// This Source Code is in the Public Domain per: http://unlicense.org
package org.litesoft.bo.views.mock;

import org.litesoft.bo.change.*;
import org.litesoft.bo.views.*;
import org.litesoft.bo.views.communication.*;
import org.litesoft.bo.views.server.*;
import org.litesoft.commonfoundation.exceptions.*;
import org.litesoft.commonfoundation.iterators.*;
import org.litesoft.core.simpletypes.*;
import org.litesoft.commonfoundation.typeutils.Objects;
import org.litesoft.core.util.*;
import org.litesoft.logger.*;

import java.util.*;

public abstract class MockServerVoPersister<T extends IViewObject<?>> extends AbstractServerVoPersister<T>
{
    public static final Logger LOGGER = LoggerFactory.getLogger( MockServerVoPersister.class );

    private Table<T> mTable;

    protected MockServerVoPersister( VoMetaData<T> pMetaData, T... pRows )
    {
        super( pMetaData );
        mTable = new Table<T>( pMetaData );
        if ( pRows != null )
        {
            for ( T zRow : pRows )
            {
                mTable.addRow( zRow );
            }
        }
    }

    public T getVOby( ObjectURL pObjectURL )
            throws PersistenceException
    {
        return augment( (pObjectURL != null) ? mTable.getBy( pObjectURL ) : null );
    }

    public T getMatchingVO( SSMap... pORed_ANDFilters )
            throws PersistenceException
    {
        SizedIterator<T> zIterator = getMatchingVOs( null, pORed_ANDFilters );
        try
        {
            T zFound = null;
            if ( zIterator.hasNext() )
            {
                zFound = zIterator.next();
                if ( zIterator.hasNext() )
                {
                    throw new MultipleMatchingPersistenceException( "More than one " + mTable.getObjectName() + " resulted from Filters: " + Objects
                            .toString( pORed_ANDFilters ) );
                }
            }
            return augment( zFound );
        }
        finally
        {
            zIterator.dispose();
        }
    }

    public SizedIterator<T> getMatchingVOs( Integer pMaxToReturn, SSMap... pORed_ANDFilters )
            throws PersistenceException
    {
        LOGGER.error.log( "*** MOCK ***" );
        List<T> zNoResults = Collections.emptyList();
        return new SizedIterator<T>( zNoResults.iterator() );
    }

    protected Collection<T> optionallyOrderRows( Collection<T> pRows )
    {
        return pRows;
    }

    public SCresult commit( TransactionSet pTransactionSet, ObjectURL... pReturnOnSuccess )
            throws PersistenceException
    {
        SCresult rv = new SCresult();

        StringBuilder zProblems = new StringBuilder();

        Map<ObjectURL, T> zURLsToSaved = new HashMap<ObjectURL, T>();

        Set<ViewObject> zMembers = pTransactionSet.getAllMembers();
        if ( !zMembers.isEmpty() )
        {
            Table<T> zTable = new Table<T>( mTable );
            for ( ViewObject<?> zMember : zMembers )
            {
                if ( zMember instanceof Precommitable )
                {
                    ((Precommitable) zMember).aboutToCommit();
                }
                T zMemberInstance = castToIfSameType( zMember );
                if ( zMemberInstance == null )
                {
                    zProblems.append( "\nCommit on " ).append( Objects.justClassNameOf( this ) ).append( " only supports TransactionSet members of type '" ).append( mTable.getObjectName() ).append( "', but found a type of '" ).append( zMember.getVoMetaData().getObjectName() ).append( "': " ).append( zMember );
                    continue;
                }
                if ( zMemberInstance.isNew() )
                {
                    T zNewInstance = zTable.insert( zMemberInstance );
                    zURLsToSaved.put( zNewInstance.getObjectURL(), zNewInstance );
                    zURLsToSaved.put( zMemberInstance.getObjectURL(), zNewInstance );
                }
                else
                {
                    T zExisting = zTable.getBy( zMemberInstance.getObjectURL() );
                    if ( zExisting == null )
                    {
                        zProblems.append( "\nCommit could not match a non-New type '" ).append( zMemberInstance.getVoMetaData().getObjectName() ).append( ": " ).append( zMemberInstance );
                    }
                    else
                    {
                        T zUpdatedInstance = zTable.update( zMemberInstance );
                        zURLsToSaved.put( rv.add( zUpdatedInstance.getObjectURL() ), zUpdatedInstance );
                    }
                }
            }
            if ( zProblems.length() != 0 )
            {
                return VOSC.result( zProblems.toString() );
            }

            mTable = zTable;
        }
        // Note: that this occurs BEFORE the News are 'unNew'd.  This means that the pReturnOnSuccess
        ArrayList<T> zRequestedBack = new ArrayList<T>(); // ObjectURLs may reference "new" VOs
        if ( pReturnOnSuccess != null )
        {
            for ( ObjectURL zObjectURL : pReturnOnSuccess )
            {
                zRequestedBack.add( augment( zURLsToSaved.get( zObjectURL ) ) );
            }
        }

        for ( ViewObject<?> zVO : zMembers )
        {
            committedVO( zVO, zURLsToSaved.get( zVO.getObjectURL() ) );
        }

        pTransactionSet.clear();

        return rv.setSCresponse( new VOSCresponseRows( new ImmutableArrayList<T>( zRequestedBack ) ) );
    }

    @SuppressWarnings({"unchecked"})
    private void committedVO( ViewObject<?> zVO, T pT )
    {
        zVO.committed( (pT != null) ? pT.getID() : null );
    }

    private T castToIfSameType( ViewObject<?> pMember )
    {
        return pMember.getVoMetaData().getObjectName().equals( mTable.getObjectName() ) ? castTo( pMember ) : null;
    }

    @SuppressWarnings({"unchecked"})
    private T castTo( ViewObject<?> pMember )
    {
        return (T) pMember;
    }

    private static class Table<VO extends IViewObject>
    {
        private VoMetaData<VO> mMetaData;
        private Map<ObjectURL, VO> mTable = new HashMap<ObjectURL, VO>();

        public Table( VoMetaData<VO> pMetaData )
        {
            mMetaData = pMetaData;
        }

        public Table( Table<VO> pTable )
        {
            mMetaData = pTable.getMetaData();
            mTable.putAll( pTable.mTable );
        }

        public VoMetaData<VO> getMetaData()
        {
            return mMetaData;
        }

        public String getObjectName()
        {
            return mMetaData.getObjectName();
        }

        public VO getBy( ObjectURL pObjectURL )
        {
            return mTable.get( pObjectURL );
        }

        public Collection<VO> getRows()
        {
            return mTable.values();
        }

        public VO addRow( VO pRow )
        {
            if ( pRow != null )
            {
                mTable.put( pRow.getObjectURL(), pRow );
            }
            return pRow;
        }

        public VO insert( VO pInstance )
        {
            VO rv = populateFromTo( pInstance, createNewInstance() );
            rv.setAttributeValue( "ID", MockIdProvider.nextID() );
            rv.initialize();
            return addRow( rv );
        }

        public VO update( VO pInstance )
        {
            VO rv = populateFromTo( pInstance, createNewInstance() );
            rv.initialize();
            return addRow( rv );
        }

        private VO populateFromTo( VO pInstance, VO pNewObject )
        {
            for ( String zName : pInstance.getBoMetaData().getAttributeNames() )
            {
                pNewObject.setAttributeValue( zName, pInstance.getAttributeValue( zName ) );
            }
            return pNewObject;
        }

        @SuppressWarnings({"unchecked"})
        private VO createNewInstance()
        {
            return mMetaData.createViewObject( false, null );
        }
    }
}