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

import org.litesoft.commonfoundation.base.*;
import org.litesoft.orsup.selection.*;

/**
 * An implementation of a PersistentObjectUniqueKey that is PO Instance/Identity based for those POs that do NOT have a Unique Key
 */
public class PersistentObjectUniqueKeyForInstance extends PersistentObjectUniqueKey {
    private static final long serialVersionUID = 1L;

    transient private PersistentObject<?> mPersistentObject;
    private final int mPOsystemHashCode;

    public PersistentObjectUniqueKeyForInstance( PersistentObject<?> pPersistentObject ) {
        Confirm.isNotNull( "PersistentObject", mPersistentObject = pPersistentObject );
        mPOsystemHashCode = System.identityHashCode( mPersistentObject );
    }

    @Override
    protected int calcHashCode() {
        return mPOsystemHashCode;
    }

    @Override
    protected boolean equalsNotNullNotUs( PersistentObjectUniqueKey pThem ) {
        if ( pThem instanceof PersistentObjectUniqueKeyForInstance ) {
            PersistentObjectUniqueKeyForInstance them = (PersistentObjectUniqueKeyForInstance) pThem;
            if ( this.mPOsystemHashCode == them.mPOsystemHashCode ) {
                if ( (this.mPersistentObject == null) || (them.mPersistentObject == null) || (this.mPersistentObject == them.mPersistentObject) ) {
                    return true;
                }
            }
        }
        return false;
    }

    @Override
    protected String generateToStringForConstructor() {
        return null;  // ? Should this throw an exception?
    }

    @Override
    public WhereClause convertToWC() {
        throw new IllegalStateException( "Attempt to query on a PersistentObjectUniqueKey for an object that has no PersistentObjectUniqueKey" );
    }
}