/*-
 * #%L
 * Smile CDR - CDR
 * %%
 * Copyright (C) 2016 - 2025 Smile CDR, Inc.
 * %%
 * All rights reserved.
 * #L%
 */
package ca.cdr.api.util;

import ca.cdr.api.model.json.TransactionLogStepJson;
import ca.cdr.api.pub.hl7v2.model.MappingMessage;
import ca.uhn.fhir.rest.api.server.RequestDetails;
import ca.uhn.fhir.rest.server.servlet.ServletRequestDetails;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.commons.lang3.Validate;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * NOTE: this utility is using vanilla Jackson - FHIR resources can not be serialized.
 */
public class TransactionLogRequestDetailsUtil {
        public static final String STEPS_LIST_KEY = TransactionLogRequestDetailsUtil.class.getName() + "_STEPS_LIST";
        public static final String REQUEST_SUBTYPE_KEY =
                        TransactionLogRequestDetailsUtil.class.getName() + "_REQUEST_SUBTYPE_KEY";
        private static final String MESSAGES_LIST_KEY = TransactionLogRequestDetailsUtil.class.getName() + "_MESSAGES_LIST";
        private static final String ADDITIONAL_JSON_MAP_KEY =
                        TransactionLogRequestDetailsUtil.class.getName() + "_ADDITIONAL_JSON_MAP";

        private static final ObjectMapper ourObjectMapper = new ObjectMapper();

        private TransactionLogRequestDetailsUtil() {}

        public static void addMessageToRequest(RequestDetails theDetails, MappingMessage theMessage) {
                Validate.notNull(theDetails, "theDetails must not be null");
                Validate.notNull(theMessage, "theMessage must not be null");
                @SuppressWarnings("unchecked")
                List<MappingMessage> messages =
                                (List<MappingMessage>) theDetails.getUserData().get(MESSAGES_LIST_KEY);
                if (messages == null) {
                        messages = new ArrayList<>();
                        theDetails.getUserData().put(MESSAGES_LIST_KEY, messages);
                }
                messages.add(theMessage);
        }

        public static List<MappingMessage> getMessagesOnRequest(RequestDetails theDetails) {
                @SuppressWarnings("unchecked")
                List<MappingMessage> messages =
                                (List<MappingMessage>) theDetails.getUserData().get(MESSAGES_LIST_KEY);
                if (messages == null) {
                        return List.of();
                }
                return Collections.unmodifiableList(messages);
        }

        public static List<TransactionLogStepJson> getTransactionLogStepsFromRequest(RequestDetails theRequestDetails) {
                @SuppressWarnings("unchecked")
                List<TransactionLogStepJson> steps =
                                (List<TransactionLogStepJson>) theRequestDetails.getUserData().get(STEPS_LIST_KEY);
                if (steps == null) {
                        return List.of();
                }
                return Collections.unmodifiableList(steps);
        }

        /**
         * Adds a transaction log step to the attribute which holds the list of steps for the provided request.
         * @param theRequest the request
         * @param theStep the transaction log step to add
         */
        public static void addTransactionLogStepForRequest(RequestDetails theRequest, TransactionLogStepJson theStep) {
                Validate.notNull(theRequest, "theRequest must not be null");
                Validate.notNull(theStep, "theStep must not be null");
                @SuppressWarnings("unchecked")
                List<TransactionLogStepJson> steps =
                                (List<TransactionLogStepJson>) theRequest.getUserData().get(STEPS_LIST_KEY);
                if (steps == null) {
                        steps = new ArrayList<>();
                        theRequest.getUserData().put(STEPS_LIST_KEY, steps);
                }
                steps.add(theStep);
        }

        /**
         * NOTE: this method is using vanilla Jackson - FHIR resources can not be serialized.
         *
         * Utility method to add key/value pairs to a transactionLog.  The provided value needs to be serializable
         * with Jackson since pairs are accumulated and subsequently formatted in an inline json string.
         * IllegalArgumentException is thrown if <code>theValue</code> is not Json serializable with Jackson or <code>null</code>.
         *      The additional log properties will be tallied and rendered as inline json in the transactionLogEventJson:
         *{
         *              "id": 2,
         *      "initialTimestamp": "2023-08-29T14:00:30.096-04:00",
         *              "type": "FHIR_REQUEST",
         *              "subType": "FHIR_CREATE",
         *              "outcome": "SUCCESS",
         *              ...
         *              "requestId": "r1bW96uhRAn2z8iU",
         *              "additionalJson": { "diseases": [ "Tuberculosis", "Polio", "Malaria", "Dengue fever"], "clinic": "Acme Ouest" },
         *              ...
         *              "userFamilyName": "GenericUser",
         *              "userGivenName": "Admin"
         *              }
         *
         * @param theRequestDetails The request details where the pairs will be stored
         * @param theKey The key for referencing to theObject.  Keys are transformed into json properties when serializing a pair.
         * @param theValue The value needing storage.  Values are transformed into json values when serializing a pair.
         *
         */
        public static void addAdditionalJsonProperty(RequestDetails theRequestDetails, String theKey, Object theValue) {
                Validate.notNull(theRequestDetails, "theDetails must not be null");
                Validate.notNull(theKey, "theKey must not be null");
                Validate.notNull(theValue, "theValue must not be null");

                try {
                        // ensure that the value can be serialized to JSON
                        ourObjectMapper.writeValueAsString(theValue);
                } catch (JsonProcessingException e) {
                        throw new IllegalArgumentException(
                                        String.format(
                                                        "Unable to add pair with key %s to the additional Json property as the provided value object could not be parsed.",
                                                        theKey),
                                        e);
                }
                @SuppressWarnings("unchecked")
                Map<String, Object> additionalJsonPropertiesMap =
                                (Map<String, Object>) theRequestDetails.getUserData().get(ADDITIONAL_JSON_MAP_KEY);
                if (additionalJsonPropertiesMap == null) {
                        additionalJsonPropertiesMap = new HashMap<>();
                        theRequestDetails.getUserData().put(ADDITIONAL_JSON_MAP_KEY, additionalJsonPropertiesMap);
                }
                additionalJsonPropertiesMap.put(theKey, theValue);
        }

        public static Map<String, Object> getAdditionalJsonPropertiesMap(RequestDetails theRequestDetails) {
                Validate.notNull(theRequestDetails, "theRequestDetails must not be null");
                @SuppressWarnings("unchecked")
                Map<String, Object> additionalJsonPropertiesMap =
                                (Map<String, Object>) theRequestDetails.getUserData().get(ADDITIONAL_JSON_MAP_KEY);
                if (additionalJsonPropertiesMap == null) {
                        return Map.of();
                }
                return additionalJsonPropertiesMap;
        }

        public static boolean hasTransactionLogSteps(ServletRequestDetails theRequestDetails) {
                return theRequestDetails.getUserData().containsKey(STEPS_LIST_KEY);
        }
}