/*
 * 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.geode.internal.compression;

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

import org.junit.Test;

import org.apache.geode.cache.DataPolicy;
import org.apache.geode.cache.Region;
import org.apache.geode.compression.Compressor;
import org.apache.geode.compression.SnappyCompressor;
import org.apache.geode.test.dunit.Host;
import org.apache.geode.test.dunit.SerializableCallable;
import org.apache.geode.test.dunit.SerializableRunnable;
import org.apache.geode.test.dunit.VM;
import org.apache.geode.test.dunit.cache.internal.JUnit4CacheTestCase;

/**
 * Tests that the compressor region attribute is properly set or rejected by a RegionFactory.
 */

public class CompressionRegionFactoryDUnitTest extends JUnit4CacheTestCase {
  /**
   * Compressed region name.
   */
  protected static final String COMPRESSED_REGION_NAME = "compressedRegion";

  /**
   * A valid compressor.
   */
  protected static final Compressor compressor = new SnappyCompressor();

  /**
   * Our test vm.
   */
  protected static final int TEST_VM = 0;

  public CompressionRegionFactoryDUnitTest() {
    super();
  }

  /**
   * Asserts that a region is created when a valid compressor is used. Asserts that the region
   * attributes contain the correct compressor value.
   */
  @Test
  public void testRegionFactoryCompressor() {
    assertTrue(createCompressedRegionOnVm(getVM(TEST_VM), COMPRESSED_REGION_NAME, compressor));
    assertCompressor(getVM(TEST_VM), COMPRESSED_REGION_NAME, compressor);
    cleanup(getVM(TEST_VM));
  }

  /**
   * Returns the VM for a given identifier.
   *
   * @param vm a virtual machine identifier.
   */
  private VM getVM(int vm) {
    return Host.getHost(0).getVM(vm);
  }

  /**
   * Removes created regions from a VM.
   *
   * @param vm the virtual machine to cleanup.
   */
  private void cleanup(final VM vm) {
    vm.invoke(new SerializableRunnable() {
      @Override
      public void run() {
        getCache().getRegion(COMPRESSED_REGION_NAME).destroyRegion();
      }
    });
  }

  /**
   * Asserts that a given compressor has been assigned to a region.
   *
   * @param vm the virtual machine to run the assertions on.
   * @param name a region name.
   * @param compressor a compressor.
   */
  private void assertCompressor(final VM vm, final String name, final Compressor compressor) {
    vm.invoke(new SerializableRunnable() {
      @Override
      public void run() {
        Region region = getCache().getRegion(name);
        assertNotNull(region);
        assertNotNull(region.getAttributes().getCompressor());
        assertTrue(compressor.equals(region.getAttributes().getCompressor()));
      }
    });
  }

  /**
   * Creates a region and assigns a compressor.
   *
   * @param vm a virtual machine to create the region on.
   * @param name a region name.
   * @param compressor a compressor.
   * @return true if successfully created, otherwise false.
   */
  private boolean createCompressedRegionOnVm(final VM vm, final String name,
      final Compressor compressor) {
    return (Boolean) vm.invoke(new SerializableCallable() {
      @Override
      public Object call() throws Exception {
        try {
          createRegion(name, compressor);
        } catch (IllegalStateException e) {
          return Boolean.FALSE;
        }

        return Boolean.TRUE;
      }
    });
  }

  /**
   * Creates a region and assigns a compressor.
   *
   * @param name a region name.
   * @param compressor a compressor.
   */
  private Region createRegion(String name, Compressor compressor) {
    return getCache().<String, String>createRegionFactory().setDataPolicy(DataPolicy.REPLICATE)
        .setCloningEnabled(true).setCompressor(compressor).create(name);
  }
}
