package com.sun.enterprise.shoal.carryel;

import com.sun.enterprise.ee.cms.core.*;

import java.util.logging.Logger;
import java.util.logging.Level;
import java.util.UUID;
import java.util.Map;
import java.util.Random;

public class RaiseFenceTest {

    private static final Logger logger = Logger.getLogger( "RaiseFenceTest" );

    private static final Random RANDOM = new Random();
    private static final String GROUP_NAME = "TestGroup";
    private static final String COMPONENT_NAME = "TestComponent";
    private static final String FAILED_MEMBER_TOKEN = "I_am_already_failed_member";

    public static void main( String[] args ) {
        RaiseFenceTest check = new RaiseFenceTest();
        try {
            check.runSimpleSample();
        } catch( GMSException e ) {
            logger.log( Level.SEVERE, "Exception occured while joining group:" + e );
        }
    }

    private void runSimpleSample() throws GMSException {
        logger.log( Level.INFO, "Starting RaiseFenceTest...." );

        String serverName = UUID.randomUUID().toString();

        //initialize Group Management Service
        GroupManagementService gms = initializeGMS( serverName, GROUP_NAME );

        //join group
        logger.log( Level.INFO, "Joining Group " + GROUP_NAME );
        gms.join();

        try {
            Thread.sleep( 3000 );
        } catch( InterruptedException e ) {
        }
        // raise fence
        GroupHandle gh = gms.getGroupHandle();
        while( true ) {
            try {
                gh.raiseFence( COMPONENT_NAME, FAILED_MEMBER_TOKEN );
                logger.log( Level.INFO, "raiseFence() called successfully" );
                checkRaiseFence( gh, COMPONENT_NAME, FAILED_MEMBER_TOKEN );
            } catch( GMSException gmse ) {
                gmse.printStackTrace();
            } catch( RuntimeException re ) {
                re.printStackTrace();
                leaveGroupAndShutdown( serverName, gms );
                System.exit( 0 );
            } finally {
                gh.lowerFence( COMPONENT_NAME, FAILED_MEMBER_TOKEN );
                logger.log( Level.INFO, "lowerFence() called successfully" );
            }
            try {
                Thread.sleep( getRandomSleep() );
            } catch( InterruptedException e ) {
            }
        }
    }

    private void checkRaiseFence( GroupHandle gh, String componentName, String memberToken ) {
        DistributedStateCache dsc = gh.getDistributedStateCache();
        final Map<GMSCacheable, Object> entries;
        entries = dsc.getFromCache( memberToken );
        int raisedCount = 0;
        for( GMSCacheable c : entries.keySet() ) {
            if( componentName.equals( c.getComponentName() ) ) {
                if( memberToken.equals( c.getKey() ) ) {
                    if( !memberToken.equals( c.getMemberTokenId() ) ) {
                        raisedCount++;
                    }
                }
            }
        }
        if( raisedCount > 1 )
            throw new RuntimeException( "raised count should not exceed 1" );
    }

    private static int getRandomSleep() {
        return RANDOM.nextInt( 3 ) * 1000;
    }

    private GroupManagementService initializeGMS( String serverName, String groupName ) {
        logger.log( Level.INFO, "Initializing Shoal for member: " + serverName + " group:" + groupName );
        return (GroupManagementService)GMSFactory.startGMSModule( serverName,
                                                                  groupName,
                                                                  GroupManagementService.MemberType.CORE,
                                                                  null );
    }

    private void leaveGroupAndShutdown( String serverName, GroupManagementService gms ) {
        logger.log( Level.INFO, "Shutting down gms " + gms + "for server " + serverName );
        gms.shutdown( GMSConstants.shutdownType.INSTANCE_SHUTDOWN );
    }
}