/*
    * 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
    *
    *      https://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.commons.lang3.concurrent;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertNull;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  import java.io.IOException;
  import java.nio.file.FileSystemException;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicBoolean;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.apache.commons.lang3.exception.ExceptionUtils;
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.api.Timeout;
  import org.junit.jupiter.api.Timeout.ThreadMode;
  import org.junit.jupiter.params.ParameterizedTest;
  import org.junit.jupiter.params.provider.ValueSource;
  
  /**
   * Test class for {@code AtomicSafeInitializer} which also serves as a simple example.
   */
  class AtomicSafeInitializerTest extends AbstractConcurrentInitializerTest<Object> {
  
      /**
       * A concrete test implementation of {@code AtomicSafeInitializer} which also serves as a simple example.
       * <p>
       * This implementation also counts the number of invocations of the initialize() method.
       * </p>
       */
      private static final class AtomicSafeInitializerTestImpl extends AtomicSafeInitializer<Object> {
  
          /** A counter for initialize() invocations. */
          final AtomicInteger initCounter = new AtomicInteger();
  
          @Override
          protected Object initialize() {
              initCounter.incrementAndGet();
              return new Object();
          }
      }
  
      /** The instance to be tested. */
      private AtomicSafeInitializerTestImpl initializer;
  
      /**
       * Returns the initializer to be tested.
       *
       * @return the {@code AtomicSafeInitializer} under test.
       */
      @Override
      protected ConcurrentInitializer<Object> createInitializer() {
          return initializer;
      }
  
      @BeforeEach
      public void setUp() {
          initializer = new AtomicSafeInitializerTestImpl();
      }
  
      @Test
      void testGetThatReturnsNullFirstTime() throws ConcurrentException {
          final AtomicSafeInitializer<Object> initializer = new AtomicSafeInitializer<Object>() {
  
              final AtomicBoolean firstRun = new AtomicBoolean(true);
  
              @Override
              protected Object initialize() {
                  if (firstRun.getAndSet(false)) {
                      return null;
                  }
                  return new Object();
              }
          };
          assertNull(initializer.get());
          assertNull(initializer.get());
      }
  
      @ParameterizedTest
      @ValueSource(classes = { IOException.class, Exception.class, FileSystemException.class, ReflectiveOperationException.class, ConcurrentException.class })
      @Timeout(value = 5, unit = TimeUnit.SECONDS, threadMode = ThreadMode.SAME_THREAD)
     void testInitializerThrowsChecked(final Class<Exception> throwableClass) throws ConcurrentException {
         final String message = "Initializing";
         final AtomicSafeInitializer<Object> asi = AtomicSafeInitializer.builder().setInitializer(() -> {
             throw throwableClass.getConstructor(String.class).newInstance(message);
         }).get();
         final String expected = throwableClass.getSimpleName() + ": " + message;
         assertEquals(expected, ExceptionUtils.getRootCauseMessage(assertThrows(ConcurrentException.class, asi::get)));
         assertEquals(expected, ExceptionUtils.getRootCauseMessage(assertThrows(ConcurrentException.class, asi::get)));
     }
 
     @ParameterizedTest
     @ValueSource(classes = { IllegalStateException.class, IllegalArgumentException.class, NullPointerException.class, RuntimeException.class })
     @Timeout(value = 5, unit = TimeUnit.SECONDS, threadMode = ThreadMode.SAME_THREAD)
     void testInitializerThrowsUnchecked(final Class<Exception> throwableClass) throws ConcurrentException {
         final String message = "Initializing";
         final AtomicSafeInitializer<Object> asi = AtomicSafeInitializer.builder().setInitializer(() -> {
             throw throwableClass.getConstructor(String.class).newInstance(message);
         }).get();
         assertEquals(message, assertThrows(throwableClass, asi::get).getMessage());
         assertEquals(message, assertThrows(throwableClass, asi::get).getMessage());
     }
 
     /**
      * Tests that initialize() is called only once.
      *
      * @throws org.apache.commons.lang3.concurrent.ConcurrentException because {@link #testGetConcurrent()} may throw it.
      * @throws InterruptedException                                    because {@link #testGetConcurrent()} may throw it.
      */
     @Test
     void testNumberOfInitializeInvocations() throws ConcurrentException, InterruptedException {
         testGetConcurrent();
         assertEquals(1, initializer.initCounter.get(), "Wrong number of invocations");
     }
 }