package org.apache.helix.store.zk;

/*
 * 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.
 */

import java.lang.management.ManagementFactory;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import javax.management.JMException;
import javax.management.MBeanServer;
import javax.management.ObjectName;

import org.apache.helix.AccessOption;
import org.apache.helix.zookeeper.datamodel.ZNRecord;
import org.apache.helix.ZkUnitTestBase;
import org.apache.helix.manager.zk.ZkBaseDataAccessor;
import org.apache.helix.zookeeper.api.client.HelixZkClient;
import org.apache.helix.monitoring.mbeans.MBeanRegistrar;
import org.apache.helix.monitoring.mbeans.MonitorDomainNames;
import org.apache.helix.monitoring.mbeans.ZkClientMonitor;
import org.apache.helix.monitoring.mbeans.ZkClientPathMonitor;
import org.apache.helix.store.HelixPropertyListener;
import org.apache.helix.zookeeper.zkclient.exception.ZkNoNodeException;
import org.apache.helix.zookeeper.zkclient.serialize.SerializableSerializer;
import org.testng.Assert;
import org.testng.annotations.AfterClass;
import org.testng.annotations.Test;

public class TestZkHelixPropertyStore extends ZkUnitTestBase {
  final String _root = "/" + getShortClassName();
  final int bufSize = 128;
  final int mapNr = 10;
  final int firstLevelNr = 10;
  final int secondLevelNr = 10;

  // final int totalNodes = firstLevelNr * secondLevelNr;

  class TestListener implements HelixPropertyListener {
    Map<String, Long> _changeKeys = new HashMap<>();
    Map<String, Long> _createKeys = new HashMap<>();
    Map<String, Long> _deleteKeys = new HashMap<>();

    public void reset() {
      _changeKeys.clear();
      _createKeys.clear();
      _deleteKeys.clear();
    }

    @Override
    public void onDataChange(String path) {
      _changeKeys.put(path, System.currentTimeMillis());
    }

    @Override
    public void onDataCreate(String path) {
      _createKeys.put(path, System.currentTimeMillis());
    }

    @Override
    public void onDataDelete(String path) {
      _deleteKeys.put(path, System.currentTimeMillis());
    }
  }

  @AfterClass
  public void afterClass() {
    deleteCluster(getShortClassName());
  }

  @Test
  public void testSet() {
    // Logger.getRootLogger().setLevel(Level.INFO);

    System.out.println("START testSet() at " + new Date(System.currentTimeMillis()));

    String subRoot = _root + "/" + "set";
    List<String> subscribedPaths = new ArrayList<>();
    subscribedPaths.add(subRoot);
    ZkHelixPropertyStore<ZNRecord> store =
        new ZkHelixPropertyStore<>(new ZkBaseDataAccessor<>(_gZkClient), subRoot, subscribedPaths);

    // test set
    setNodes(store, 'a', false);
    for (int i = 0; i < 10; i++) {
      for (int j = 0; j < 10; j++) {
        String nodeId = getNodeId(i, j);
        String key = getSecondLevelKey(i, j);
        ZNRecord record = store.get(key, null, 0);
        Assert.assertEquals(record.getId(), nodeId);
      }
    }

    // test get from cache
    long startT = System.currentTimeMillis();
    for (int i = 0; i < 1000; i++) {
      ZNRecord record = store.get("/node_0/childNode_0_0", null, 0);
      Assert.assertNotNull(record);
    }
    long endT = System.currentTimeMillis();
    System.out.println("1000 Get() time used: " + (endT - startT) + "ms");
    long latency = endT - startT;
    Assert.assertTrue(latency < 200,
        "1000 Gets should be finished within 200ms, but was " + latency + " ms");

    store.stop();
    System.out.println("END testSet() at " + new Date(System.currentTimeMillis()));
  }

  @Test
  public void testSetInvalidPath() {
    String subRoot = _root + "/" + "setInvalidPath";
    ZkHelixPropertyStore<ZNRecord> store =
        new ZkHelixPropertyStore<>(new ZkBaseDataAccessor<>(_gZkClient), subRoot, null);
    try {
      store.set("abc/xyz", new ZNRecord("testInvalid"), AccessOption.PERSISTENT);
      Assert.fail("Should throw illegal-argument-exception since path doesn't start with /");
    } catch (IllegalArgumentException e) {
      // e.printStackTrace();
      // OK
    } catch (Exception e) {
      Assert.fail("Should not throw exceptions other than illegal-argument");
    }
  }

  @Test
  public void testLocalTriggeredCallback() throws Exception {
    System.out
        .println("START testLocalTriggeredCallback() at " + new Date(System.currentTimeMillis()));

    String subRoot = _root + "/" + "localCallback";
    List<String> subscribedPaths = new ArrayList<>();
    subscribedPaths.add(subRoot);
    ZkHelixPropertyStore<ZNRecord> store =
        new ZkHelixPropertyStore<>(new ZkBaseDataAccessor<>(_gZkClient), subRoot, subscribedPaths);

