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A driver for DataStax Enterprise (DSE) and Apache Cassandra 1.2+ clusters that works exclusively with the Cassandra Query Language version 3 (CQL3) and Cassandra's binary protocol, supporting DSE-specific features such as geospatial types, DSE Graph and DSE authentication.

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/*
 * Copyright DataStax, Inc.
 *
 * This software can be used solely with DataStax Enterprise. Please consult the license at
 * http://www.datastax.com/terms/datastax-dse-driver-license-terms
 */
package com.datastax.driver.dse.graph;

import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
import com.google.common.collect.Multimap;
import com.google.common.collect.MultimapBuilder;
import com.google.common.collect.SetMultimap;
import java.io.IOException;
import java.util.Iterator;

class DefaultVertexPropertyDeserializer extends StdDeserializer {

  private static final String ID = "id";
  private static final String VALUE = "value";
  private static final String PROPERTIES = "properties";

  DefaultVertexPropertyDeserializer() {
    super(VertexProperty.class);
  }

  @Override
  public DefaultVertexProperty deserialize(JsonParser parser, DeserializationContext ctx)
      throws IOException {
    if (!(parser instanceof PropertyGraphNodeParser))
      throw new JsonParseException(
          parser,
          "Cannot deserialize property if parser is not instance of PropertyGraphNodeParser");
    PropertyGraphNodeParser propertyGraphNodeParser = (PropertyGraphNodeParser) parser;
    String name = propertyGraphNodeParser.propertyName;
    if (name == null)
      throw new JsonParseException(parser, "Cannot deserialize property with null name");
    Element parent = propertyGraphNodeParser.parent;
    if (parent == null)
      throw new JsonParseException(parser, "Cannot deserialize property with null parent");
    if (!(parent instanceof Vertex))
      throw new JsonParseException(parser, "Vertex property parent is not a Vertex: " + parent);
    JsonNode jacksonNode = parser.readValueAsTree();
    ObjectMapper objectMapper = (ObjectMapper) parser.getCodec();
    DefaultGraphNode propertyNode = new DefaultGraphNode(jacksonNode, objectMapper);
    DefaultVertexProperty vertexProperty = new DefaultVertexProperty();
    vertexProperty.id = propertyNode.get(ID);
    vertexProperty.label = name;
    vertexProperty.value = propertyNode.get(VALUE);
    vertexProperty.parent = (Vertex) parent;
    vertexProperty.properties = metaProperties(propertyNode, objectMapper, vertexProperty);
    return vertexProperty;
  }

  private Multimap metaProperties(
      DefaultGraphNode node, ObjectMapper objectMapper, DefaultVertexProperty vertexProperty) {
    if (node == null) return null;
    GraphNode metaProperties = node.get(PROPERTIES);
    if (metaProperties == null) return null;
    SetMultimap metaPropertiesMap =
        MultimapBuilder.linkedHashKeys().linkedHashSetValues().build();
    Iterator it = metaProperties.fieldNames();
    while (it.hasNext()) {
      String metaPropKey = it.next();
      GraphNode metaPropValue = metaProperties.get(metaPropKey);
      metaPropertiesMap.put(
          metaPropKey,
          new PropertyGraphNode(
              ((DefaultGraphNode) metaPropValue).delegate,
              objectMapper,
              metaPropKey,
              vertexProperty));
    }
    return metaPropertiesMap;
  }
}