// This Source Code is in the Public Domain per: http://unlicense.org
package org.litesoft.orsup.base;

import org.litesoft.changemanagement.*;
import org.litesoft.commonfoundation.base.*;
import org.litesoft.core.*;
import org.litesoft.orsup.transact.*;

import java.io.*;

public class CacheMaintainer implements TransactionCommitListener {
    public static void create( Finder pFinder, CacheMaintenanceListener pListener ) {
        Confirm.isNotNull( "Finder", pFinder );
        Confirm.isNotNull( "Listener", pListener );
        CacheMaintainer zMaintainer = new CacheMaintainer( pListener, pFinder.getNextSequenceNumber( "CacheMaintainer" ) );
        pFinder.getTransactionCommitListenerManager().addListener( zMaintainer );
        zMaintainer.registerForChangesFromClusterPeers();
    }

    private void registerForChangesFromClusterPeers() {
        getMasterCLM().addListener( new MyChangeListener(), mListener.getClass() );
    }

    private void sendChangesToClusterPeers( Serializable pCacheUpdate ) {
        String zName = mListener.getClass().getName();
        ServerStateChange zChange = new ServerStateChange( ServerStateChange.Action.UPDATED, //
                                                           zName, // ChangedObjectTypeName
                                                           mOurID, // ChangedObjectUniqueKey
                                                           null, // ChangedObjectDisplayValue
                                                           pCacheUpdate );
        getMasterCLM().notifyAllRemoteListeners( new ServerStateChangeSet( mOurID, // SourceUniqueID
                                                                           zName, // SourceClassname
                                                                           zChange ) );
    }

    private ChangeListenerManager getMasterCLM() {
        DataStore zMasterDataStore = ServerStores.getMaster().get( DataStore.class );
        Confirm.isNotNull( "MasterDataStore", zMasterDataStore );
        return zMasterDataStore.getChangeListenerManager();
    }

    private CacheMaintainer( CacheMaintenanceListener pListener, Long pOurID ) {
        mListener = pListener;
        mOurID = pOurID;
    }

    private CacheMaintenanceListener mListener;
    private Long mOurID;

    @Override
    public TransactionSuccessfulCommitCallBack aboutToCommit( PersistentObject[] pCommitParticipants ) {
        Serializable zResult = mListener.aboutToCommit( pCommitParticipants );
        return (zResult != null) ? new MyCallBack( zResult ) : null;
    }

    private class MyCallBack implements TransactionSuccessfulCommitCallBack {
        private Serializable mResult;

        public MyCallBack( Serializable pResult ) {
            mResult = pResult;
        }

        @Override
        public void commitSucceeded() {
            sendChangesToClusterPeers( mResult );
            mListener.updateCache( mResult );
        }
    }

    private class MyChangeListener implements ServerStateChangedListener {
        @Override
        public void serverStateChanged( ServerStateChangeSet pServerStateChangeSet ) {
            for ( ServerStateChange zChange : pServerStateChangeSet.getChanges() ) {
                mListener.updateCache( (Serializable) zChange.getExtraInfo() );
            }
        }
    }
}