content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 com.datastax.oss.driver.internal.osgi.service.graph;
  
  import static com.datastax.dse.driver.api.core.graph.DseGraph.g;
  import static org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.__.unfold;
  
  import com.datastax.dse.driver.api.core.graph.FluentGraphStatement;
  import com.datastax.dse.driver.api.core.graph.GraphNode;
  import com.datastax.dse.driver.api.core.graph.ScriptGraphStatement;
  import com.datastax.oss.driver.api.core.CqlIdentifier;
  import com.datastax.oss.driver.api.core.CqlSession;
  import com.datastax.oss.driver.api.osgi.service.MailboxException;
  import com.datastax.oss.driver.api.osgi.service.MailboxMessage;
  import com.datastax.oss.driver.api.osgi.service.graph.GraphMailboxService;
  import com.datastax.oss.driver.internal.osgi.service.MailboxServiceImpl;
  import java.time.Instant;
  import java.util.stream.Collectors;
  
  public class GraphMailboxServiceImpl extends MailboxServiceImpl implements GraphMailboxService {
  
    private final String graphName;
  
    public GraphMailboxServiceImpl(CqlSession session, CqlIdentifier keyspace, String graphName) {
      super(session, keyspace);
      this.graphName = graphName;
    }
  
    @Override
    protected void createSchema() {
      super.createSchema();
      session.execute(
          ScriptGraphStatement.newInstance(
                  String.format("system.graph('%s').ifExists().drop()", graphName))
              .setSystemQuery(true),
          ScriptGraphStatement.SYNC);
      session.execute(
          ScriptGraphStatement.newInstance(
                  String.format("system.graph('%s').ifNotExists().coreEngine().create()", graphName))
              .setSystemQuery(true),
          ScriptGraphStatement.SYNC);
      session.execute(
          ScriptGraphStatement.newInstance(
              "schema.vertexLabel('message')"
                  + ".partitionBy('recipient', Text)"
                  + ".clusterBy('timestamp', Timestamp)"
                  + ".property('sender', Text)"
                  + ".property('body', Text)"
                  + ".create();"));
    }
  
    @Override
    public Iterable<MailboxMessage> getGraphMessages(String recipient) throws MailboxException {
      FluentGraphStatement statement =
          FluentGraphStatement.newInstance(
              g.V().hasLabel("message").has("recipient", recipient).valueMap().by(unfold()));
      try {
        return session.execute(statement).all().stream()
            .map(GraphNode::asMap)
            .map(
                vertex -> {
                  Instant timestamp = (Instant) vertex.get("timestamp");
                  String sender = (String) vertex.get("sender");
                  String body = (String) vertex.get("body");
                  return new MailboxMessage(recipient, timestamp, sender, body);
                })
            .collect(Collectors.toList());
      } catch (Exception e) {
        throw new MailboxException(e);
      }
    }
  
    @Override
    public void sendGraphMessage(MailboxMessage message) throws MailboxException {
      FluentGraphStatement insertVertex =
          FluentGraphStatement.newInstance(
              g.addV("message")
                  .property("recipient", message.getRecipient())
                  .property("timestamp", message.getTimestamp())
                  .property("sender", message.getSender())
                  .property("body", message.getBody()));
      try {
        session.execute(insertVertex);
      } catch (Exception e) {
        throw new MailboxException(e);
      }
    }
  }
  