/**
 * 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.sqoop;

import java.io.IOException;
import java.util.ArrayList;

import org.apache.commons.cli.ParseException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.util.ReflectionUtils;

import org.apache.sqoop.SqoopOptions;
import org.apache.sqoop.SqoopOptions.InvalidOptionsException;
import org.apache.sqoop.orm.CompilationManager;
import org.apache.sqoop.testutil.CommonArgs;
import org.apache.sqoop.testutil.HsqldbTestServer;
import org.apache.sqoop.testutil.ImportJobTestCase;
import org.apache.sqoop.testutil.SeqFileReader;
import org.apache.sqoop.tool.ImportTool;
import org.apache.sqoop.util.ClassLoaderStack;
import org.junit.Test;

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

/**
 * Test that --query works in Sqoop.
 */
public class TestQuery extends ImportJobTestCase {

  /**
   * Create the argv to pass to Sqoop.
   * @return the argv as an array of strings.
   */
  protected String [] getArgv(boolean includeHadoopFlags, String query,
      String targetDir, boolean allowParallel) {

    ArrayList<String> args = new ArrayList<String>();

    if (includeHadoopFlags) {
      CommonArgs.addHadoopFlags(args);
    }

    args.add("--query");
    args.add(query);
    args.add("--split-by");
    args.add("INTFIELD1");
    args.add("--connect");
    args.add(HsqldbTestServer.getUrl());
    args.add("--as-sequencefile");
    args.add("--target-dir");
    args.add(targetDir);
    args.add("--class-name");
    args.add(getTableName());
    if (allowParallel) {
      args.add("--num-mappers");
      args.add("2");
    } else {
      args.add("--num-mappers");
      args.add("1");
    }

    return args.toArray(new String[0]);
  }

  // this test just uses the two int table.
  protected String getTableName() {
    return HsqldbTestServer.getTableName();
  }


  /**
   * Given a comma-delimited list of integers, grab and parse the first int.
   * @param str a comma-delimited list of values, the first of which is an int.
   * @return the first field in the string, cast to int
   */
  private int getFirstInt(String str) {
    String [] parts = str.split(",");
    return Integer.parseInt(parts[0]);
  }

  public void runQueryTest(String query, String firstValStr,
      int numExpectedResults, int expectedSum, String targetDir)
      throws IOException {

    ClassLoader prevClassLoader = null;
    SequenceFile.Reader reader = null;

    String [] argv = getArgv(true, query, targetDir, false);
    runImport(argv);
    try {
      SqoopOptions opts = new ImportTool().parseArguments(
          getArgv(false, query, targetDir, false),
          null, null, true);

      CompilationManager compileMgr = new CompilationManager(opts);
      String jarFileName = compileMgr.getJarFilename();

      prevClassLoader = ClassLoaderStack.addJarFile(jarFileName,
          getTableName());

      reader = SeqFileReader.getSeqFileReader(getDataFilePath().toString());

      // here we can actually instantiate (k, v) pairs.
      Configuration conf = new Configuration();
      Object key = ReflectionUtils.newInstance(reader.getKeyClass(), conf);
      Object val = ReflectionUtils.newInstance(reader.getValueClass(), conf);

      if (reader.next(key) == null) {
        fail("Empty SequenceFile during import");
      }

      // make sure that the value we think should be at the top, is.
      reader.getCurrentValue(val);
      assertEquals("Invalid ordering within sorted SeqFile", firstValStr,
          val.toString());

      // We know that these values are two ints separated by a ',' character.
      // Since this is all dynamic, though, we don't want to actually link
      // against the class and use its methods. So we just parse this back
      // into int fields manually.  Sum them up and ensure that we get the
      // expected total for the first column, to verify that we got all the
      // results from the db into the file.
      int curSum = getFirstInt(val.toString());
      int totalResults = 1;

      // now sum up everything else in the file.
      while (reader.next(key) != null) {
        reader.getCurrentValue(val);
        curSum += getFirstInt(val.toString());
        totalResults++;
      }

      assertEquals("Total sum of first db column mismatch", expectedSum,
          curSum);
      assertEquals("Incorrect number of results for query", numExpectedResults,
          totalResults);
    } catch (InvalidOptionsException ioe) {
      fail(ioe.toString());
    } catch (ParseException pe) {
      fail(pe.toString());
    } finally {
      IOUtils.closeStream(reader);

      if (null != prevClassLoader) {
        ClassLoaderStack.setCurrentClassLoader(prevClassLoader);
      }
    }
  }

  @Test
  public void testSelectStar() throws IOException {
    runQueryTest("SELECT * FROM " + getTableName()
        + " WHERE INTFIELD2 > 4 AND $CONDITIONS",
        "1,8\n", 2, 4, getTablePath().toString());
  }

  @Test
  public void testCompoundWhere() throws IOException {
    runQueryTest("SELECT * FROM " + getTableName()
        + " WHERE INTFIELD1 > 4 AND INTFIELD2 < 3 AND $CONDITIONS",
        "7,2\n", 1, 7, getTablePath().toString());
  }

  @Test
  public void testFailNoConditions() throws IOException {
    String [] argv = getArgv(true, "SELECT * FROM " + getTableName(),
        getTablePath().toString(), true);
    try {
      runImport(argv);
      fail("Expected exception running import without $CONDITIONS");
    } catch (Exception e) {
      LOG.info("Got exception " + e + " running job (expected; ok)");
    }
  }
}