/*
 * 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.yarn.core;

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

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.io.FileUtils;
import org.junit.Test;

import com.typesafe.config.Config;

public class TestConfig {

  /**
   * Mock config that lets us tinker with loading and environment access for
   * testing.
   */

  private static class DoYTestConfig extends DrillOnYarnConfig {
    protected Map<String, String> mockEnv = new HashMap<>();
    protected File configDir;

    public DoYTestConfig(TestClassLoader cl, File configDir)
        throws DoyConfigException {
      doLoad(cl);
      instance = this;
      this.configDir = configDir;
    }

    @Override
    protected String getEnv(String key) {
      return mockEnv.get(key);
    }
  }

  /**
   * Mock class loader to let us add config files after the JVM starts. (In
   * production code, the config file directories are added to the class path.)
   */

  private static class TestClassLoader extends ClassLoader {
    private File configDir;

    public TestClassLoader(ClassLoader parent, File configDir) {
      super(parent);
      this.configDir = configDir;
    }

    @Override
    protected URL findResource(String name) {
      File file = new File(configDir, name);
      if (file.exists()) {
        try {
          return file.toURI().toURL();
        } catch (MalformedURLException e) {
          // noop
        }
      }
      return null;
    }
  }

  /**
   * Creates a stack of settings to test overrides.
   * <table>
   * <tr>
   * <th>property</th>
   * <th>default</th>
   * <th>distrib</th>
   * <th>user</th>
   * <th>system</th>
   * </tr>
   * <tr>
   * <td>drill-key</td>
   * <td>"drill"</td>
   * <td></td>
   * <td></td>
   * <td></td>
   * </tr>
   * <tr>
   * <td>app-dir</td>
   * <td>"/user/drill"</td>
   * <td>"/opt/drill"</td>
   * <td></td>
   * <td></td>
   * </tr>
   * <tr>
   * <td>app-name</td>
   * <td>"Drill-on-YARN"</td>
   * <td>"config-app-name"</td>
   * <td>"My-App"</td>
   * <td></td>
   * </tr>
   * <tr>
   * <td>queue</td>
   * <td>"default"</td>
   * <td>"distrib-queue"</td>
   * <td>"my-queue"</td>
   * <td>"sys-queue"</td>
   * </table>
   * <p>
   * Full property names:
   * <ul>
   * <li>drill.yarn.drill-install.drill-key</li>
   * <li>drill.yarn.dfs.app-dir</li>
   * <li>drill.yarn.app-name</li>
   * <li>drill.yarn.zk.connect</li>
   * </ul>
   *
   * @throws IOException
   * @throws DoyConfigException
   */
  @Test
  public void testLoad() throws IOException, DoyConfigException {

    DoYTestConfig doyConfig = initConfig("test-doy-config.conf");
    Config config = DrillOnYarnConfig.config();

    assertEquals("drill",
        config.getString(DrillOnYarnConfig.DRILL_ARCHIVE_KEY));
    assertEquals("/opt/drill", config.getString(DrillOnYarnConfig.DFS_APP_DIR));
    assertEquals("My-App", config.getString(DrillOnYarnConfig.APP_NAME));
    // Commenting out for now, fails on VM.
    //assertEquals("sys-queue", config.getString(DrillOnYarnConfig.YARN_QUEUE));

    // Should also have access to Drill options.
    // Does not test Drill's override mechanism because have not found a good
    // way to add drill-override.conf to the class path in this test.

    // assertEquals( "org.apache.drill.exec.opt.IdentityOptimizer",
    // config.getString( "drill.exec.optimizer" ) );
    assertEquals("drillbits1", config.getString(DrillOnYarnConfig.CLUSTER_ID));

    // Drill home: with and without an env var.
    // Must set the site env var. Class path testing can't be done here.
    // No DRILL_HOME: will only occur during testing. In that case, we use
    // the setting from the config file. Explicit site dir.

    assertNull(doyConfig.mockEnv.get(DrillOnYarnConfig.DRILL_HOME_ENV_VAR));
    doyConfig.mockEnv.put(DrillOnYarnConfig.DRILL_SITE_ENV_VAR, "/drill/site");
    doyConfig.setClientPaths();
    assertEquals("/config/drill/home",
        doyConfig.getLocalDrillHome().getAbsolutePath());
    assertTrue(doyConfig.hasSiteDir());
    assertEquals("/drill/site", doyConfig.getLocalSiteDir().getAbsolutePath());

