package org.litesoft.aokeyhole.objects.support;

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

public class ObjectProxy extends AbstractBase
{
    private AbstractNamedMetaData mOwner;
    private String mPurpose;

    private SystemMetaData mSystemMetaData = null;
    private IdentifierValidator mNameValidator = null;

    private ObjectMetaData mObjectMetaData = null;
    private String mObjectName = null;

    public ObjectProxy( AbstractNamedMetaData pOwner, String pPurpose )
    {
        mOwner = pOwner;
        mPurpose = pPurpose;
    }

    /**
     * @throws ParseException if the previously set Object can NOT be found
     */
    public void unpersistFini( SystemMetaData pSystemMetaData, IdentifierValidator pNameValidator, ObjectMetaData pButNotThisObject, String pErrorIfNotThisObject )
            throws ParseException
    {
        mSystemMetaData = pSystemMetaData;
        mNameValidator = pNameValidator;

        String newObjectName = mObjectName;
        mObjectName = null;

        String error = fetchObjectIfNeeded( newObjectName, pButNotThisObject, pErrorIfNotThisObject );
        if ( error != null )
        {
            throw new ParseException( error );
        }
    }

    public String getObjectName()
    {
        return (mObjectMetaData == null) ? mObjectName : mObjectMetaData.getName();
    }

    /**
     * @return true if a Change
     *
     * @throws IllegalArgumentException if Object is not found
     */
    public boolean setObjectName( String pNewObjectName, ObjectMetaData pButNotThisObject, String pErrorIfNotThisObject )
            throws IllegalArgumentException
    {
        String newObjectName = trimEmptyToNull( pNewObjectName );
        if ( areEqual( getObjectName(), pNewObjectName ) )
        {
            return false;
        }
        if ( "VaribleToOne".equals( newObjectName ))
        {
            System.out.println( "ObjectProxy.setObjectName" );
        }
        if ( mSystemMetaData == null )
        {
            mObjectName = newObjectName;
            return true;
        }
        ObjectMetaData cur = mObjectMetaData;
        String error = fetchObjectIfNeeded( newObjectName, pButNotThisObject, pErrorIfNotThisObject );
        if ( error != null )
        {
            throw new ParseException( error );
        }
        return !areEqual( cur, mObjectMetaData );
    }

    private String fetchObjectIfNeeded( String pNewObjectName, ObjectMetaData pButNotThisObject, String pErrorIfNotThisObject )
    {
        if ( pNewObjectName == null )
        {
            mObjectMetaData = null;
            return null;
        }
        String zError = mNameValidator.validateIdentifier( pNewObjectName, mPurpose + " Object Name" );
        if ( zError != null )
        {
            return "On " + mOwner.getName() + ": " + zError;
        }
        ObjectMetaData newObject = mSystemMetaData.getObject( pNewObjectName );
        if ( newObject == null )
        {
            return "On " + mOwner.getName() + ", requested " + mPurpose + " Object not found: " + pNewObjectName;
        }
        if ( newObject == pButNotThisObject )
        {
            if ( pErrorIfNotThisObject != null )
            {
                return pErrorIfNotThisObject;
            }
            newObject = null;
        }
        mObjectMetaData = newObject;
        return null;
    }

    public ObjectMetaData getObjectMetaData()
    {
        return mObjectMetaData;
    }
}