package org.example;

import io.grpc.Grpc;
import io.grpc.InsecureServerCredentials;
import io.grpc.Server;
import io.grpc.Status;
import io.grpc.health.v1.HealthCheckRequest;
import io.grpc.health.v1.HealthCheckResponse;
import io.grpc.health.v1.HealthGrpc.HealthImplBase;
import io.grpc.stub.StreamObserver;

import java.io.IOException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.logging.Logger;

public class ServerStuck {
    private static final Logger logger = Logger.getLogger(ServerStuck.class.getName());


    private Server server;

    public void start() throws IOException {
        int port = 50051;

        ExecutorService executor = Executors.newFixedThreadPool(2);
        server = Grpc.newServerBuilderForPort(port, InsecureServerCredentials.create())
            .executor(executor)
            .addService(new HealthImplBase() {
                @Override
                public void check(HealthCheckRequest request, StreamObserver<HealthCheckResponse> responseObserver) {
                    try {
                        Thread.sleep(2);
                        responseObserver.onError(Status.ABORTED.asException());
                    } catch (InterruptedException e) {
                        responseObserver.onError(Status.INTERNAL.asException());
                    }
                }
            })
            .build()
            .start();
        logger.info("Server started, listening on " + port);

        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
            System.err.println("*** shutting down gRPC server since JVM is shutting down");
            try {
                ServerStuck.this.stop();
            } catch (InterruptedException e) {
                if (server != null) {
                    server.shutdownNow();
                }
                e.printStackTrace(System.err);
            } finally {
                executor.shutdown();
            }
            System.err.println("*** server shut down");
        }));
    }

    private void stop() throws InterruptedException {
        if (server != null) {
            server.shutdown().awaitTermination(30, TimeUnit.SECONDS);
        }
    }

    public void blockUntilShutdown() throws InterruptedException {
        if (server != null) {
            server.awaitTermination();
        }
    }
}