/*
 * 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 org.apache.beam.sdk.io.jdbc;

import static org.junit.Assert.assertTrue;

import java.io.PrintWriter;
import java.io.Serializable;
import java.io.StringWriter;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Collections;
import javax.sql.DataSource;
import org.apache.beam.sdk.coders.KvCoder;
import org.apache.beam.sdk.coders.SerializableCoder;
import org.apache.beam.sdk.coders.StringUtf8Coder;
import org.apache.beam.sdk.coders.VarIntCoder;
import org.apache.beam.sdk.io.common.DatabaseTestHelper;
import org.apache.beam.sdk.io.common.TestRow;
import org.apache.beam.sdk.testing.ExpectedLogs;
import org.apache.beam.sdk.testing.PAssert;
import org.apache.beam.sdk.testing.TestPipeline;
import org.apache.beam.sdk.transforms.Count;
import org.apache.beam.sdk.transforms.Create;
import org.apache.beam.sdk.values.KV;
import org.apache.beam.sdk.values.PCollection;
import org.apache.derby.drda.NetworkServerControl;
import org.apache.derby.jdbc.ClientDataSource;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Rule;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/** Test on the JdbcIO. */
public class JdbcIOTest implements Serializable {

  private static final Logger LOG = LoggerFactory.getLogger(JdbcIOTest.class);
  public static final int EXPECTED_ROW_COUNT = 1000;
  public static final String BACKOFF_TABLE = "UT_WRITE_BACKOFF";

  private static NetworkServerControl derbyServer;
  private static ClientDataSource dataSource;

  private static int port;
  private static String readTableName;

  @Rule public final transient TestPipeline pipeline = TestPipeline.create();

  @Rule public final transient ExpectedLogs expectedLogs = ExpectedLogs.none(JdbcIO.class);

  @BeforeClass
  public static void startDatabase() throws Exception {
    ServerSocket socket = new ServerSocket(0);
    port = socket.getLocalPort();
    socket.close();

    LOG.info("Starting Derby database on {}", port);

    // by default, derby uses a lock timeout of 60 seconds. In order to speed up the test
    // and detect the lock faster, we decrease this timeout
    System.setProperty("derby.locks.waitTimeout", "2");
    System.setProperty("derby.stream.error.file", "target/derby.log");

    derbyServer = new NetworkServerControl(InetAddress.getByName("localhost"), port);
    StringWriter out = new StringWriter();
    derbyServer.start(new PrintWriter(out));
    boolean started = false;
    int count = 0;
    // Use two different methods to detect when server is started:
    // 1) Check the server stdout for the "started" string
    // 2) wait up to 15 seconds for the derby server to start based on a ping
    // on faster machines and networks, this may return very quick, but on slower
    // networks where the DNS lookups are slow, this may take a little time
    while (!started && count < 30) {
      if (out.toString().contains("started")) {
        started = true;
      } else {
        count++;
        Thread.sleep(500);
        try {
          derbyServer.ping();
          started = true;
        } catch (Throwable t) {
          // ignore, still trying to start
        }
      }
    }

    dataSource = new ClientDataSource();
    dataSource.setCreateDatabase("create");
    dataSource.setDatabaseName("target/beam");
    dataSource.setServerName("localhost");
    dataSource.setPortNumber(port);

    readTableName = DatabaseTestHelper.getTestTableName("UT_READ");

    DatabaseTestHelper.createTable(dataSource, readTableName);
    addInitialData(dataSource, readTableName);
  }

  @AfterClass
  public static void shutDownDatabase() throws Exception {
    try {
      DatabaseTestHelper.deleteTable(dataSource, readTableName);
    } finally {
      if (derbyServer != null) {
        derbyServer.shutdown();
      }
    }
  }

  @Test
  public void testDataSourceConfigurationDataSource() throws Exception {
    JdbcIO.DataSourceConfiguration config = JdbcIO.DataSourceConfiguration.create(dataSource);
    try (Connection conn = config.buildDatasource().getConnection()) {
      assertTrue(conn.isValid(0));
    }
  }

  @Test
  public void testDataSourceConfigurationDriverAndUrl() throws Exception {
    JdbcIO.DataSourceConfiguration config =
        JdbcIO.DataSourceConfiguration.create(
            "org.apache.derby.jdbc.ClientDriver",
            "jdbc:derby://localhost:" + port + "/target/beam");
    try (Connection conn = config.buildDatasource().getConnection()) {
      assertTrue(conn.isValid(0));
    }
  }

