/*
 * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */
package org.mule.test.module.extension.connector;

import static java.util.Arrays.asList;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static org.hamcrest.CoreMatchers.instanceOf;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.fail;
import org.mule.runtime.api.connection.ConnectionException;
import org.mule.runtime.core.exception.MessagingException;
import org.mule.runtime.core.util.concurrent.Latch;
import org.mule.tck.junit4.rule.SystemProperty;
import org.mule.tck.probe.JUnitProbe;
import org.mule.tck.probe.PollingProber;
import org.mule.test.module.extension.config.PetStoreConnectionTestCase;
import org.mule.test.petstore.extension.PetStoreClient;
import org.mule.test.runner.RunnerDelegateTo;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

import org.junit.Rule;
import org.junit.Test;
import org.junit.runners.Parameterized;

@RunnerDelegateTo(Parameterized.class)
public class PetStoreConnectionPoolingTestCase extends PetStoreConnectionTestCase {

  private static final String CUSTOM_POOLING_CONFIG = "customPooling";
  private static final String CUSTOM_POOLING_POOLABLE_CONFIG = CUSTOM_POOLING_CONFIG + "Poolable";
  private static final String NO_POOLING = "noPooling";

  @Parameterized.Parameters(name = "{0}")
  public static Collection<Object[]> data() {
    return asList(new Object[][] {{CUSTOM_POOLING_POOLABLE_CONFIG, 3}, {NO_POOLING, 0}});
  }

  @Rule
  public SystemProperty configNameProperty;

  private ExecutorService executorService = null;
  private Latch connectionLatch = new Latch();
  private CountDownLatch testLatch;

  protected int poolSize;
  protected String name;

  public PetStoreConnectionPoolingTestCase(String name, int poolSize) {
    this.name = name;
    this.poolSize = poolSize;
    configNameProperty = new SystemProperty("configName", name);
    testLatch = new CountDownLatch(poolSize);
  }

  @Override
  protected String getConfigFile() {
    return "petstore-pooling-connection.xml";
  }

  @Override
  protected void doTearDown() throws Exception {
    if (executorService != null) {
      executorService.shutdown();
    }
  }

  @Test
  public void exhaustion() throws Exception {
    if (NO_POOLING.equals(name)) {
      // test does not apply
      return;
    }

    executorService = Executors.newFixedThreadPool(poolSize);

    List<Future<PetStoreClient>> clients = new ArrayList<>(poolSize);
    for (int i = 0; i < poolSize; i++) {
      clients.add(getClientOnLatch());
    }

    testLatch.await();

    try {
      getClient();
      fail("was expecting pool to be exhausted when using config: " + name);
    } catch (MessagingException e) {
      assertThat(e.getRootCause(), is(instanceOf(ConnectionException.class)));
    } catch (Exception e) {
      fail("a connection exception was expected");
    }

    connectionLatch.release();

    for (Future<PetStoreClient> future : clients) {
      PollingProber prober = new PollingProber(1000, 100);
      prober.check(new JUnitProbe() {

        @Override
        protected boolean test() throws Exception {
          PetStoreClient client = future.get(100, MILLISECONDS);
          assertValidClient(client);
          return true;
        }

        @Override
        public String describeFailure() {
          return "Could not obtain valid client";
        }
      });
    }

    // now test that the pool is usable again
    assertValidClient(getClient());
  }

  protected Future<PetStoreClient> getClientOnLatch() {
    return executorService
        .submit(() -> (PetStoreClient) flowRunner("getClientOnLatch").withPayload("").withVariable("testLatch", testLatch)
            .withVariable("connectionLatch", connectionLatch).run().getMessage().getPayload().getValue());
  }

  @Override
  protected void assertConnected(PetStoreClient client) {
    if (NO_POOLING.equals(name)) {
      assertThat(client.hasActiveConnection(), is(false));
    } else {
      super.assertConnected(client);
    }
  }

  @Override
  protected String getConfigName() {
    return name;
  }
}