/*
 * Copyright 2021 The Dapr 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 io.dapr.examples.pubsub.grpc;

import io.dapr.examples.DaprApplication;
import io.grpc.Server;
import io.grpc.ServerBuilder;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.DefaultParser;
import org.apache.commons.cli.Options;

/**
 * Service for subscriber.
 * 1. Build and install jars:
 * mvn clean install
 * 2. cd [repo root]/examples
 * 3. Run the server:
 * dapr run --components-path ./components/pubsub --app-id subscriber --app-port 3000 -- \
 *   java -jar target/dapr-java-sdk-examples-exec.jar io.dapr.examples.pubsub.grpc.Subscriber -p 3000
 */
public class Subscriber {

  /**
   * This is the entry point for this example app, which subscribes to a topic.
   * @param args The port this app will listen on.
   * @throws Exception An Exception on startup.
   */
  public static void main(String[] args) throws Exception {
    Options options = new Options();
    options.addRequiredOption("p", "port", true, "The port this app will listen on");

    CommandLineParser parser = new DefaultParser();
    CommandLine cmd = parser.parse(options, args);

    // If port string is not valid, it will throw an exception.
    int port = Integer.parseInt(cmd.getOptionValue("port"));

    //start a grpc server
    Server server = ServerBuilder.forPort(port)  
        .addService(new SubscriberGrpcService())  
        .build();  
    server.start();  
    server.awaitTermination();  

    // Start Dapr's callback endpoint.
    DaprApplication.start("grpc",port);
  }
}
