/*
 * Copyright (C) 2020 IBM Corporation
 *
 * 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.vertx.db2client;

import static org.junit.Assume.assumeTrue;

import java.sql.RowId;
import java.time.LocalDateTime;
import java.time.temporal.ChronoField;
import java.util.Arrays;
import java.util.UUID;

import org.junit.Test;
import org.junit.runner.RunWith;

import io.vertx.core.buffer.Buffer;
import io.vertx.ext.unit.TestContext;
import io.vertx.ext.unit.junit.VertxUnitRunner;
import io.vertx.sqlclient.Row;
import io.vertx.sqlclient.RowSet;
import io.vertx.sqlclient.Tuple;

@RunWith(VertxUnitRunner.class)
public class DB2DataTypeTest extends DB2TestBase {

  /**
   * In DB2 the FLOAT and DOUBLE column types both map to an 8-byte
   * double-precision column (i.e. Java double). Ensure that a Java
   * float can still be inserted and selected from such a column
   */
  @Test
  public void testFloatIntoFloatColumn(TestContext ctx) {
      connect(ctx.asyncAssertSuccess(conn -> {
          conn.preparedQuery("INSERT INTO db2_types (id,test_float) VALUES (?, ?)")
            .execute(Tuple.of(1, 5.0f), ctx.asyncAssertSuccess(insertResult -> {
               conn.preparedQuery("SELECT id,test_float FROM db2_types WHERE id = 1")
                 .execute(ctx.asyncAssertSuccess(rows -> {
                   ctx.assertEquals(1, rows.size());
                   Row row = rows.iterator().next();
                   ctx.assertEquals(1, row.getInteger(0));
                   ctx.assertEquals(5.0f, row.getFloat(1));
                 }));
            }));
        }));
  }

  /**
   * DB2 has no BYTE or BOOLEAN column type, and instead maps it to a
   * 2-byte SMALLINT column type. This means Java byte types must be
   * converted into SMALLINT formats
   */
  @Test
  public void testByteIntoSmallIntColumn(TestContext ctx) {
      connect(ctx.asyncAssertSuccess(conn -> {
          conn.preparedQuery("INSERT INTO db2_types (id,test_byte) VALUES (?, ?)")
            .execute(Tuple.of(2, (byte) 0xCA), ctx.asyncAssertSuccess(insertResult -> {
               conn.preparedQuery("SELECT id,test_byte FROM db2_types WHERE id = 2")
                 .execute(ctx.asyncAssertSuccess(rows -> {
                   ctx.assertEquals(1, rows.size());
                   Row row = rows.iterator().next();
                   ctx.assertEquals(2, row.getInteger(0));
                   ctx.assertEquals((byte) 0xCA, row.get(Byte.class, 1));
                 }));
            }));
        }));
  }

  @Test
  public void testByteArrayIntoVarchar(TestContext ctx) {
    byte[] expected = "hello world".getBytes();
    connect(ctx.asyncAssertSuccess(conn -> {
      conn.preparedQuery("INSERT INTO db2_types (id,test_bytes) VALUES (?, ?)")
          .execute(Tuple.of(3, "hello world".getBytes()), ctx.asyncAssertSuccess(insertResult -> {
            conn.preparedQuery("SELECT id,test_bytes FROM db2_types WHERE id = 3")
                .execute(ctx.asyncAssertSuccess(rows -> {
                  ctx.assertEquals(1, rows.size());
                  Row row = rows.iterator().next();
                  ctx.assertEquals(3, row.getInteger(0));
                  ctx.assertTrue(Arrays.equals(expected, row.getBuffer(1).getBytes()),
                      "Expecting " + Arrays.toString(expected) + " but got "
                          + Arrays.toString(row.getBuffer(1).getBytes()));
                }));
          }));
    }));
  }

