// This Source Code is in the Public Domain per: http://litesoft.org/License.txt
package org.litesoft.orsup.lazyload;

import org.litesoft.orsup.base.*;
import org.litesoft.orsup.nonpublic.*;
import org.litesoft.orsup.otherattributeaccessors.*;

public class LazyLoadToOnePaired<Owner extends PersistentObjectImpl, Them extends PersistentObjectImpl> extends AbstractLazyLoadToOne<Owner, Them>
{
    protected AttributeAccessorSCDtoOnePaired<Owner, Them> mSCDtoOnePaired;
    protected MetaDataForPO mThierMetaData;

    public LazyLoadToOnePaired( Owner pOwner, AttributeAccessorSCDtoOnePaired<Owner, Them> pSCDtoOnePaired )
    {
        super( pOwner, pSCDtoOnePaired );
        mSCDtoOnePaired = pSCDtoOnePaired;
        mThierMetaData = getPOMetaDataRequired( pSCDtoOnePaired.getToThemName() );
    }

    @Override
    public final AttributeAccessorSCDtoOnePaired<Owner, Them> getSCDtoOne()
    {
        return mSCDtoOnePaired;
    }

    public final Them getValue()
    {
        if ( !mLoaded )
        {
            //noinspection unchecked
            mValue = (Them) LL_loadValueWithNonNull( mDBValue );
            mLoaded = true;
        }
        return mValue;
    }

    /**
     * Note Only called when the New Them is NOT the same as the Old Them
     *
     * @param pNewThem Nullable
     */
    public final void setValue( Them pNewThem )
    {
        getSCDtoOne().setValueOnPO( mOwner, pNewThem ); // Force Exception
    }

    @Override
    protected String getBackRefOnUnWire( String pBackRefAttributeNameOnNewThem )
    {
        throw new IllegalStateException( "getBackRefOnUnWire should not be called on PairedToOne" );
    }

    /**
     * @param pDBValue !null
     */
    @Override
    protected final PersistentObject<?> LL_loadValueWithNonNull( Object pDBValue )
    {
        return mOwner.getFinder().findOne( mThierMetaData.getPOregistrationName(), // assumes that that our Key Type is the same as thier Key Type
                                           mOwner.getPersistentObjectUniqueKey() );
    }

    /**
     * @param pNewThem !null
     */
    @Override
    protected final Object LL_extract_db_value( PersistentObjectImpl pNewThem, String pBackRefAttributeNameOnNewThem )
    {
        throw new IllegalStateException( "LL_extract_db_value should not be called on PairedToOne" );
    }
}