  @Test
  public void testDataSourceConfigurationUsernameAndPassword() throws Exception {
    String username = "sa";
    String password = "sa";
    JdbcIO.DataSourceConfiguration config =
        JdbcIO.DataSourceConfiguration.create(
                "org.apache.derby.jdbc.ClientDriver",
                "jdbc:derby://localhost:" + port + "/target/beam")
            .withUsername(username)
            .withPassword(password);
    try (Connection conn = config.buildDatasource().getConnection()) {
      assertTrue(conn.isValid(0));
    }
  }

  @Test
  public void testDataSourceConfigurationNullPassword() throws Exception {
    String username = "sa";
    String password = null;
    JdbcIO.DataSourceConfiguration config =
        JdbcIO.DataSourceConfiguration.create(
                "org.apache.derby.jdbc.ClientDriver",
                "jdbc:derby://localhost:" + port + "/target/beam")
            .withUsername(username)
            .withPassword(password);
    try (Connection conn = config.buildDatasource().getConnection()) {
      assertTrue(conn.isValid(0));
    }
  }

  @Test
  public void testDataSourceConfigurationNullUsernameAndPassword() throws Exception {
    String username = null;
    String password = null;
    JdbcIO.DataSourceConfiguration config =
        JdbcIO.DataSourceConfiguration.create(
                "org.apache.derby.jdbc.ClientDriver",
                "jdbc:derby://localhost:" + port + "/target/beam")
            .withUsername(username)
            .withPassword(password);
    try (Connection conn = config.buildDatasource().getConnection()) {
      assertTrue(conn.isValid(0));
    }
  }

  /** Create test data that is consistent with that generated by TestRow. */
  private static void addInitialData(DataSource dataSource, String tableName) throws SQLException {
    try (Connection connection = dataSource.getConnection()) {
      connection.setAutoCommit(false);
      try (PreparedStatement preparedStatement =
          connection.prepareStatement(String.format("insert into %s values (?,?)", tableName))) {
        for (int i = 0; i < EXPECTED_ROW_COUNT; i++) {
          preparedStatement.clearParameters();
          preparedStatement.setInt(1, i);
          preparedStatement.setString(2, TestRow.getNameForSeed(i));
          preparedStatement.executeUpdate();
        }
      }
      connection.commit();
    }
  }

  @Test
  public void testRead() throws Exception {
    PCollection<TestRow> rows =
        pipeline.apply(
            JdbcIO.<TestRow>read()
                .withFetchSize(12)
                .withDataSourceConfiguration(JdbcIO.DataSourceConfiguration.create(dataSource))
                .withQuery("select name,id from " + readTableName)
                .withRowMapper(new JdbcTestHelper.CreateTestRowOfNameAndId())
                .withCoder(SerializableCoder.of(TestRow.class)));

    PAssert.thatSingleton(rows.apply("Count All", Count.globally()))
        .isEqualTo((long) EXPECTED_ROW_COUNT);

    Iterable<TestRow> expectedValues = TestRow.getExpectedValues(0, EXPECTED_ROW_COUNT);
    PAssert.that(rows).containsInAnyOrder(expectedValues);

    pipeline.run();
  }

  @Test
  public void testReadWithSingleStringParameter() throws Exception {
    PCollection<TestRow> rows =
        pipeline.apply(
            JdbcIO.<TestRow>read()
                .withDataSourceConfiguration(JdbcIO.DataSourceConfiguration.create(dataSource))
                .withQuery(String.format("select name,id from %s where name = ?", readTableName))
                .withStatementPreparator(
                    preparedStatement -> preparedStatement.setString(1, TestRow.getNameForSeed(1)))
                .withRowMapper(new JdbcTestHelper.CreateTestRowOfNameAndId())
                .withCoder(SerializableCoder.of(TestRow.class)));

    PAssert.thatSingleton(rows.apply("Count All", Count.globally())).isEqualTo(1L);

    Iterable<TestRow> expectedValues = Collections.singletonList(TestRow.fromSeed(1));
    PAssert.that(rows).containsInAnyOrder(expectedValues);

    pipeline.run();
  }

  @Test
  public void testWrite() throws Exception {
    final long rowsToAdd = 1000L;

