package com.buschmais.xo.impl;
import com.buschmais.xo.api.XOException;
import com.buschmais.xo.spi.datastore.DatastorePropertyManager;
import com.buschmais.xo.spi.datastore.DatastoreRelationMetadata;
import com.buschmais.xo.spi.metadata.method.*;
import com.buschmais.xo.spi.metadata.type.RelationTypeMetadata;
import java.util.Iterator;
/**
* Contains methods for reading and creating relationships specified by the given metadata.
* <p/>
* <p>For each provided method the direction of the relationships is handled transparently for the caller.</p>
*/
public class EntityPropertyManager<Entity, Relation> extends AbstractPropertyManager<Entity, Entity, Relation> {
/**
* Constructor.
*
* @param sessionContext The {@link SessionContext}.
*/
public EntityPropertyManager(SessionContext<?, Entity, ?, ?, ?, Relation, ?, ?> sessionContext) {
super(sessionContext);
}
@Override
public void setProperty(Entity entity, PrimitivePropertyMethodMetadata metadata, Object value) {
SessionContext<?, Entity, ?, ?, ?, Relation, ?, ?> sessionContext = getSessionContext();
sessionContext.getDatastoreSession().getDatastorePropertyManager().setEntityProperty(entity, metadata, value);
sessionContext.getEntityInstanceManager().updateInstance(entity);
}
@Override
public Object getProperty(Entity entity, PrimitivePropertyMethodMetadata metadata) {
return getSessionContext().getDatastoreSession().getDatastorePropertyManager().getEntityProperty(entity, metadata);
}
@Override
public boolean hasProperty(Entity entity, PrimitivePropertyMethodMetadata metadata) {
return getSessionContext().getDatastoreSession().getDatastorePropertyManager().hasEntityProperty(entity, metadata);
}
@Override
public void removeProperty(Entity entity, PrimitivePropertyMethodMetadata metadata) {
SessionContext<?, Entity, ?, ?, ?, Relation, ?, ?> sessionContext = getSessionContext();
sessionContext.getDatastoreSession().getDatastorePropertyManager().removeEntityProperty(entity, metadata);
sessionContext.getEntityInstanceManager().updateInstance(entity);
}
public <T> T createEntityReference(Entity sourceEntity, AbstractRelationPropertyMethodMetadata<?> metadata, Object target) {
AbstractInstanceManager<?, Entity> instanceManager = getSessionContext().getEntityInstanceManager();
Entity targetEntity = target != null ? instanceManager.getDatastoreType(target) : null;
Relation relation = createRelation(sourceEntity, metadata, targetEntity, null);
return relation != null ? (T) instanceManager.updateInstance(getReferencedEntity(relation, metadata.getDirection())) : null;
}
public <T> T createRelationReference(Entity sourceEntity, AbstractRelationPropertyMethodMetadata<?> fromProperty, Object target, AbstractRelationPropertyMethodMetadata<?> toProperty) {
SessionContext<?, Entity, ?, ?, ?, Relation, ?, ?> sessionContext = getSessionContext();
AbstractInstanceManager<?, Entity> entityInstanceManager = sessionContext.getEntityInstanceManager();
if (target != null) {
Entity targetEntity = entityInstanceManager.getDatastoreType(target);
Relation relation = createRelation(sourceEntity, fromProperty, targetEntity, toProperty);
entityInstanceManager.updateInstance(targetEntity);
T instance = sessionContext.getRelationInstanceManager().createInstance(relation);
return instance;
}
return null;
}
public Object getEntityReference(Entity entity, EntityReferencePropertyMethodMetadata metadata) {
Relation singleRelation = getSingleRelation(entity, metadata.getRelationshipMetadata(), metadata.getDirection());
if (singleRelation != null) {
Entity target = getReferencedEntity(singleRelation, metadata.getDirection());
return getSessionContext().getEntityInstanceManager().readInstance(target);
}
return null;
}
public Iterator<Entity> getEntityCollection(Entity entity, final EntityCollectionPropertyMethodMetadata<?> metadata) {
Iterable<Relation> relations = getSessionContext().getDatastoreSession().getDatastorePropertyManager().getRelations(entity, metadata.getRelationshipMetadata(), metadata.getDirection());
final Iterator<Relation> iterator = relations.iterator();
return new Iterator<Entity>() {
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public Entity next() {
Relation next = iterator.next();
return getReferencedEntity(next, metadata.getDirection());
}
@Override
public void remove() {
}
};
}
public Object getRelationReference(Entity entity, RelationReferencePropertyMethodMetadata<?> metadata) {
Relation singleRelation = getSingleRelation(entity, metadata.getRelationshipMetadata(), metadata.getDirection());
if (singleRelation != null) {
return getSessionContext().getRelationInstanceManager().readInstance(singleRelation);
}
return null;
}
public Iterator<Relation> getRelationCollection(Entity entity, RelationCollectionPropertyMethodMetadata<?> metadata) {
