/*
 * Copyright 2025 Google. This software is provided as-is, without warranty or representation for any use or purpose. 
 * Your use of it is subject to your agreement with Google.
 */

package com.example.mapper.conversation;

import com.google.cloud.dialogflow.cx.v3.QueryResult;
import com.google.cloud.dialogflow.cx.v3.ResponseMessage;
import com.google.cloud.dialogflow.cx.v3.DetectIntentResponse;
import com.example.dto.dialogflow.base.DetectIntentResponseDTO;
import com.example.dto.dialogflow.conversation.QueryResultDTO;
import com.example.util.ProtobufUtil;

import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.stream.Collectors;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

/**
 * Spring component responsible for mapping a Dialogflow CX API response
 * (`DetectIntentResponse`) to a simplified custom DTO (`DetectIntentResponseDTO`).
 * It extracts and consolidates the fulfillment text, and converts Protobuf
 * session parameters into standard Java objects, providing a clean and
 * decoupled interface for consuming Dialogflow results.
 */
@Component
public class DialogflowResponseMapper {

    private static final Logger logger = LoggerFactory.getLogger(DialogflowResponseMapper.class);

    public DetectIntentResponseDTO mapFromDialogflowResponse(DetectIntentResponse response, String sessionId) {

        logger.info("Starting mapping of Dialogflow DetectIntentResponse for session: {}", sessionId);

        String responseId = response.getResponseId();
        QueryResult dfQueryResult = response.getQueryResult();
        logger.debug("Extracted QueryResult object for session: {}", sessionId);

        StringBuilder responseTextBuilder = new StringBuilder();
        if (dfQueryResult.getResponseMessagesList().isEmpty()) {
            logger.debug("No response messages found in QueryResult for session: {}", sessionId);
        }

        for (ResponseMessage message : dfQueryResult.getResponseMessagesList()) {
            if (message.hasText()) {
                logger.debug("Processing text response message for session: {}", sessionId);
                for (String text : message.getText().getTextList()) {
                    if (responseTextBuilder.length() > 0) {
                        responseTextBuilder.append(" ");
                    }
                    responseTextBuilder.append(text);
                    logger.debug("Appended text segment: '{}' to fulfillment text for session: {}", text, sessionId);
                }
            } else {
                logger.debug("Skipping non-text response message type: {} for session: {}", message.getMessageCase(), sessionId);
            }
        }

        String responseText = responseTextBuilder.toString().trim();

        Map<String, Object> parameters = new LinkedHashMap<>(); // Inicializamos vacío para evitar NPEs después

        if (dfQueryResult.hasParameters()) {
            // Usamos un forEach en lugar de Collectors.toMap para tener control total sobre nulos
            dfQueryResult.getParameters().getFieldsMap().forEach((key, value) -> {
                try {
                    Object convertedValue = ProtobufUtil.convertProtobufValueToJavaObject(value);
                    
                    // Si el valor convertido es nulo, decidimos qué hacer. 
                    // Lo mejor es poner un String vacío o ignorarlo para que no explote tu lógica.
                    if (convertedValue != null) {
                        parameters.put(key, convertedValue);
                    } else {
                        logger.warn("El parámetro '{}' devolvió un valor nulo al convertir. Se ignorará.", key);
                        // Opcional: parameters.put(key, ""); 
                    }
                } catch (Exception e) {
                    logger.error("Error convirtiendo el parámetro '{}' de Protobuf a Java: {}", key, e.getMessage());
                }
            });

            logger.debug("Extracted parameters: {} for session: {}", parameters, sessionId);
        } else {
            logger.debug("No parameters found in QueryResult for session: {}. Using empty map.", sessionId);
        }

        QueryResultDTO ourQueryResult = new QueryResultDTO(responseText, parameters);
        logger.debug("Internal QueryResult DTO created for session: {}. Details: {}", sessionId, ourQueryResult);

        DetectIntentResponseDTO finalResponse = new DetectIntentResponseDTO(responseId, ourQueryResult);
        logger.info("Finished mapping DialogflowDetectIntentResponse for session: {}. Full response ID: {}", sessionId, responseId);
        return finalResponse;
    }
    
}