/*
 * 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.drill;

import org.apache.drill.categories.SqlFunctionTest;
import org.apache.drill.common.types.TypeProtos;
import org.apache.drill.common.types.Types;
import org.apache.drill.exec.ExecConstants;
import org.apache.drill.exec.record.BatchSchema;
import org.apache.drill.exec.record.BatchSchemaBuilder;
import org.apache.drill.exec.record.metadata.SchemaBuilder;
import org.apache.drill.test.ClusterFixture;
import org.apache.drill.test.ClusterFixtureBuilder;
import org.apache.drill.test.ClusterTest;
import org.apache.drill.test.QueryBuilder;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.experimental.categories.Category;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

@Category(SqlFunctionTest.class)
public class TestUntypedNull extends ClusterTest {

  private static final TypeProtos.MajorType UNTYPED_NULL_TYPE = Types.optional(TypeProtos.MinorType.NULL);

  @BeforeClass
  public static void setup() throws Exception {
    ClusterFixtureBuilder builder = ClusterFixture.builder(dirTestWatcher);
    startCluster(builder);
  }

  @Test
  public void testSplitFunction() throws Exception {
    String query = "select split(n_name, ' ') [1] from cp.`tpch/nation.parquet`\n" +
      "where n_nationkey = -1 group by n_name order by n_name limit 10";
    QueryBuilder.QuerySummary summary = queryBuilder().sql(query).run();
    assertTrue(summary.succeeded());
    assertEquals(0, summary.recordCount());
  }

  @Test
  public void testWindowFunction() throws Exception {
    String query = "select row_number() over (partition by split(n_name, ' ') [1])\n" +
      "from cp.`tpch/nation.parquet` where n_nationkey = -1";
    QueryBuilder.QuerySummary summary = queryBuilder().sql(query).run();
    assertTrue(summary.succeeded());
    assertEquals(0, summary.recordCount());
  }

  @Test
  public void testUnion() throws Exception {
    String query = "select split(n_name, ' ') [1] from cp.`tpch/nation.parquet` where n_nationkey = -1 group by n_name\n" +
      "union\n" +
      "select split(n_name, ' ') [1] from cp.`tpch/nation.parquet` where n_nationkey = -1 group by n_name";
    QueryBuilder.QuerySummary summary = queryBuilder().sql(query).run();
    assertTrue(summary.succeeded());
    assertEquals(0, summary.recordCount());
  }

  @Test
  public void testParquetTableCreation() throws Exception {
    testTableCreation("parquet");
  }

  @Test
  public void testJsonTableCreation() throws Exception {
    testTableCreation("json");
  }

  @Test
  public void testCsvTableCreation() throws Exception {
    testTableCreation("csv");
  }


  private void testTableCreation(String format) throws Exception {
    String tableName = "table_" + format;
    try {
      client.alterSession(ExecConstants.OUTPUT_FORMAT_OPTION, format);
      String query = "create table dfs.tmp." + tableName + " as\n" +
          "select split(n_name, ' ') [1] from cp.`tpch/nation.parquet` where n_nationkey = -1 group by n_name";

      QueryBuilder.QuerySummary summary = queryBuilder().sql(query).run();

      assertTrue(summary.succeeded());
      assertEquals(1, summary.recordCount());
    } finally {
      client.resetSession(ExecConstants.OUTPUT_FORMAT_OPTION);
      queryBuilder().sql("drop table if exists dfs.tmp." + tableName).run();
    }
  }

  @Test
  public void testTypeAndMode() throws Exception {
    String query = "select\n" +
      "typeof(split(n_name, ' ') [1]),\n" +
      "drilltypeof(split(n_name, ' ') [1]),\n" +
      "sqltypeof(split(n_name, ' ') [1]),\n" +
      "modeof(split(n_name, ' ') [1])\n" +
      "from cp.`tpch/nation.parquet`\n" +
      "where n_nationkey = -1";
    QueryBuilder.QuerySummary summary = queryBuilder().sql(query).run();
    assertTrue(summary.succeeded());
    assertEquals(0, summary.recordCount());
  }