Iterable<Relation> relations = getSessionContext().getDatastoreSession().getDatastorePropertyManager().getRelations(entity, metadata.getRelationshipMetadata(), metadata.getDirection());
return relations.iterator();
}
public void removeEntityReferences(Entity entity, EntityCollectionPropertyMethodMetadata metadata) {
Iterable<Relation> relations = getSessionContext().getDatastoreSession().getDatastorePropertyManager().getRelations(entity, metadata.getRelationshipMetadata(), metadata.getDirection());
for (Relation relation : relations) {
removeRelation(entity, relation, metadata);
}
}
public boolean removeEntityReference(Entity entity, EntityCollectionPropertyMethodMetadata<?> metadata, Object target) {
Iterable<Relation> relations = getSessionContext().getDatastoreSession().getDatastorePropertyManager().getRelations(entity, metadata.getRelationshipMetadata(), metadata.getDirection());
Entity targetEntity = getSessionContext().getEntityInstanceManager().getDatastoreType(target);
for (Relation relation : relations) {
Entity referencedEntity = getReferencedEntity(relation, metadata.getDirection());
if (referencedEntity.equals(targetEntity)) {
removeRelation(entity, relation, metadata);
return true;
}
}
return false;
}
private void removeRelation(Entity source, Relation relation, AbstractRelationPropertyMethodMetadata<?> metadata) {
SessionContext<?, Entity, ?, ?, ?, Relation, ?, ?> sessionContext = getSessionContext();
DatastorePropertyManager<Entity, Relation, ?, ? extends DatastoreRelationMetadata<?>> datastorePropertyManager = sessionContext.getDatastoreSession().getDatastorePropertyManager();
AbstractInstanceManager<?, Entity> entityInstanceManager = sessionContext.getEntityInstanceManager();
entityInstanceManager.updateInstance(source);
entityInstanceManager.updateInstance(getReferencedEntity(relation, metadata.getDirection()));
datastorePropertyManager.deleteRelation(relation);
AbstractInstanceManager<?, Relation> relationInstanceManager = getSessionContext().getRelationInstanceManager();
if (metadata.getRelationshipMetadata().getAnnotatedType() != null) {
Object instance = relationInstanceManager.readInstance(relation);
relationInstanceManager.removeInstance(instance);
relationInstanceManager.closeInstance(instance);
}
}
private Entity getReferencedEntity(Relation relation, RelationTypeMetadata.Direction direction) {
DatastorePropertyManager<Entity, Relation, ?, ? extends DatastoreRelationMetadata<?>> datastorePropertyManager = getSessionContext().getDatastoreSession().getDatastorePropertyManager();
switch (direction) {
case FROM:
return datastorePropertyManager.getTo(relation);
case TO:
return datastorePropertyManager.getFrom(relation);
default:
throw new XOException("Unsupported direction: " + direction);
}
}
private Relation createRelation(Entity sourceEntity, AbstractRelationPropertyMethodMetadata<?> fromProperty, Entity targetEntity, AbstractRelationPropertyMethodMetadata<?> toProperty) {
Relation relation;
if (fromProperty instanceof EntityReferencePropertyMethodMetadata || fromProperty instanceof RelationReferencePropertyMethodMetadata) {
relation = createSingleReference(sourceEntity, fromProperty, targetEntity);
} else if (toProperty instanceof EntityReferencePropertyMethodMetadata || toProperty instanceof RelationReferencePropertyMethodMetadata) {
relation = createSingleReference(targetEntity, toProperty, sourceEntity);
} else if (fromProperty instanceof EntityCollectionPropertyMethodMetadata || fromProperty instanceof RelationCollectionPropertyMethodMetadata) {
relation = createReference(sourceEntity, fromProperty.getRelationshipMetadata(), fromProperty.getDirection(), targetEntity);
} else {
throw new XOException("Unsupported relation type " + fromProperty.getClass().getName());
}
return relation;
}
private Relation createSingleReference(Entity sourceEntity, AbstractRelationPropertyMethodMetadata<?> metadata, Entity targetEntity) {
DatastorePropertyManager<Entity, Relation, ?, ?> datastorePropertyManager = getSessionContext().getDatastoreSession().getDatastorePropertyManager();
if (datastorePropertyManager.hasSingleRelation(sourceEntity, metadata.getRelationshipMetadata(), metadata.getDirection())) {
Relation relation = datastorePropertyManager.getSingleRelation(sourceEntity, metadata.getRelationshipMetadata(), metadata.getDirection());
removeRelation(sourceEntity, relation, metadata);
}
return targetEntity != null ? datastorePropertyManager.createRelation(sourceEntity, metadata.getRelationshipMetadata(), metadata.getDirection(), targetEntity) : null;
}
private Relation createReference(Entity sourceEntity, RelationTypeMetadata metadata, RelationTypeMetadata.Direction direction, Entity targetEntity) {
DatastorePropertyManager<Entity, Relation, ?, ?> datastorePropertyManager = getSessionContext().getDatastoreSession().getDatastorePropertyManager();
return datastorePropertyManager.createRelation(sourceEntity, metadata, direction, targetEntity);
}
}