/*
 * Copyright 2017-2018 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
 *
 *      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.
 */
package org.springframework.data.mongodb.microbenchmark;

import lombok.SneakyThrows;

import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import java.nio.charset.StandardCharsets;
import java.util.Collection;

import org.openjdk.jmh.results.RunResult;
import org.openjdk.jmh.results.format.ResultFormatFactory;
import org.openjdk.jmh.results.format.ResultFormatType;

/**
 * @author Christoph Strobl
 * @since 2.0
 */
interface ResultsWriter {

	/**
	 * Write the {@link RunResult}s.
	 *
	 * @param results can be {@literal null}.
	 */
	void write(Collection<RunResult> results);

	/**
	 * Get the uri specific {@link ResultsWriter}.
	 *
	 * @param uri must not be {@literal null}.
	 * @return
	 */
	static ResultsWriter forUri(String uri) {
		return uri.startsWith("mongodb:") ? new MongoResultsWriter(uri) : new HttpResultsWriter(uri);
	}

	/**
	 * Convert {@link RunResult}s to JMH Json representation.
	 *
	 * @param results
	 * @return json string representation of results.
	 * @see org.openjdk.jmh.results.format.JSONResultFormat
	 */
	@SneakyThrows
	static String jsonifyResults(Collection<RunResult> results) {

		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		ResultFormatFactory.getInstance(ResultFormatType.JSON, new PrintStream(baos, true, "UTF-8")).writeOut(results);

		return new String(baos.toByteArray(), StandardCharsets.UTF_8);
	}
}
