import com.teragrep.rlp_01.RelpBatch;
import com.teragrep.rlp_01.RelpConnection;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.security.AlgorithmConstraints;
import java.security.GeneralSecurityException;
import java.util.Date;
import java.util.concurrent.TimeoutException;
import java.util.function.Supplier;

import com.cloudbees.syslog.Facility;
import com.cloudbees.syslog.Severity;
import com.cloudbees.syslog.SyslogMessage;

import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLEngine;
import javax.net.ssl.SSLParameters;

class Main {

    public static void main(String[] args) {

        final String serverHostname = "127.0.0.1";
        final int serverPort = 601;

        boolean useTls = false;

        RelpConnection relpConnection;
        if (useTls) {
            try {
                SSLContext sslContext = SSLContextFactory.authenticatedContext(
                        "keystore.jks",
                        "changeit",
                        "TLSv1.3"
                );

                Supplier<SSLEngine> sslEngineSupplier = sslContext::createSSLEngine;
                /*
                // in case there is a need to configure these:
                SSLEngine sslEngine = sslContext.createSSLEngine();
                SSLParameters sslParameters = new SSLParameters();
                sslParameters.setAlgorithmConstraints();
                sslParameters.setCipherSuites();
                sslEngine.setSSLParameters(sslParameters);
                 */

                relpConnection = new RelpConnection(sslEngineSupplier);
            } catch (GeneralSecurityException | IOException exception) {
                exception.printStackTrace();
            }
        } else {
            relpConnection = new RelpConnection();
        }

        Main.openConnection(relpConnection, serverHostname, serverPort); // connection helper method

        RelpBatch relpBatch = new RelpBatch(); // create new relpBatch

        // Craft syslog message
        SyslogMessage syslog = new SyslogMessage()
                .withTimestamp(new Date().getTime())
                .withSeverity(Severity.WARNING)
                .withAppName("appName")
                .withHostname("hostName")
                .withFacility(Facility.USER)
                .withMsg("Hello RELP World!");


        relpBatch.insert(syslog.toRfc5424SyslogMessage().getBytes(StandardCharsets.UTF_8)); // insert one message

        boolean notSent = true;
        while (notSent) { // retry until sent

            try {
                relpConnection.commit(relpBatch); // send batch
            } catch (IOException | TimeoutException e) {
                e.printStackTrace();
            }

            if (!relpBatch.verifyTransactionAll()) { // failed batch
                relpBatch.retryAllFailed(); // re-queue failed events
                relpConnection.tearDown(); // teardown connection
                Main.openConnection(relpConnection, serverHostname, serverPort); // reconnect
            } else { // successful batch
                notSent = false;
            }
        }
    }

    private static void openConnection(RelpConnection relpConnection,
                                       String serverHostname,
                                       int serverPort) {
        // connect helper method
        boolean connected = false;
        while (!connected) {
            try {
                connected = relpConnection.connect(serverHostname, serverPort);  // connect
            } catch (IOException | TimeoutException e) { // error happened during the connect
                e.printStackTrace();
                relpConnection.tearDown(); // retry with clean connection
            }

            if (!connected) {
                // reconnect after an interval
                try {
                    Thread.sleep(500); // reconnect interval
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}