/*
 * Copyright 2017 The Android Open Source Project
 *
 * 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.conscrypt;

import static org.conscrypt.TestUtils.newTextMessage;

import java.io.OutputStream;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;

/**
 * Benchmark for comparing performance of client socket implementations.
 */
public final class ClientSocketBenchmark {
    /**
     * Provider for the benchmark configuration
     */
    interface Config {
        EndpointFactory clientFactory();
        EndpointFactory serverFactory();
        int messageSize();
        String cipher();
        ChannelType channelType();
        BenchmarkProtocol protocol();
    }

    private ClientEndpoint client;
    private ServerEndpoint server;
    private byte[] message;
    private ExecutorService executor;
    private Future<?> sendingFuture;
    private volatile boolean stopping;

    private static final AtomicLong bytesCounter = new AtomicLong();
    private AtomicBoolean recording = new AtomicBoolean();

    ClientSocketBenchmark(Config config) throws Exception {
        recording.set(false);

        message = newTextMessage(config.messageSize());

        // Always use the same server for consistency across the benchmarks.
        server = config.serverFactory().newServer(
                ChannelType.CHANNEL, config.messageSize(), config.protocol().getProtocols(),
                ciphers(config));

        server.setMessageProcessor(new ServerEndpoint.MessageProcessor() {
            @Override
            public void processMessage(byte[] inMessage, int numBytes, OutputStream os) {
                if (recording.get()) {
                    // Server received a message, increment the count.
                    bytesCounter.addAndGet(numBytes);
                }
            }
        });
        Future<?> connectedFuture = server.start();

        client = config.clientFactory().newClient(
            config.channelType(), server.port(), config.protocol().getProtocols(), ciphers(config));
        client.start();

        // Wait for the initial connection to complete.
        connectedFuture.get(5, TimeUnit.SECONDS);

        executor = Executors.newSingleThreadExecutor();
        sendingFuture = executor.submit(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread thread = Thread.currentThread();
                    while (!stopping && !thread.isInterrupted()) {
                        client.sendMessage(message);
                    }
                } finally {
                    client.flush();
                }
            }
        });
    }

    void close() throws Exception {
        stopping = true;

        // Wait for the sending thread to stop.
        sendingFuture.get(5, TimeUnit.SECONDS);

        client.stop();
        server.stop();
        executor.shutdown();
        executor.awaitTermination(5, TimeUnit.SECONDS);
    }

    /**
     * Simple benchmark for the amount of time to send a given number of messages (used by
     * Caliper).
     */
    void time(final int numMessages) throws Exception {
        reset();
        recording.set(true);

        while (bytesCounter.get() < numMessages) {
            Thread.sleep(50);
        }

        recording.set(false);
    }

    /**
     * Simple benchmark for throughput (used by JMH).
     */
    void throughput() throws Exception {
        recording.set(true);
        // Send as many messages as we can in a second.
        Thread.sleep(1001);
        recording.set(false);
    }

    static void reset() {
        bytesCounter.set(0);
    }

    static long bytesPerSecond() {
        return bytesCounter.get();
    }

    private String[] ciphers(Config config) {
        return new String[] {config.cipher()};
    }
}