    // change nodes via property store interface
    // and verify all notifications have been received
    TestListener listener = new TestListener();
    store.subscribe("/", listener);

    // test dataCreate callbacks
    listener.reset();
    setNodes(store, 'a', true);

    // wait until all callbacks have been received
    Thread.sleep(500);
    int expectCreateNodes = 1 + firstLevelNr + firstLevelNr * secondLevelNr;
    System.out.println("createKey#:" + listener._createKeys.size() + ", changeKey#:"
        + listener._changeKeys.size() + ", deleteKey#:" + listener._deleteKeys.size());
    Assert.assertEquals(expectCreateNodes, listener._createKeys.size(),
        "Should receive " + expectCreateNodes + " create callbacks");

    // test dataChange callbacks
    listener.reset();
    setNodes(store, 'b', true);

    // wait until all callbacks have been received
    Thread.sleep(500);
    int expectChangeNodes = firstLevelNr * secondLevelNr;
    System.out.println("createKey#:" + listener._createKeys.size() + ", changeKey#:"
        + listener._changeKeys.size() + ", deleteKey#:" + listener._deleteKeys.size());
    Assert.assertTrue(listener._changeKeys.size() >= expectChangeNodes,
        "Should receive at least " + expectChangeNodes + " change callbacks");

    // test delete callbacks
    listener.reset();
    int expectDeleteNodes = 1 + firstLevelNr + firstLevelNr * secondLevelNr;
    store.remove("/", 0);
    // wait until all callbacks have been received
    for (int i = 0; i < 10; i++) {
      if (listener._deleteKeys.size() == expectDeleteNodes)
        break;
      Thread.sleep(500);
    }

    System.out.println("createKey#:" + listener._createKeys.size() + ", changeKey#:"
        + listener._changeKeys.size() + ", deleteKey#:" + listener._deleteKeys.size());
    Assert.assertEquals(expectDeleteNodes, listener._deleteKeys.size(),
        "Should receive " + expectDeleteNodes + " delete callbacks");

    store.stop();
    System.out
        .println("END testLocalTriggeredCallback() at " + new Date(System.currentTimeMillis()));
  }

  @Test
  public void testZkTriggeredCallback() throws Exception {
    System.out
        .println("START testZkTriggeredCallback() at " + new Date(System.currentTimeMillis()));

    String subRoot = _root + "/" + "zkCallback";
    List<String> subscribedPaths = Collections.singletonList(subRoot);
    ZkHelixPropertyStore<ZNRecord> store =
        new ZkHelixPropertyStore<>(new ZkBaseDataAccessor<>(_gZkClient), subRoot, subscribedPaths);

    // change nodes via property store interface
    // and verify all notifications have been received
    TestListener listener = new TestListener();
    store.subscribe("/", listener);

    // test create callbacks
    listener.reset();
    setNodes(_gZkClient, subRoot, 'a', true);
    int expectCreateNodes = 1 + firstLevelNr + firstLevelNr * secondLevelNr;
    Thread.sleep(500);

    System.out.println("createKey#:" + listener._createKeys.size() + ", changeKey#:"
        + listener._changeKeys.size() + ", deleteKey#:" + listener._deleteKeys.size());
    Assert.assertEquals(expectCreateNodes, listener._createKeys.size(),
        "Should receive " + expectCreateNodes + " create callbacks");

    // test change callbacks
    listener.reset();
    setNodes(_gZkClient, subRoot, 'b', true);
    int expectChangeNodes = firstLevelNr * secondLevelNr;
    for (int i = 0; i < 10; i++) {
      if (listener._changeKeys.size() >= expectChangeNodes)
        break;
      Thread.sleep(500);
    }

    System.out.println("createKey#:" + listener._createKeys.size() + ", changeKey#:"
        + listener._changeKeys.size() + ", deleteKey#:" + listener._deleteKeys.size());
    Assert.assertTrue(listener._changeKeys.size() >= expectChangeNodes,
        "Should receive at least " + expectChangeNodes + " change callbacks");

    // test delete callbacks
    listener.reset();
    int expectDeleteNodes = 1 + firstLevelNr + firstLevelNr * secondLevelNr;
    _gZkClient.deleteRecursively(subRoot);
    Thread.sleep(1000);

    System.out.println("createKey#:" + listener._createKeys.size() + ", changeKey#:"
        + listener._changeKeys.size() + ", deleteKey#:" + listener._deleteKeys.size());
    Assert.assertEquals(expectDeleteNodes, listener._deleteKeys.size(),
        "Should receive " + expectDeleteNodes + " delete callbacks");

    store.stop();
    System.out.println("END testZkTriggeredCallback() at " + new Date(System.currentTimeMillis()));
  }

  @Test
  public void testBackToBackRemoveAndSet() throws Exception {
    System.out
        .println("START testBackToBackRemoveAndSet() at " + new Date(System.currentTimeMillis()));