  @Test
  public void testCoalesceOnNotExistentColumns() throws Exception {
    String query = "select coalesce(unk1, unk2) as coal from cp.`tpch/nation.parquet` limit 5";
    SchemaBuilder schemaBuilder = new SchemaBuilder()
        .add("coal", UNTYPED_NULL_TYPE);
    BatchSchema expectedSchema = new BatchSchemaBuilder()
        .withSchemaBuilder(schemaBuilder)
        .build();

    testBuilder()
        .sqlQuery(query)
        .schemaBaseLine(expectedSchema)
        .go();

    testBuilder()
        .sqlQuery(query)
        .unOrdered()
        .baselineColumns("coal")
        .baselineValuesForSingleColumn(null, null, null, null, null)
        .go();
  }

  @Test
  public void testCoalesceOnNotExistentColumnsWithGroupBy() throws Exception {
    String query = "select coalesce(unk1, unk2) as coal from cp.`tpch/nation.parquet` group by 1";
    SchemaBuilder schemaBuilder = new SchemaBuilder()
        .add("coal", UNTYPED_NULL_TYPE);
    BatchSchema expectedSchema = new BatchSchemaBuilder()
        .withSchemaBuilder(schemaBuilder)
        .build();

    testBuilder()
      .sqlQuery(query)
        .schemaBaseLine(expectedSchema)
        .go();

    testBuilder()
        .sqlQuery(query)
        .unOrdered()
        .baselineColumns("coal")
        .baselineValuesForSingleColumn(new Object[] {null})
        .go();
  }

  @Test
  public void testCoalesceOnNotExistentColumnsWithOrderBy() throws Exception {
    String query = "select coalesce(unk1, unk2) as coal from cp.`tpch/nation.parquet` order by 1 limit 5";
    SchemaBuilder schemaBuilder = new SchemaBuilder()
        .add("coal", UNTYPED_NULL_TYPE);
    BatchSchema expectedSchema = new BatchSchemaBuilder()
        .withSchemaBuilder(schemaBuilder)
        .build();

    testBuilder()
        .sqlQuery(query)
        .schemaBaseLine(expectedSchema)
        .go();

    testBuilder()
        .sqlQuery(query)
        .unOrdered()
        .baselineColumns("coal")
        .baselineValuesForSingleColumn(null, null, null, null, null)
        .go();
  }

  @Test
  public void testCoalesceOnNotExistentColumnsWithCoalesceInWhereClause() throws Exception {
    String query = "select coalesce(unk1, unk2) as coal from cp.`tpch/nation.parquet` where coalesce(unk1, unk2) > 10";
    testBuilder()
        .sqlQuery(query)
        .unOrdered()
        .expectsNumRecords(0)
        .go();
  }

  @Test
  public void testCoalesceOnNotExistentColumnsWithCoalesceInHavingClause() throws Exception {
    String query = "select 1 from cp.`tpch/nation.parquet` group by n_name having count(coalesce(unk1, unk2)) > 10";
    testBuilder()
        .sqlQuery(query)
        .unOrdered()
        .expectsNumRecords(0)
        .go();
  }

  @Test
  public void testPartitionByCoalesceOnNotExistentColumns() throws Exception {
    String query =
        "select row_number() over (partition by coalesce(unk1, unk2)) as row_num from cp.`tpch/nation.parquet` limit 5";
    testBuilder()
        .sqlQuery(query)
        .unOrdered()
        .baselineColumns("row_num")
        .baselineValuesForSingleColumn(1L, 2L, 3L, 4L, 5L)
        .go();
  }

  @Test
  public void testCoalesceOnNotExistentColumnsInUDF() throws Exception {
    String query = "select substr(coalesce(unk1, unk2), 1, 2) as coal from cp.`tpch/nation.parquet` limit 5";
    testBuilder()
        .sqlQuery(query)
        .unOrdered()
        .baselineColumns("coal")
        .baselineValuesForSingleColumn(null, null, null, null, null)
        .go();
  }

  @Test
  public void testCoalesceOnNotExistentColumnsInUDF2() throws Exception {
    String query = "select abs(coalesce(unk1, unk2)) as coal from cp.`tpch/nation.parquet` limit 5";
    testBuilder()
        .sqlQuery(query)
        .unOrdered()
        .baselineColumns("coal")
        .baselineValuesForSingleColumn(null, null, null, null, null)
        .go();
  }

  @Test
  public void testValueIsNotReferencedOnUntypedNullHolderInstance() throws Exception {
    testBuilder()
        .physicalPlanFromFile("physical_untyped_null.json")
        .unOrdered()
        .expectsEmptyResultSet()
        .go();
  }
}