			}

			return new ZhiPuAiAssistantMessage.Builder()
					.content(text)
					.reasoningContent(reasoningContent)
					.properties(metadata)
					.toolCalls(requests)
					.build();
		}

	}

}
