/*
* Copyright (c) 2009, Rickard Öberg. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.qi4j.spi.entitystore.helpers;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.json.JSONArray;
import org.json.JSONException;
import org.qi4j.api.entity.EntityReference;
import org.qi4j.spi.entity.ManyAssociationState;
import org.qi4j.spi.entitystore.EntityStoreException;
/**
* JSON implementation of ManyAssociationState.
* <p>Backed by a JSONArray.</p>
*/
public final class JSONManyAssociationState
implements ManyAssociationState
{
private final JSONEntityState entityState;
private final JSONArray references;
public JSONManyAssociationState( JSONEntityState entityState, JSONArray references )
{
this.entityState = entityState;
this.references = references;
}
@Override
public int count()
{
return references.length();
}
@Override
public boolean contains( EntityReference entityReference )
{
return indexOfReference( entityReference.identity() ) != -1;
}
@Override
public boolean add( int idx, EntityReference entityReference )
{
try
{
if( indexOfReference( entityReference.identity() ) != -1 )
{
return false;
}
entityState.cloneStateIfGlobalStateLoaded();
insertReference( idx, entityReference.identity() );
entityState.markUpdated();
return true;
}
catch( JSONException e )
{
throw new EntityStoreException( e );
}
}
@Override
public boolean remove( EntityReference entityReference )
{
int refIndex = indexOfReference( entityReference.identity() );
if( refIndex != -1 )
{
entityState.cloneStateIfGlobalStateLoaded();
references.remove( refIndex );
entityState.markUpdated();
return true;
}
return false;
}
@Override
public EntityReference get( int i )
{
try
{
return new EntityReference( references.getString( i ) );
}
catch( JSONException e )
{
throw new EntityStoreException( e );
}
}
@Override
public Iterator<EntityReference> iterator()
{
return new Iterator<EntityReference>()
{
private int idx = 0;
@Override
public boolean hasNext()
{
return idx < references.length();
}
@Override
public EntityReference next()
{
try
{
EntityReference ref = new EntityReference( references.getString( idx ) );
idx++;
return ref;
}
catch( JSONException e )
{
throw new NoSuchElementException();
}
}
@Override
public void remove()
{
throw new UnsupportedOperationException( "remove() is not supported on ManyAssociation iterators." );
}
};
}
@Override
public String toString()
{
return references.toString();
}
private int indexOfReference( Object item )
{
for( int idx = 0; idx < references.length(); idx++ )
{
if( item.equals( references.opt( idx ) ) )
{
return idx;
}
}
return -1;
}
private void insertReference( int insert, Object item )
throws JSONException
{
if( insert < 0 || insert > references.length() )
{
throw new JSONException( "JSONArray[" + insert + "] is out of bounds." );
}
if( insert == references.length() )
{
// append
references.put( item );
}
else
{
// insert (copy/insert/apply)
JSONArray output = new JSONArray();
for( int idx = 0; idx < references.length(); idx++ )
{
if( idx == insert )
{
output.put( item );
}
output.put( references.opt( idx ) );
}
for( int idx = 0; idx < output.length(); idx++ )
{
references.put( idx, output.opt( idx ) );
}
}
}
}