    String tableName = DatabaseTestHelper.getTestTableName("UT_WRITE");
    DatabaseTestHelper.createTable(dataSource, tableName);
    try {
      ArrayList<KV<Integer, String>> data = new ArrayList<>();
      for (int i = 0; i < rowsToAdd; i++) {
        KV<Integer, String> kv = KV.of(i, "Test");
        data.add(kv);
      }
      pipeline
          .apply(Create.of(data))
          .apply(
              JdbcIO.<KV<Integer, String>>write()
                  .withDataSourceConfiguration(
                      JdbcIO.DataSourceConfiguration.create(
                          "org.apache.derby.jdbc.ClientDriver",
                          "jdbc:derby://localhost:" + port + "/target/beam"))
                  .withStatement(String.format("insert into %s values(?, ?)", tableName))
                  .withBatchSize(10L)
                  .withPreparedStatementSetter(
                      (element, statement) -> {
                        statement.setInt(1, element.getKey());
                        statement.setString(2, element.getValue());
                      }));

      pipeline.run();

      try (Connection connection = dataSource.getConnection()) {
        try (Statement statement = connection.createStatement()) {
          try (ResultSet resultSet = statement.executeQuery("select count(*) from " + tableName)) {
            resultSet.next();
            int count = resultSet.getInt(1);

            Assert.assertEquals(EXPECTED_ROW_COUNT, count);
          }
        }
      }
    } finally {
      DatabaseTestHelper.deleteTable(dataSource, tableName);
    }
  }

  @Test
  public void testWriteWithBackoff() throws Exception {
    String tableName = DatabaseTestHelper.getTestTableName("UT_WRITE_BACKOFF");
    DatabaseTestHelper.createTable(dataSource, tableName);

    // lock table
    Connection connection = dataSource.getConnection();
    Statement lockStatement = connection.createStatement();
    lockStatement.execute("ALTER TABLE " + tableName + " LOCKSIZE TABLE");
    lockStatement.execute("LOCK TABLE " + tableName + " IN EXCLUSIVE MODE");

    // start a first transaction
    connection.setAutoCommit(false);
    PreparedStatement insertStatement =
        connection.prepareStatement("insert into " + tableName + " values(?, ?)");
    insertStatement.setInt(1, 1);
    insertStatement.setString(2, "TEST");
    insertStatement.execute();

    // try to write to this table
    pipeline
        .apply(Create.of(Collections.singletonList(KV.of(1, "TEST"))))
        .apply(
            JdbcIO.<KV<Integer, String>>write()
                .withDataSourceConfiguration(
                    JdbcIO.DataSourceConfiguration.create(
                        "org.apache.derby.jdbc.ClientDriver",
                        "jdbc:derby://localhost:" + port + "/target/beam"))
                .withStatement(String.format("insert into %s values(?, ?)", tableName))
                .withRetryStrategy(
                    (JdbcIO.RetryStrategy)
                        e -> {
                          return "XJ208"
                              .equals(e.getSQLState()); // we fake a deadlock with a lock here
                        })
                .withPreparedStatementSetter(
                    (element, statement) -> {
                      statement.setInt(1, element.getKey());
                      statement.setString(2, element.getValue());
                    }));

    // starting a thread to perform the commit later, while the pipeline is running into the backoff
    Thread commitThread =
        new Thread(
            () -> {
              try {
                Thread.sleep(10000);
                connection.commit();
              } catch (Exception e) {
                // nothing to do
              }
            });
    commitThread.start();
    pipeline.run();
    commitThread.join();

    // we verify the the backoff has been called thanks to the log message
    expectedLogs.verifyWarn("Deadlock detected, retrying");

    try (Connection readConnection = dataSource.getConnection()) {
      try (Statement statement = readConnection.createStatement()) {
        try (ResultSet resultSet = statement.executeQuery("select count(*) from " + tableName)) {
          resultSet.next();
          int count = resultSet.getInt(1);
          // here we have the record inserted by the first transaction (by hand), and a second one
          // inserted by the pipeline
          Assert.assertEquals(2, count);
        }
      }
    }
  }

  @After
  public void tearDown() {
    try {
      DatabaseTestHelper.deleteTable(dataSource, BACKOFF_TABLE);
    } catch (Exception e) {
      // nothing to do
    }
  }

  @Test
  public void testWriteWithEmptyPCollection() throws Exception {
    pipeline
        .apply(Create.empty(KvCoder.of(VarIntCoder.of(), StringUtf8Coder.of())))
        .apply(
            JdbcIO.<KV<Integer, String>>write()
                .withDataSourceConfiguration(
                    JdbcIO.DataSourceConfiguration.create(
                        "org.apache.derby.jdbc.ClientDriver",
                        "jdbc:derby://localhost:" + port + "/target/beam"))
                .withStatement("insert into BEAM values(?, ?)")
                .withPreparedStatementSetter(
                    (element, statement) -> {
                      statement.setInt(1, element.getKey());
                      statement.setString(2, element.getValue());
                    }));

    pipeline.run();
  }
}
