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

import org.litesoft.aokeyhole.objects.attributes.*;
import org.litesoft.aokeyhole.objects.support.*;
import org.litesoft.aokeyhole.toolkit.*;

public abstract class AttributeMetaDataRelated extends AttributeMetaData {
    /**
     * null means related to self (owning object)
     */
    protected final ObjectProxy mRelatedTo;

    protected AttributeMetaDataRelated( AttributeSet pAttributeSet, Mode pMode, boolean pEditable, boolean pVirtual, PropertyMetaData[] pPropertyMetaDatas,
                                        IdentifierValidator pNameValidator, String pName ) {
        super( pAttributeSet, pMode, pEditable, pVirtual, pPropertyMetaDatas, pNameValidator, pName );

        mRelatedTo = new ObjectProxy( this, "Relate to" );
    }

    public boolean isToMany() {
        return A_ToMany.TYPE.equals( getAttributeSet().getType() );
    }

    @Override
    public boolean isRelated() {
        return true;
    }

    public String getRelatedTo() {
        return mRelatedTo.getObjectName();
    }

    public void unpersistRelatedTo( String pRelatedToName ) {
        chkUnhappyCase( updateRelatedTo( pRelatedToName ) );
    }

    /**
     * @return null or Error
     */
    public String setRelatedTo( String pRelatedToName ) {
        verifyEditability();
        return updateRelatedTo( pRelatedToName );
    }

    /**
     * @return null or Error
     */
    protected String updateRelatedTo( String pRelatedToName ) {
        ObjectMetaData zOwner = getOwner();
        try {
            if ( mRelatedTo.setObjectName( pRelatedToName, zOwner, null ) ) {
                changed();
            }
            return null;
        }
        catch ( IllegalArgumentException e ) {
            return e.getMessage();
        }
    }

    @Override
    public void setRehydrated() {
        ObjectMetaData zOwner = getOwner();
        mRelatedTo.unpersistFini( getSystemMetaData(), zOwner.getNameValidator(), zOwner, null );
        super.setRehydrated();
    }

    @Override
    protected String[] getAdditionalValues() {
        return new String[]{getAdditionalValueRelatedTo()};
    }

    protected String getAdditionalValueRelatedTo() {
        String zRelatedTo = getRelatedTo();
        return (zRelatedTo == null) || ObjectNames.VARIES_RELATED_TO.equals( zRelatedTo ) ? "" : zRelatedTo;
    }

    public boolean isRelatedTo( ObjectMetaData pToObject ) {
        return areEqual( pToObject, mRelatedTo.getObjectMetaData() );
    }

    @Override
    public void setUpView( NameValuesComponent pNameValuesComponent ) {
        super.setUpView( pNameValuesComponent );

        pNameValuesComponent.setValue( AttribNamesRelated.RELATED_TO, getRelatedTo() );
        if ( isEditable() ) {
            pNameValuesComponent.setOptions( AttribNamesRelated.RELATED_TO, //
                                             getObjectMetaData().getPotentialRelateToObjectNamesFor( getAttributeSet(), isVirtual() ) );
        }
    }

    @Override
    protected void saveFromViewCollectChanges( ChangeHandler pChanges, NameValuesComponent pNameValuesComponent ) {
        super.saveFromViewCollectChanges( pChanges, pNameValuesComponent );

        String zCurRelatedTo = deNull( getRelatedTo() );
        String zNewRelatedTo = deNull( pNameValuesComponent.getValue( AttribNamesRelated.RELATED_TO ) );
        ObjectMetaData zNewRelToObject = getObjectMetaData( zNewRelatedTo );

        augmentSaveFromView( pChanges, pNameValuesComponent, zCurRelatedTo, zNewRelToObject );
    }

    @Override
    public void clearRelatedToIf( ObjectMetaData pObjectMetaData, ChangeHandler pChanges ) {
        if ( mRelatedTo.getObjectMetaData() == pObjectMetaData ) // Note Identity ==
        {
            pChanges.add( new ChangeRelatedTo( null ) );
        }
    }

    protected ObjectMetaData getObjectMetaData( String pRelatedTo ) {
        if ( pRelatedTo.length() == 0 ) {
            return getObjectMetaData();
        }
        ObjectMetaData zObjectMetaData = getSystemMetaData().getObject( pRelatedTo );
        if ( zObjectMetaData != null ) {
            return zObjectMetaData;
        }
        throw new RuntimeException( "Unable to locate 'Related To' Object: " + pRelatedTo );
    }

    protected void augmentSaveFromView( ChangeHandler pChanges, NameValuesComponent pNameValuesComponent, String pCurRelatedTo, ObjectMetaData pNewRelToObject ) {
        pChanges.add( checkRelatedToChange( pCurRelatedTo, pNewRelToObject.getName() ) );
    }

    protected ChangeFragment checkRelatedToChange( String pCurRelatedTo, String pNewRelatedTo ) {
        return !areEqual( pCurRelatedTo, pNewRelatedTo ) ? new ChangeRelatedTo( pNewRelatedTo ) : null;
    }

    protected class ChangeRelatedTo implements ChangeFragment {
        private String mNewRelatedTo;

        public ChangeRelatedTo( String pNewRelatedTo ) {
            mNewRelatedTo = pNewRelatedTo;
        }

        @Override
        public void commitChange() {
            setRelatedTo( mNewRelatedTo );
        }
    }
}