package er.neo4jadaptor.ersatz.neo4j;
import java.util.HashMap;
import java.util.Map;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.PropertyContainer;
import org.neo4j.graphdb.Relationship;
import com.webobjects.eoaccess.EOAttribute;
import com.webobjects.eoaccess.EOEntity;
import com.webobjects.eoaccess.EORelationship;
import er.neo4jadaptor.ersatz.Ersatz;
/**
* Ersatz stored using Neo4J {@link PropertyContainer}.
*
* @author Jedrzej Sobanski
*/
public abstract class Neo4JErsatz extends Ersatz {
protected final EOEntity entity;
private final PropertyContainer pc;
// source attribute name -> relationship
private final Map<String, EORelationship> foreignKeys = new HashMap<String, EORelationship>();
/**
* Create ersatz using values stored in the given property container.
*
* @param entity entity that the property container contains record for
* @param pc property container to read record values from
* @return ersatz for a record stored in property container
*/
public static Neo4JErsatz create(EOEntity entity, PropertyContainer pc) {
if (pc instanceof Node) {
return new Neo4JNodeErsatz(entity, (Node) pc);
} else if (pc instanceof Relationship) {
return new Neo4JRelationshipErsatz(entity, (Relationship) pc);
} else {
throw new IllegalArgumentException("Property container " + pc + " is not supported/known");
}
}
protected Neo4JErsatz(EOEntity entity, PropertyContainer pc) {
this.entity = entity;
this.pc = pc;
for (EORelationship rel : entity.relationships()) {
if (! rel.isCompound() && ! rel.isToMany()) {
if (rel.sourceAttributes().size() != 1) {
throw new IllegalArgumentException();
} else {
EOAttribute att = rel.sourceAttributes().get(0);
foreignKeys.put(att.name(), rel);
}
}
}
}
public PropertyContainer getPropertyContainer() {
return pc;
}
@Override
public Iterable<EOAttribute> attributes() {
return entity.attributes();
}
private boolean isForeignKey(EOAttribute att) {
return foreignKeys.containsKey(att.name());
}
/**
* Gets ID of an object referenced by the given foreign key
*
* @param rel foreign key attribute
* @return referenced object ID
*/
protected abstract Number getForeignKeyValue(EORelationship rel);
/**
* Sets relationship value.
*
* @param rel relationship to set value for
* @param val ID of an object referenced by the relationship
*/
protected abstract void setForeignKeyValue(EORelationship rel, Number val);
@Override
public Object get(EOAttribute att) {
if (isForeignKey(att)) {
EORelationship rel = foreignKeys.get(att.name());
return getForeignKeyValue(rel);
} else {
return getAttribute(pc, att);
}
}
@Override
public void put(EOAttribute att, Object value) {
if (isForeignKey(att)) {
EORelationship rel = foreignKeys.get(att.name());
setForeignKeyValue(rel, (Number) value);
} else {
setAttribute(pc, att, value);
}
}
/**
* Gets EO attribute value from a property container.
*
* @param container
* @param att
* @return EO attribute value
*/
public static Object getAttribute(PropertyContainer container, EOAttribute att) {
Object libraryValue = container.getProperty(att.name(), null); // if property is not set then use null as default
return Neo4JTranslator.instance.toNeutralValue(libraryValue, att);
}
protected static void setAttribute(PropertyContainer pc, EOAttribute att, Object value ) {
Object libraryValue = Neo4JTranslator.instance.fromNeutralValue(value, att);
if (libraryValue != null) {
pc.setProperty(att.name(), libraryValue);
} else {
pc.removeProperty(att.name());
}
}
@Override
public void remove(EOAttribute att) {
pc.removeProperty(att.name());
}
}