/**
 * ============LICENSE_START=======================================================
 * org.onap.aai
 * ================================================================================
 * Copyright © 2017-2018 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * 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
 *
 *    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.
 * ============LICENSE_END=========================================================
 */
package org.onap.aai.serialization.queryformats;

import com.att.eelf.configuration.EELFLogger;
import com.att.eelf.configuration.EELFManager;
import com.google.gson.JsonArray;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

import org.onap.aai.logging.LogFormatTools;
import org.onap.aai.serialization.queryformats.exceptions.AAIFormatQueryResultFormatNotSupported;
import org.onap.aai.serialization.queryformats.exceptions.AAIFormatVertexException;

import java.util.List;
import java.util.Optional;
import java.util.stream.Stream;

public class Formatter {

	private static final EELFLogger LOGGER = EELFManager.getInstance().getLogger(Formatter.class);

	protected JsonParser parser = new JsonParser();
	protected final FormatMapper format;

	public Formatter(FormatMapper format) {
		this.format = format;
	}

	public JsonObject output(List<Object> queryResults) {

		Stream<Object> stream = null;
		JsonObject result = new JsonObject();
		JsonArray body = new JsonArray();

		if (this.format instanceof Count) {
			JsonObject countResult;
			try {
				countResult = format.formatObject(queryResults);
				body.add(countResult);
			} catch (Exception e) {
				LOGGER.warn("Failed to format result type of the query " + LogFormatTools.getStackTop(e));
			}
		} else {
			if (queryResults.size() >= format.parallelThreshold()) {
				stream = queryResults.parallelStream();
			} else {
				stream = queryResults.stream();
			}

			final boolean isParallel = stream.isParallel();

			stream.map(o -> {
				try {
					return Optional.<JsonObject>of(format.formatObject(o));
				} catch (AAIFormatVertexException e) {
					LOGGER.warn("Failed to format vertex, returning a partial list " + LogFormatTools.getStackTop(e));
				} catch (AAIFormatQueryResultFormatNotSupported e) {
					LOGGER.warn("Failed to format result type of the query " + LogFormatTools.getStackTop(e));
				}

				return Optional.<JsonObject>empty();
			})
			.filter(Optional<JsonObject>::isPresent)
			.map(Optional<JsonObject>::get)
			.forEach(json -> {
					if (isParallel) {
						synchronized (body) {
							body.add(json);
						}
					} else {
						body.add(json);
					}
			});

		}
		result.add("results", body);
		return result.getAsJsonObject();
	}

}