    String subRoot = _root + "/" + "backToBackRemoveAndSet";
    List<String> subscribedPaths = new ArrayList<>();
    subscribedPaths.add(subRoot);
    ZkHelixPropertyStore<ZNRecord> store =
        new ZkHelixPropertyStore<>(new ZkBaseDataAccessor<>(_gZkClient), subRoot, subscribedPaths);

    store.set("/child0", new ZNRecord("child0"), AccessOption.PERSISTENT);

    ZNRecord record = store.get("/child0", null, 0); // will put the record in cache
    Assert.assertEquals(record.getId(), "child0");
    // System.out.println("1:get:" + record);

    String child0Path = subRoot + "/child0";
    for (int i = 0; i < 2; i++) {
      _gZkClient.delete(child0Path);
      _gZkClient.createPersistent(child0Path, new ZNRecord("child0-new-" + i));
    }

    Thread.sleep(500); // should wait for zk callback to add "/child0" into cache
    record = store.get("/child0", null, 0);
    Assert.assertEquals(record.getId(), "child0-new-1",
        "Cache shoulde be updated to latest create");
    // System.out.println("2:get:" + record);

    _gZkClient.delete(child0Path);
    Thread.sleep(500); // should wait for zk callback to remove "/child0" from cache
    try {
      record = store.get("/child0", null, AccessOption.THROW_EXCEPTION_IFNOTEXIST);
      Assert.fail("/child0 should have been removed");
    } catch (ZkNoNodeException e) {
      // OK.
    }
    // System.out.println("3:get:" + record);

    store.stop();
    System.out
        .println("END testBackToBackRemoveAndSet() at " + new Date(System.currentTimeMillis()));
  }

  private String getNodeId(int i, int j) {
    return "childNode_" + i + "_" + j;
  }

  private String getSecondLevelKey(int i, int j) {
    return "/node_" + i + "/" + getNodeId(i, j);
  }

  private String getFirstLevelKey(int i) {
    return "/node_" + i;
  }

  private void setNodes(ZkHelixPropertyStore<ZNRecord> store, char c, boolean needTimestamp) {
    char[] data = new char[bufSize];

    for (int i = 0; i < bufSize; i++) {
      data[i] = c;
    }

    Map<String, String> map = new TreeMap<>();
    for (int i = 0; i < mapNr; i++) {
      map.put("key_" + i, new String(data));
    }

    for (int i = 0; i < firstLevelNr; i++) {
      for (int j = 0; j < secondLevelNr; j++) {
        String nodeId = getNodeId(i, j);
        ZNRecord record = new ZNRecord(nodeId);
        record.setSimpleFields(map);
        if (needTimestamp) {
          long now = System.currentTimeMillis();
          record.setSimpleField("SetTimestamp", Long.toString(now));
        }
        String key = getSecondLevelKey(i, j);
        store.set(key, record, AccessOption.PERSISTENT);
      }
    }
  }

  private void setNodes(HelixZkClient zkClient, String root, char c, boolean needTimestamp) {
    char[] data = new char[bufSize];

    for (int i = 0; i < bufSize; i++) {
      data[i] = c;
    }

    Map<String, String> map = new TreeMap<>();
    for (int i = 0; i < mapNr; i++) {
      map.put("key_" + i, new String(data));
    }

    for (int i = 0; i < firstLevelNr; i++) {
      String firstLevelKey = getFirstLevelKey(i);

      for (int j = 0; j < secondLevelNr; j++) {
        String nodeId = getNodeId(i, j);
        ZNRecord record = new ZNRecord(nodeId);
        record.setSimpleFields(map);
        if (needTimestamp) {
          long now = System.currentTimeMillis();
          record.setSimpleField("SetTimestamp", Long.toString(now));
        }
        String key = getSecondLevelKey(i, j);
        try {
          zkClient.writeData(root + key, record);
        } catch (ZkNoNodeException e) {
          zkClient.createPersistent(root + firstLevelKey, true);
          zkClient.createPersistent(root + key, record);
        }
      }
    }
  }

  @Test
  public void testZkClientMonitor() throws JMException {
    final String TEST_ROOT = "/test_root";

    ZkHelixPropertyStore<ZNRecord> store =
        new ZkHelixPropertyStore<>(ZK_ADDR, new SerializableSerializer(), TEST_ROOT);

    ObjectName name = MBeanRegistrar.buildObjectName(MonitorDomainNames.HelixZkClient.name(),
        ZkClientMonitor.MONITOR_TYPE, ZkHelixPropertyStore.MONITOR_TYPE,
        ZkClientMonitor.MONITOR_KEY, TEST_ROOT, ZkClientPathMonitor.MONITOR_PATH, "Root");
    MBeanServer beanServer = ManagementFactory.getPlatformMBeanServer();
    Assert.assertTrue(beanServer.isRegistered(name));

    store.getStat("/", AccessOption.PERSISTENT);

    Assert.assertEquals((long) beanServer.getAttribute(name, "ReadCounter"), 1);
  }
}