  @Test
  public void testByteBufIntoVarchar(TestContext ctx) {
    byte[] expected = "hello world".getBytes();
    connect(ctx.asyncAssertSuccess(conn -> {
      conn.preparedQuery("INSERT INTO db2_types (id,test_bytes) VALUES (?, ?)")
          .execute(Tuple.of(4, Buffer.buffer(expected)), ctx.asyncAssertSuccess(insertResult -> {
            conn.preparedQuery("SELECT id,test_bytes FROM db2_types WHERE id = 4")
                .execute(ctx.asyncAssertSuccess(rows -> {
                  ctx.assertEquals(1, rows.size());
                  Row row = rows.iterator().next();
                  ctx.assertEquals(4, row.getInteger(0));
                  ctx.assertTrue(Arrays.equals(expected, row.getBuffer(1).getBytes()),
                      "Expecting " + Arrays.toString(expected) + " but got "
                          + Arrays.toString(row.getBuffer(1).getBytes()));
                }));
          }));
    }));
  }

  @Test
  public void testTimestamp(TestContext ctx) {
    LocalDateTime now = LocalDateTime.now();
    connect(ctx.asyncAssertSuccess(conn -> {
      conn.preparedQuery("INSERT INTO db2_types (id,test_tstamp) VALUES (?,?)")
        .execute(Tuple.of(5, now), ctx.asyncAssertSuccess(insertResult -> {
           conn.preparedQuery("SELECT id,test_tstamp FROM db2_types WHERE id = ?")
             .execute(Tuple.of(5), ctx.asyncAssertSuccess(rows -> {
          ctx.assertEquals(1, rows.size());
          Row row = rows.iterator().next();
          int nowNanos = now.getNano() - (1000 * now.get(ChronoField.MICRO_OF_SECOND));
          int dbNanos = row.getLocalDateTime(1).getNano() - (1000 * row.getLocalDateTime(1).get(ChronoField.MICRO_OF_SECOND));
          ctx.assertEquals(5, row.getInteger(0));
          ctx.assertEquals(dbNanos > 0 ? now : now.minusNanos(nowNanos), row.getLocalDateTime(1));
             }));
        }));
    }));
  }

  @Test
  public void testUUID(TestContext ctx) {
    UUID uuid = UUID.randomUUID();
    connect(ctx.asyncAssertSuccess(conn -> {
      conn.preparedQuery("INSERT INTO db2_types (id,test_vchar) VALUES (?,?)").execute(Tuple.of(6, uuid),
          ctx.asyncAssertSuccess(insertResult -> {
            conn.preparedQuery("SELECT id,test_vchar FROM db2_types WHERE id = ?").execute(Tuple.of(6),
                ctx.asyncAssertSuccess(rows -> {
                  ctx.assertEquals(1, rows.size());
                  Row row = rows.iterator().next();
                  ctx.assertEquals(6, row.getInteger(0));
                  ctx.assertEquals(uuid, row.getUUID(1));
                  ctx.assertEquals(uuid, row.getUUID("test_vchar"));
                  ctx.assertEquals(uuid, row.get(UUID.class, 1));
                }));
          }));
    }));
  }

  @Test
  public void testRowId(TestContext ctx) {
    assumeTrue("Only DB2/Z supports the ROWID column type", rule.isZOS());

    final String msg = "insert data for testRowId";
    connect(ctx.asyncAssertSuccess(conn -> {
      // Insert some data
      conn.preparedQuery("INSERT INTO ROWTEST (message) VALUES ('" + msg + "')")
        .execute(ctx.asyncAssertSuccess(insertResult -> {
           // Find it by msg
           conn.preparedQuery("SELECT * FROM ROWTEST WHERE message = '" + msg + "'")
             .execute(ctx.asyncAssertSuccess(rows -> {
               RowId rowId = verifyRowId(ctx, rows, msg);
               // Now find it by rowid
               conn.preparedQuery("SELECT * FROM ROWTEST WHERE id = ?")
                 .execute(Tuple.of(rowId), ctx.asyncAssertSuccess(rows2 -> {
                   verifyRowId(ctx, rows2, msg);
                 }));
             }));
        }));
    }));
  }

  private RowId verifyRowId(TestContext ctx, RowSet<Row> rows, String msg) {
    ctx.assertEquals(1, rows.size());
    Row row = rows.iterator().next();
    ctx.assertEquals(msg, row.getString(1));
    RowId rowid = row.get(RowId.class, 0);
    ctx.assertNotNull(rowid);
    ctx.assertEquals(22, rowid.getBytes().length);
    return rowid;
  }
}