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/*
 * Copyright 2019 The Vitess Authors.

 * Licensed 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 io.vitess.example;

import com.google.common.collect.ImmutableMap;
import com.google.common.primitives.UnsignedLong;

import io.vitess.client.Context;
import io.vitess.client.RpcClient;
import io.vitess.client.VTGateBlockingConnection;
import io.vitess.client.VTSession;
import io.vitess.client.cursor.Cursor;
import io.vitess.client.cursor.Row;
import io.vitess.client.grpc.GrpcClientFactory;
import io.vitess.proto.Query.ExecuteOptions;

import org.joda.time.Duration;
import org.joda.time.Instant;

import java.util.Map;
import java.util.Random;

/**
 * VitessClientExample.java is a sample for using the Vitess low-level Java Client.
 * 
 * Before running this, start up a local example cluster as described in the
 * examples/local/README.md file.
 */
public class VitessClientExample {

  public static void main(String[] args) {
    if (args.length != 1) {
      System.out.println("usage: VitessClientExample ");
      System.exit(1);
    }

    Context ctx = Context.getDefault().withDeadlineAfter(Duration.millis(5 * 1000));
    try (RpcClient client = new GrpcClientFactory()
        .create(ctx, args[0]); VTGateBlockingConnection conn = new VTGateBlockingConnection(
        client)) {
      VTSession session = new VTSession("@primary", ExecuteOptions.getDefaultInstance());
      // Insert some messages on random pages.
      System.out.println("Inserting into primary...");
      Random rand = new Random();
      for (int i = 0; i < 3; i++) {
        Instant timeCreated = Instant.now();
        Map bindVars = new ImmutableMap.Builder()
            .put("page", rand.nextInt(100) + 1)
            .put("time_created_ns", timeCreated.getMillis() * 1000000)
            .put("message", "V is for speed").build();

        conn.execute(ctx, "begin", null, session);
        conn.execute(ctx,
            "INSERT INTO messages (page,time_created_ns,message) VALUES (:page,:time_created_ns,"
                + ":message)",
            bindVars, session);
        conn.execute(ctx, "commit", null, session);
      }

      // Read it back from the primary.
      System.out.println("Reading from primary...");
      try (Cursor cursor = conn
          .execute(ctx, "SELECT page, time_created_ns, message FROM messages", null, session)) {
        Row row;
        while ((row = cursor.next()) != null) {
          UnsignedLong page = row.getULong("page");
          UnsignedLong timeCreated = row.getULong("time_created_ns");
          byte[] message = row.getBytes("message");
          System.out.format("(%s, %s, %s)\n", page, timeCreated, new String(message));
        }
      }
    } catch (Exception exc) {
      System.out.println("Vitess Java example failed.");
      System.out.println("Error Details:");
      exc.printStackTrace();
      System.exit(2);
    }
  }
}