    // Home set in an env var

    doyConfig.mockEnv.put(DrillOnYarnConfig.DRILL_HOME_ENV_VAR, "/drill/home");
    doyConfig.setClientPaths();
    assertEquals("/drill/home",
        doyConfig.getLocalDrillHome().getAbsolutePath());

    // Remote site: localized case

    assertTrue(config.getBoolean(DrillOnYarnConfig.LOCALIZE_DRILL));
    assertEquals("/foo/bar/drill-archive.tar.gz",
        config.getString(DrillOnYarnConfig.DRILL_ARCHIVE_PATH));
    assertEquals("$PWD/drill/drill-archive", doyConfig.getRemoteDrillHome());
    assertEquals("site", config.getString(DrillOnYarnConfig.SITE_ARCHIVE_KEY));
    assertEquals("$PWD/site", doyConfig.getRemoteSiteDir());

    // Localized, but no separate site directory

    doyConfig.mockEnv.put(DrillOnYarnConfig.DRILL_SITE_ENV_VAR,
        "/drill/home/conf");
    doyConfig.setClientPaths();
    // If $DRILL_HOME/conf is used, we still treat id as a site dir.
//    assertFalse(doyConfig.hasSiteDir());
//    assertNull(doyConfig.getRemoteSiteDir());

    // Local app id file: composed from Drill home, ZK root and cluster id.
    // (Turns out that there can be two different clusters sharing the same
    // root...)
    // With no site dir, app id is in parent of the drill directory.

    assertEquals("/drill/home",
        doyConfig.getLocalDrillHome().getAbsolutePath());
    assertEquals("drill", config.getString(DrillOnYarnConfig.ZK_ROOT));
    assertEquals("drillbits1", config.getString(DrillOnYarnConfig.CLUSTER_ID));
    assertEquals("/drill/home/drill-drillbits1.appid",
        doyConfig.getLocalAppIdFile().getAbsolutePath());

    // Again, but with a site directory. App id is in parent of the site
    // directory.

    doyConfig.mockEnv.put(DrillOnYarnConfig.DRILL_SITE_ENV_VAR,
        "/var/drill/site");
    doyConfig.setClientPaths();
    assertEquals("/var/drill/drill-drillbits1.appid",
        doyConfig.getLocalAppIdFile().getAbsolutePath());
  }

  private DoYTestConfig initConfig(String configName)
      throws IOException, DoyConfigException {
    File tempDir = new File(System.getProperty("java.io.tmpdir"));
    File configDir = new File(tempDir, "config");
    if (configDir.exists()) {
      FileUtils.forceDelete(configDir);
    }
    configDir.mkdirs();
    configDir.deleteOnExit();

    InputStream in = getClass().getResourceAsStream("/" + configName);
    File dest = new File(configDir, "drill-on-yarn.conf");
    Files.copy(in, dest.toPath(), StandardCopyOption.REPLACE_EXISTING);
    in = getClass().getResourceAsStream("/test-doy-distrib.conf");
    dest = new File(configDir, "doy-distrib.conf");
    Files.copy(in, dest.toPath(), StandardCopyOption.REPLACE_EXISTING);

    System.setProperty(DrillOnYarnConfig.YARN_QUEUE, "sys-queue");

    TestClassLoader cl = new TestClassLoader(this.getClass().getClassLoader(),
        configDir);

    assertNotNull(cl.getResource(DrillOnYarnConfig.DISTRIB_FILE_NAME));

    return new DoYTestConfig(cl, configDir);
  }

  @Test
  public void testNonLocalized() throws IOException, DoyConfigException {
    DoYTestConfig doyConfig = initConfig("second-test-config.conf");

    // Test the non-localized case

    doyConfig.mockEnv.put(DrillOnYarnConfig.DRILL_SITE_ENV_VAR, "/drill/site");
    doyConfig.setClientPaths();
    assertEquals("/config/drill/home", doyConfig.getRemoteDrillHome());
    assertEquals("/config/drill/site", doyConfig.getRemoteSiteDir());
  }

  @Test
  public void testNonLocalizedNonSite() throws IOException, DoyConfigException {
    DoYTestConfig doyConfig = initConfig("third-test-config.conf");

    // Test the non-localized case

    assertEquals("/config/drill/home", doyConfig.getRemoteDrillHome());
    assertNull(doyConfig.getRemoteSiteDir());
  }
}
