package eu.openaire.urls_worker;

import eu.openaire.publications_retriever.PublicationsRetriever;
import eu.openaire.publications_retriever.util.file.FileUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;

import javax.annotation.PreDestroy;
import java.io.File;
import java.util.Scanner;
import java.util.concurrent.TimeUnit;


@SpringBootApplication
@EnableScheduling
public class UrlsWorkerApplication {

    private static final Logger logger = LoggerFactory.getLogger(UrlsWorkerApplication.class);

    private static final String inputDataFilePath = FileUtils.workingDir + "inputData.txt";
    public static String workerId = null;
    public static String controllerBaseUrl = null;  // BaseUrl template: "http://IP:PORT/api/"


    public static void main(String[] args) {

        setInputData(); // This may cause the Server to terminate early, in case the workerId or the controllerBaseUrl cannot be found.

        SpringApplication.run(UrlsWorkerApplication.class, args);
    }


    @PreDestroy
    public static void preDestroy()
    {
        if ( PublicationsRetriever.executor != null )
        {
            PublicationsRetriever.executor.shutdown();	// Define that no new tasks will be scheduled.
            try {
                if ( !PublicationsRetriever.executor.awaitTermination(1, TimeUnit.MINUTES) ) {
                    logger.warn("The working threads did not finish on time! Stopping them immediately..");
                    PublicationsRetriever.executor.shutdownNow();
                }
            } catch (InterruptedException e) {
                PublicationsRetriever.executor.shutdownNow();
            }
        }
    }


    private static void setInputData()
    {
        // Take the workerId and the controllerBaseUrl from the file.
        Scanner myReader = null;
        try {
            File inputDataFile = new File(inputDataFilePath);
            if ( !inputDataFile.exists() ) {
                String errorMsg = "controllerBaseUrlFile \"" + inputDataFilePath + "\" does not exists!";
                logger.error(errorMsg);
                System.err.println(errorMsg);
                System.exit(60);
            }
            myReader = new Scanner(inputDataFile);
            if ( myReader.hasNextLine() ) {
                String[] data = myReader.nextLine().split(",");
                if ( data.length < 2 ) {
                    String errorMsg = "Not all data were retrieved from file \"" + inputDataFilePath + "\"!";
                    logger.error(errorMsg);
                    System.err.println(errorMsg);
                    System.exit(61);
                }
                workerId = data[0].trim();
                controllerBaseUrl = data[1].trim();
                if ( !controllerBaseUrl.endsWith("/") )
                    controllerBaseUrl += "/";   // Make sure the whole urls will not break later.
            }

            if ( (workerId == null) || (controllerBaseUrl == null) ) {
                String errorMsg = "No \"workerId\" or/and \"controllerBaseUrl\" could be retrieved from the file: " + inputDataFilePath;
                logger.error(errorMsg);
                System.err.println(errorMsg);
                System.exit(62);
            }

            logger.info("workerId: " + workerId + ", controllerBaseUrl: " + controllerBaseUrl);    // It's safe and helpful to show them in the logs.

        } catch (Exception e) {
            String errorMsg = "An error prevented the retrieval of the workerId and the controllerBaseUrl from the file: " + inputDataFilePath + "\n" + e.getMessage();
            logger.error(errorMsg);
            System.err.println(errorMsg);
            e.printStackTrace();
            System.exit(63);
        } finally {
            if ( myReader != null )
                myReader.close();
        }
    }

}