package org.gcube.portlets.user.geoportaldataentry.server;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.List;

import org.gcube.application.geoportalcommon.shared.geoportal.config.GcubeProfileDV;
import org.gcube.portlets.user.geoportaldataentry.shared.GeoNaFormDataObject;
import org.gcube.portlets.widgets.mpformbuilder.shared.GenericDatasetBean;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The Class FormDataObjectToJSON.
 *
 * @author Francesco Mangiacrapa at ISTI-CNR francesco.mangiacrapa@isti.cnr.it
 * 
 * Mar 10, 2022
 */
public class FormDataObjectToJSON {

	private static final Logger LOG = LoggerFactory.getLogger(FormDataObjectToJSON.class);

	/**
	 * Convert.
	 *
	 * @param listGeonaFormObjects the list geona form objects
	 * @return the JSON object
	 * @throws JSONException the JSON exception
	 */
	public JSONObject convert(List<GeoNaFormDataObject> listGeonaFormObjects) throws JSONException {

		JSONObject theDocument = JSONObjecOrdered.instance();
		for (GeoNaFormDataObject geoNaFormDataObject : listGeonaFormObjects) {

			List<GenericDatasetBean> listGDB = geoNaFormDataObject.getListGDB();

			GcubeProfileDV profile = geoNaFormDataObject.getGcubeProfileDV();
			LOG.debug("The profile is: " + profile);

			String jsonPathExp = String.format("%s%s", profile.getParentName(), profile.getSectionName());
			LOG.debug("The json path to build: " + jsonPathExp);
			// jsonPathExp = "$.chidl1.child2.child3";

			String toJsonPathExp = jsonPathExp.replaceFirst("\\$", "");
			String[] jsonPathDeep = toJsonPathExp.split("\\.");
			List<JSONObject> listJSONObject = toListJonObject(listGDB, jsonPathDeep);

			// adding as JSONObject to theDocument at first deep level (under the root or at section specified)
			if (listJSONObject.size() == 1) {
				theDocument = deepMerge(listJSONObject.get(0), theDocument);
				//theDocument = theDocument.put(listJSONObject.get(0), jsonArray);
			} else {
				// adding as JSONArray to theDocument under the section specified
				// to jsonPathDeep[1]
				JSONArray jsonArray = new JSONArray();
				for (JSONObject jsonObject : listJSONObject) {
					// reading the i-mo JSONObject created in the list with the key as
					// jsonPathDeep[1]
					jsonArray.put(jsonObject.get(jsonPathDeep[1]));
				}
				theDocument.put(jsonPathDeep[1], jsonArray);

			}
			LOG.debug("Partial Root Document is: " + theDocument);
		}
		
		LOG.debug("Final JSON Document is: " + theDocument);
		return theDocument;
	}

	/**
	 * Generic dataset bean to JSON.
	 *
	 * @param gdb the gdb
	 * @return the JSON object
	 * @throws JSONException the JSON exception
	 */
	private JSONObject genericDatasetBeanToJSON(GenericDatasetBean gdb) throws JSONException {

		JSONObject sectJSONObject = JSONObjecOrdered.instance();

		LinkedHashMap<String, List<String>> mapFields = gdb.getFormDataEntryFields();
		LOG.debug("Map ordered: " + mapFields);
		for (String key : mapFields.keySet()) {
			List<String> listValues = mapFields.get(key);
			if (listValues == null || listValues.isEmpty()) {
				continue;
			}

			// key/value as string
			if (listValues.size() == 1) {
				sectJSONObject.put(key, listValues.get(0));
				continue;
			}

			// value is a list
			JSONArray array = new JSONArray();
			for (String value : listValues) {
				array.put(value);
			}

			sectJSONObject.put(key, array);
		}

		return sectJSONObject;

	}

	/**
	 * To list jon object.
	 *
	 * @param listGDB the list GDB
	 * @param jsonPathDeep the json path deep
	 * @return the list
	 * @throws JSONException the JSON exception
	 */
	private List<JSONObject> toListJonObject(List<GenericDatasetBean> listGDB, String[] jsonPathDeep)
			throws JSONException {

		List<JSONObject> listJSONObject = new ArrayList<JSONObject>();

		for (GenericDatasetBean gdb : listGDB) {
			JSONObject sectRootObject = JSONObjecOrdered.instance();
			JSONObject jsonObject = genericDatasetBeanToJSON(gdb);
			LOG.debug("Adding section : " + jsonObject);
			LOG.trace("jsonPathDeep: " + Arrays.asList(jsonPathDeep) + " size: " + jsonPathDeep.length);

			// Adding JSONObject to ROOT DOCUMENT POSITION (using PLACEHOLDER_ROOT_POINTER_JSON_DOC)
			if (jsonPathDeep.length == 0) {
				sectRootObject = deepMerge(jsonObject, sectRootObject);
			} else {

				// DEPTH >= 1
				sectRootObject.put(jsonPathDeep[jsonPathDeep.length - 1], jsonObject);
				JSONObject deepJSON = sectRootObject;
				System.out.println("sectRootObject: " + sectRootObject.toString());
				for (int i = jsonPathDeep.length - 2; i > 0; i--) {
					JSONObject newOne = JSONObjecOrdered.instance();
					newOne.put(jsonPathDeep[i], deepJSON);
					deepJSON = newOne;
				}
				sectRootObject = deepJSON;
			}

			listJSONObject.add(sectRootObject);

		}

		LOG.info("For listGDB : " + listGDB);
		LOG.info("returning : " + listJSONObject);
		return listJSONObject;

	}

	/**
	 * Merge "source" into "target". If fields have equal name, merge them
	 * recursively.
	 *
	 * @param source the source
	 * @param target the target
	 * @return the merged object (target).
	 * @throws JSONException the JSON exception
	 */
	public static JSONObject deepMerge(JSONObject source, JSONObject target) throws JSONException {
		for (String key : JSONObject.getNames(source)) {
			Object value = source.get(key);
			if (!target.has(key)) {
				// new value for "key":
				target.put(key, value);
			} else {
				// existing value for "key" - recursively deep merge:
				if (value instanceof JSONObject) {
					JSONObject valueJson = (JSONObject) value;
					deepMerge(valueJson, target.getJSONObject(key));
				} else {
					target.put(key, value);
				}
			}
		}
		return target;
	}

	
	/**
	 * The Class JSONObjecOrdered.
	 *
	 * @author Francesco Mangiacrapa at ISTI-CNR francesco.mangiacrapa@isti.cnr.it
	 * 
	 * Mar 10, 2022
	 */
	public static class JSONObjecOrdered {

		/**
		 * Instance.
		 *
		 * @return the JSON object
		 */
		public static JSONObject instance() {
			JSONObject jsonObject = new JSONObject();
			try {
				Field changeMap = jsonObject.getClass().getDeclaredField("map");
				changeMap.setAccessible(true);
				changeMap.set(jsonObject, new LinkedHashMap<>());
				changeMap.setAccessible(false);
			} catch (IllegalAccessException | NoSuchFieldException e) {
			}
			return jsonObject;
		}
	}

}