package com.dooapp.gaedo.blueprints;
import com.dooapp.gaedo.blueprints.transformers.LiteralTransformer;
import com.dooapp.gaedo.blueprints.transformers.Literals;
import com.dooapp.gaedo.properties.Property;
import com.tinkerpop.blueprints.pgm.CloseableSequence;
import com.tinkerpop.blueprints.pgm.Index;
import com.tinkerpop.blueprints.pgm.IndexableGraph;
import com.tinkerpop.blueprints.pgm.Vertex;
public class GraphUtils {
/**
* Helper function locating first matching vertex with the given property value
* @param graph
* @param property
* @param object
* @return
*/
public static Vertex locateVertex(IndexableGraph graph, String property, Object value) {
CloseableSequence<Vertex> matching = graph.getIndex(Index.VERTICES, Vertex.class).get(property, value);
if(matching.hasNext()) {
return matching.next();
} else {
return null;
}
}
public static Vertex locateVertex(IndexableGraph graph, Properties p, Object value) {
return locateVertex(graph, p.name(), value);
}
/**
* Generate edge name from property infos
* @param p source property
* @return an edge name (by default property container class name + "." + property name
*/
public static String getEdgeNameFor(Property p) {
return p.getDeclaringClass().getSimpleName()+"."+p.getName();
}
/**
* Create a vertex out of a basic object. if object is of a simple type, we'll use value as id. Elsewhere, we will generate an id for object
* @param database database in which vertex will be stored
* @param value
* @return
*/
public static Vertex getVertexForBasicObject(IndexableGraph database, Object value) {
Vertex returned = null;
// Now distinct behaviour between known objects and unknown ones
Class<? extends Object> valueClass = value.getClass();
if(Literals.containsKey(valueClass)) {
LiteralTransformer transformer = Literals.get(valueClass);
returned = transformer.getVertexFor(database, valueClass.cast(value));
} else {
throw new ObjectIsNotARealLiteralException(value, valueClass);
// TODO do not forget to set id property
}
returned.setProperty(Properties.type.name(), valueClass.getName());
return returned;
}
/**
* Create an object instance from a managed vertice compatible with this service contained class
* @param key vertex containing object id
* @return a fresh instance, with only id set
*/
public static Object createInstance(Vertex key) {
String effectiveType = key.getProperty(Properties.type.name()).toString();
try {
Class effectiveClass = Class.forName(effectiveType);
if(Literals.containsKey(effectiveClass)) {
LiteralTransformer transformer = Literals.get(effectiveClass);
return transformer.loadObject(effectiveClass, key);
} else {
return effectiveClass.newInstance();
}
} catch(Exception e) {
throw new UnableToCreateException(effectiveType, e);
}
}
/**
* Get an id for any object, provided one property can be used to define an id on it
* @param database source database
* @param object used object
* @param idProperty id property
* @return a composite id made of id container class, and the result of {@link LiteralTransformer#getVertexId(com.tinkerpop.blueprints.pgm.Graph, Object)}
*/
public static Object getIdVertexId(IndexableGraph database, Object object, Property idProperty) {
Object objectId = idProperty.get(object);
return idProperty.getDeclaringClass().getCanonicalName()+":"+Literals.get(objectId.getClass()).getVertexId(database, objectId);
}
}